105 directive storage flammable liquids (pgs 29).pdf
TRANSCRIPT
29
Directive for
aboveground
storage of flammable
liquids in vertical
cylindrical tanks
PUBLICATION SERIES
HAZARDOUS SUBSTANCES
Lid van het Nederlands Genootschap van Tolken en Vertalers
2
“VROM” Ministry of Housing, Spatial Planning and the Environment
Directorate of External Safety
Rijnstraat 8
P.O. Box 20951
2500 EZ The Hague
www.vrom.nl
Publication Series Hazardous
Substances 29
Directive for aboveground storage
of flammable liquids
in vertical cylindrical tanks
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Preface
As per June 1, 2004, the Advisory Council Hazardous Substances (“AGS”) was appointed by the
government. The Committee of Prevention of Disasters due to hazardous substances (“CPR”) was
also discontinued. The CPR issued publications, the CPR Directives, that are often used when
licenses are granted in pursuance of the Environmental Management Act and within the fields of
work safety, transportation safety, and fire safety.
The CPR Directives were converted into the Publication Series Hazardous Substances. The object
of these publications is roughly the same as of the CPR Directives, notably to give an overview,
based on the status of technology, of the regulations, requirements, criteria and conditions that can
be applied by authorities when granting licenses to and supervising companies that work with
hazardous substances. When converted into “PGS” publications, all CPR Directives were
evaluated from the following questions:
- is there still a reason for the directive to exist or can the directive be cancelled, and
- can the directive be copied without amendment or is it necessary to update it.
This publication is an update and combination of the directives:
- CPR 9-2 “LIQUID PETROLEUM PRODUCTS, aboveground storage small installations” and
- CPR 9-3 “LIQUID PETROLEUM PRODUCTS, underground storage large installations”
After this conversion, the PGS 29 was subsequently amended in connection with the explosion
and fire in the Buncefield fuel depot in British Hemel Hampstead. An expert task force consisting
of government and industry translated and processed the investigation results and
recommendations of the Buncefield investigation into the Netherlands approach.
The input for this work consists of three reports:
- Recommendations on the design and operation of fuel storage tanks 03/2007, issued by the
Buncefield Major Incident Investigation Board (BMIIB);
- Recommendations on the preparedness for, response to, and recovery from incidents 07-2007,
issued by BMIIB;
- Safety and environmental standards for fuel storage sites 07-2007, issued by the Buncefield
Standard Task Force Group (BSTG)
The PGS 29 has been prepared within the structure of the CPR by the sub-committee “Storage
liquid petroleum products”. The Interprovincial Committee (“IPO”), the Association of
Netherlands Municipalities (“VNG”), and the business community (“VNO-NCW” and “MKB”
the Netherlands) had already given a positive advice earlier on issuing this publication.
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table of contents
1 Introduction
1.1 Amendments new directive compared to CPR 9-2/3
1.2 Starting points
2 Object, field of application, and use
2.1 Object of this directive
2.2 Field of application
2.2.1 In General
2.2.2 Exceptions for substances
2.2.3 Exceptions for activities
2.3 Use of this directive
3 Definitions and terms
4 Tank storage, activities, and design
4.1 Activity
4.2 Design of the site
4.3 Mutual distances
4.4 Sewage system and drainage
4.5 Electrical installation and grounding
4.5.1 Electrical installation
4.5.2 Grounding
4.5.3 Measures against static electricity
4.6 Danger zone design
4.7 Hydrogen sulfide
5 Tank farm containment areas
5.1 Permitted activities in the tank farm containment area
5.2 Minimum distances within the tank farm containment area
5.3 Collecting capacity of the tank farm containment area
5.4 Construction of the tank farm containment area
5.4.1 Tank farm containment area floor
5.4.2 Dikes
5.4.3 Ducts
5.4.4 Access to the tank farm containment area
5.5 Sewage system
5.6 Drainage of firewater
5.7 Product pump in the tank farm containment area
5.8 Pipes and shut-off valves in the tank farm containment area
6 Storage tanks
6.1 General requirements
6.1.1 Construction
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6.1.2 Calculation bases
6.2 Access to tank roofs
6.3 Tank equipment
6.3.1 Aerating a tank with a fixed roof
6.3.2 Aerating a tank with a floating roof
6.3.3 Seal materials and workable ranges of seals
6.3.4 Shut-off valves
6.3.5 Anchors
6.3.6 High-level alert and overfill protection
6.4 Non-destructive examination of welds after new construction of tanks
7 Other facilities
7.1 Vapor processing installation and/or vapor return system
7.2 Pump-pads
7.3 Transfer
7.3.1 General requirements
7.3.2 Tank trucks and train tank wagons (loading and unloading stations)
7.3.3 Ships (piers)
7.4 Product pipes and pipe tracks
7.5 Product shut-off valves
7.6 Utilities
7.7 Offices, workshops, and laboratories
7.8 Control rooms
8 Firefighting facilities
8.1 In general
8.2 Fire extinguishers
8.3 Firewater system
8.3.1 Capacity of firewater system
8.3.2 Design of the firewater system
8.3.3 Firewater pump system
8.4 Refrigerating systems
8.5 Foam extinguishers
8.6 Fire detection
8.7 Report and alert facilities
8.8 Other facilities
9 Safety control measures
9.1 Safety policy
9.2 Staff: skill, training, alertness
9.3 Scenario description and accident analysis
9.4 Supervision over the execution
9.5 Being prepared for and respond to emergency situations
9.5.1 Procedures and instructions
9.5.2 Incident and accident report
9.5.3 Drill
9.6 Cooperation
9.6.1 Supervision over performances
9.7 Assessment and evaluation
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10 Fire prevention and safety
10.1 Tests upon delivery
10.1.1 Installation pipes
10.1.2 Tank heating
10.2 Independent supervision
10.3 Inspection program
10.4 New construction certificate
10.5 Safety systems
11 Business operations and management
11.1 Operational supervision and inspection
11.2 Work permits
11.3 Periodical inspection and maintenance
11.3.1 In general
11.3.2 Inspection of tanks
11.4 Maintenance fire safety facilities
11.5 Waste
11.6 Documentation and document management
12 Change management
12.1 Introduction of changes (organizational and technical)
12.2 Reporting changes
12.3 Implementing consequences of changes
13 Termination and putting out of operation
References
Annex A: Additional recommendations for tank foundations
Annex B: Additional recommendations for tank constructions
Annex C: Standards for tank installations
Annex D: Distance tables from the codes of the Institute of Petroleum (IP) (ref. 44)
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1 Introduction
1.1 Amendments new directive compared to CPR 9-2/3
Compared to the directives CPR 9-2 and CPR 9-3, some amendments were made to this revised
directive, the most important of which are mentioned briefly hereinafter.
For installations for liquids of class 3 with a tank storage capacity under 150 m3, the directive
CPR 9-6 will apply. For tanks with a capacity under 150m3 for liquids of classes 1 and 2, this
PGS-29 can be used. The international tank construction standards are also applicable to the
smaller tanks. In consultation with the competent authority and the Fire Department, parts of this
directive can also be applied to these smaller tanks.
In this revised directive, the division into (fire) classes has been adjusted to the European
Directive 67/543/EEC [Ref. 41]. This adjustment does not have consequences in practice. The
terms K1, K2, and K3 have been abandoned; they are replaced by classes 1, 2, 3, and 4,
respectively, also used in the directive CPR 9-6. See Chapter 3, Definitions and terms, under
“Class” for this purpose.
In this revised directive, a distinction is made between the following four types of storage (see
Chapter 3, Definitions and terms):
1. tanks with a fixed roof;
2. tanks with a floating roof;
3. tanks with a fixed roof with an internal floating roof;
4. tanks with a supported geodesic roof, also with an internal floating roof.
Wherever possible, reference has been made to international standards and codes.
By the publication of this directive the directives CPR 9-2 and CPR 9-3 will be cancelled.
1.2 Starting points
The starting point is that storage tanks meet at least one of the existing international standards or
codes for tank construction of API 650 [Ref. 4], BS 2654 [Ref. 22], and DIN 4119 [Ref. 32] in
revisions as they were applicable at the time of construction, and in case of new construction NEN
EN 14015-1 [Ref. 70] (in as far as relating to atmospheric tanks). Also other Netherlands
directives, such as the “NRB” [Ref. 82] (“BoBo” guideline) and the “NeR” [Ref. 48] (containing
KWS 2000 [Ref. 46]), apply, but they are not part of this directive. The same applies to covenants.
When necessary or useful, reference is made to other standards and codes, for instance that of
NFPA and AI sheets.
The regulations (laws and Implementation Decrees) have direct effect and do not need to be
inserted in directives and licenses.
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2 Object, field of application, and use
2.1 Object of this directive
The object of this directive is in general reducing safety risks. In a more narrow sense, this
directive intends to be a clear reference framework for the business community as well as the
competent authority for the erection, use, preservation, and inspection of installations with vertical
tanks. This is mainly of importance, because undesired incidents can lead to serious accidents
within and outside the establishment and to serious pollution of air, soil, and water. The directive
is of importance to the government for the granting of licenses, to the business community for the
design of installations.
A second function of this directive is to contribute to the harmonization of safety requirements of
several license-granting agencies to different companies.
2.2 Field of application
2.2.1 In general
This directive is applicable to establishments with at least one vertical, cylindrical, aboveground
tank the floor of which rests on a foundation and in which flammable liquids of classes 1, 2, and 3
are stored under atmospheric pressure, and for substances of class 4 that are stored while heated.
Substances that are stored at a temperature equal to or higher than their flashpoint have to be
treated as a substance of class 1.
This directive is also, but with additional requirements, if necessary, applicable to flammable
liquids that also belong to another risk category.
For these flammable liquids that can, for instance, also be poisonous, harmful, corrosive, or
conducive to burning, other or additional requirements can also apply, which have to be laid down
per case in the environmental permits. Examples of these substances from practice are acrylic
nitrile and methanol (both poisonous).
The risk categories to be used are those as laid down in the Chemical Substances Act [Ref. 93]
and the European Directive 67/543/EEC [Ref. 41] and its amendments.
2.2.2 Exceptions for substances
This directive is consequently not applicable to:
- compressed gases and/or gases made liquid by refrigerating, for instance propane and butane;
- liquids of class 0. However, within class 0, there are liquids that have a vapor pressure (TVP)
of a maximum of 500 mbar when stored under atmospheric circumstances.
This directive can be applied to the following, at the discretion of the competent authority:
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- non-flammable liquids, such as watery solutions of inorganic substances, aerosols, foams, etc.;
- flammable liquids with a flashpoint of over 100oC that are not heated, or that are stored and
transferred while heated, provided that the temperature of the liquid remains at least 20oC
below the flashpoint;
- storage of liquids of class 3 as referred to in the directive CPR 9-6 [Ref. 29].
2.2.3 Exceptions for activities
The term “establishment” corresponds with the term “establishment” as used in the Environmental
Management Act [Ref. 92], and the Implementation Decrees belonging thereto (see Chapter 3:
Definitions and terms). Often there is question of complex establishments where also other
activities than tank storage and the transfer belonging thereto take place. Examples hereof are:
- storage in other tanks than those this directive relates to, such as tanks for the storage of gases
compressed to liquid, underground tanks, horizontal tanks, and smaller tanks;
- storage of vessels and mixed cargo;
- production processes;
- activities other directives apply to.
This directive basically only relates to the part of an establishment where the storage of liquids
and the activities directly related to it, such as transfer and transfer by pumps, take place.
In complex cases, doubts can arise about what directives or standards apply to what sections. In
those cases, consultation between the operator and the competent authority has to lead to
agreement.
The directive does not apply either to the transportation of flammable liquids that falls under
transportation regulations.
2.3 Use of this directive
This directive will be used in practice by the business community and license-granting agencies.
The regulations of this directive do not exclude the use of other systems, methods, or instruments
with equal or better quality, strength, fire resistance, effectiveness, durability, or safety, provided
that the equality has been proven to the competent authority and the systems, methods or
instruments suggested in deviation from this directive are suitable for the application suggested.
These deviations have to be approved by the competent authority.
The regulations of this directive do not have direct effect, but are only applicable if and in as far as
they have been included in environmental permits.
This directive is also applicable when changes to existing establishments are granted. The
competent authority has to take into account that in this situation, when using this directive,
several regulations cannot be applied or only in part. Of course this applies to the regulations for
new construction and regulations that affect the infrastructure and working method granted in the
past. In these cases it is up to the competent authority to judge what regulations can be included in
reason.
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3 Definitions and terms
1. Petroleum product
Product from a petroleum refinery.
Examples are naphtha, gasoline, kerosene, white spirit, diesel oil, domestic fuel oil, fuel oil. Also
catalytic cracked products of the refinery and natural gas condensate are considered petroleum
products.
2. Atmospheric storage
The storage is considered to be atmospheric if the absolute pressure above the liquid is under 1.06
bar during storage.
3. Control measure
Actions, programs, procedures of an organizational or administrative nature with the object to
perform the necessary acts to protect safety and the environment. Also called “measure”.
4. Flammable (liquid) substance
A liquid that is flammable itself or from which a flammable gas, flammable vapor, or flammable
mist can arise (EN-IEC 60079-10) [Ref. 39].
5. Fire-safety plan
Collection of all data on fire risks in a company or organization and on the measures and facilities
present to reduce these risks as much as possible.
6. Fire Department
The government’s fire department
Explanation:
If the subject is firefighting, Fire Department is understood to be the repressive service of the Fire
Department. If it concerns advice, the Fire Chief of the municipal or regional fire department or his
representative is meant.
7. Chemicals
Within the framework of this directive, chemicals are understood to be:
1. (petro)chemical products of petroleum products, which have been created by chemical
conversion or by thermal cracking.
2. flammable liquids of biochemical origin, for instance ethanol.
Inorganic chemicals in liquid form or dissolved in water or emulsified are consequently not
chemicals in the sense of this directive.
8. Vapor pressure
The absolute pressure in bar, determined in accordance with the standard NEN EN 12 [Ref. 65]
with the Reid device.
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9. Vapor return system
A system meant to catch vapors that would otherwise be released into the atmosphere on account
of displacement losses and to return them without processing to the tank from which one pumps.
10. Vapor processing system
A system meant to catch and process vapors that would otherwise be released into the atmosphere
on account of displacement losses (including breathing losses).
11. Diameter for tank distances
If the diameter (D) of a tank is used to indicate mutual distances between tanks, the diameter of
the largest tank in the tank farm containment area is meant, unless indicated otherwise.
12. Operator
The one who operates the establishment or who is liable for operating the establishment. Mostly
this is the holder of the environmental permit.
13. Explosive atmosphere
Explosive atmosphere as defined in NPR 7910-1 [Ref. 81].
14. Explosion range
The explosion range of a stored product is defined by the circumstances under which the product
has a vapor pressure (and vapor composition) at which the vapor-air mixture is explosive. This
range is between the lower and upper explosion limit.
Explanation:
The lower explosion limit is the lowest vapor concentration at which the vapor-air mixture can be ignited
as yet, after which this mixture burns down without energy supply from outside.
The upper explosion limit is the highest vapor concentration at which the vapor-air mixture can be ignited
as yet, after which this mixture burns down without energy supply from outside.
Below the lower explosion limit the mixture has too few, and above the explosion limit it has too many
flammable vapors to be able to keep it burning.
To determine explosion limits, see the “Chemiekaartenboek” of “TNO Arbeid” [Ref. 24] and the
Association Netherlands Chemical Industry (“VNCI”) 2003 [Ref. 89].
15. Foundation
The foundation the tank rests on, for instance risen foundation.
16. Geodesic roof
Self-supporting domed tank roof.
17. Danger zone
The area where flammable vapors can occur under normal circumstances. This area corresponds
with the term “danger zone” of the standard EN-IEC 60079-10 [Ref. 39] and NPR 7910-1:2001
[Ref. 81]. The area beyond it is a “non-danger zone”.
18. Installation
Permanent technical unit within which one or more activities take place and all other activities
directly connected to them that are technically related to the activities performed within this unit.
Explanation:
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An establishment can consequently consist of several installations: tank farm containment areas, offices,
plants, transfer areas, etc. are individual installations.
19. Establishment
Each activity undertaken by humans commercially or with a scope as if it were commercial, which
is usually performed within certain boundaries.
20. Class
This directive mentions class 0, class 1, class 2, class 3, and class 4.
Table 3.1 provides the division into classes.
Table 3.1: Division into classes with regard to fire hazard
Class Flashpoint limits Examples
Class 0 Flashpoint (FP)<0oC
Boiling point<35oC
substances of class 0 are not stored
under atmospheric circumstances
Class 1 FP<21oC, but not
falling in class 0
gasoline, benzene, toluene,
petroleum ether
Class 2 21oC≤FP≤55
oC kerosene, white spirit, solvent naphtha
Class 3 55oC<FP<100
oC diesel oil, HBO I, HBO II
Class 4 FP≥100oC fuel oil,
lubricating oil
21. Coupler
Piece of pipe to make a (temporary) connection between two parts of a pipe.
22. Crest lines
Horizontal lines on the interior and exterior of the horizontal part (the crest) of a dike. An interior
crest line is on the interior of the tank farm containment area, an exterior crest line is on the
exterior of the tank farm containment area.
23. L.O.D. Lines of defense, safety measure
The available technical and/or organizational measure to control the risks of serious accidents.
This can be focused on a containment system (specific) or apply to the entire establishment
(generic).
24. Measure
See control measure
25. Emergency plan
A description of measures and facilities an establishment has prepared to minimize and fight
effects of (undesired) calamities.
26. Storage temperature
The maximum temperature that can occur in the liquid stored during the normal business
operations.
27. Collecting capacity
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Collecting capacity of the tank farm containment area is the capacity of the tank farm containment
area under the lowest height of the surrounding dike or wall, reduced by the volume inside that is
absorbed by other (smaller) tanks, risen foundations, dividing dikes, and appurtenances.
28. Product pipe
All pipes that are connected with the tank content, such as suction pipes and filling pipes.
29. Dike
A liquid-barrier wall around a tank farm containment area that can provide for collection of
product from the storage tank(s) and of a possible amount of (fire)water. A dike can consist of a
wall of earth/sand/clay, a steel or concrete wall, or another (liquid-barrier) construction. A dike
can be the partition between a tank farm containment area and the surroundings and between a
tank farm containment area and an adjacent tank farm containment area.
30. Compounds Parts of a tank farm containment area separated from each other by one or more dividing dikes
(compounds).
31. Disaster or serious accident
An incident:
- that has caused a serious disturbance of public safety, by which life and health of many
persons are seriously threatened or have been seriously harmed, and;
- for which a coordinated effort of services and organizations of various disciplines is required
to remove the threat or limit the harmful effects.
32. Fracture joint
A weak joint between tank wall and tank roof, created intentionally, meant to yield first in case of
fire or explosion.
33. Tank
In the sense of this directive, a tank is an aboveground, vertical, cylindrical container the tank
floor of which rests on a foundation. Tanks have the function to provide for storage capacity for
transportation, delivery, or commercial purposes, or as interim storage in a production process. No
new substances are produced in the tanks with chemical reactions. However, by mixing, stirring,
or heating, (mixtures of) substances can be brought up to delivery specification or mixtures can be
separated by sedimentation or stratification in tanks.
Within the framework of the field of application of this directive, four types of tanks can be
distinguished.
1. tanks with a fixed roof (tapered or domed), whether or not with a support construction for the
roofing sheets;
2. external floating roof tanks;
3. tanks with a fixed roof as referred to in 1, and provided with an internal floating roof (internal
floating roof tanks) and provided with:
- open vents or
- pressure vacuum valves;
4. tanks with a self-supporting domed roof, based on a geodesic design, whether or not provided
with an internal floating roof.
34. Group of small tanks
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A group of small tanks as referred to in IP code, Volume 19.
35. Tank farm containment area
A part of the site surrounding a storage tank that provides for collection of product or (fire)water
by sunken installation or a surrounding closed wall (dike).
36. Foundation
The foundation of the tank.
37. Site boundary
The boundaries of the establishment as referred to in the definition of the term establishment.
Explanation:
On the side of the land, this is usually fencing. On the side of the water there is often no other barrier than
the water itself.
38. Dividing dike
A facility dividing the surface of the tank farm containment area, with the object to prevent liquid
from spreading over the total surface of the tank farm containment area in case of a minor leak. A
dividing dike can consist of a wall of earth/sand/clay, a steel or concrete wall, or another (liquid-
barrier) construction. Also called: dividing dam.
39. Vertical cylindrical tank
A vertical cylindrical vessel the tank floor of which rests on a foundation.
40. Flashpoint
The temperature of the liquid at which a flammable mixture can be created (flashpoint) with air,
just above the liquid.
The flashpoint up to 55oC is determined in accordance with the Abel-Pensky method, described in
NEN EN ISO 13736 [Ref. 69].
The flashpoint over 55oC is determined in accordance with the Pensky-Martens method, described
in NEN EN ISO 2719 [Ref. 66].
The flashpoint of substances and/or mixtures stored while heated has to be determined based on
the ASTM D3941-90(2001) [Ref. 15]. Determining whether the fire is self-sustained can be done
by means of the ASTM D4206-96(2001) [Ref. 16].
Explanation:
If it concerns a mixture of substances with a changing composition, one has to take the flashpoint of the
substance with the lowest flashpoint that constitutes at least 10% (volume) or more of the mixture at any
time.
41. Liquid-proof facility
A facility aimed at effect that guarantees that – subject to the condition of efficient maintenance
and adequate inspection – no liquid can get to the side of this facility that does not contain liquid.
42. Liquid-barrier facility
A facility that is not liquid-proof, which is capable of temporarily barring substances released for
so long that they can be cleaned up before they can penetrate into the soil.
43. Facility
Technical equipment meant to:
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- meet the operational objectives;
- improve and guarantee safety and protection of the environment.
44. WBDBO
Fire transfer resistance and fire spread resistance in minutes. See NEN 6068 [Ref. 64].
45. Zone
Zone 0: an area within which an explosive atmosphere is present continuously or during long
periods of time. See NPR 7910-1:2001 [Ref. 81]
Zone 1: an area within which the chance of presence of an explosive atmosphere is
substantial under normal operations. See NPR 7910-1:2001 [Ref. 81].
Zone 2: an area within which the chance of presence of an explosive atmosphere is small
under normal operations and within which such an atmosphere, if present, will only
exist for a brief period of time. See NPR 7910-1:2001 [Ref. 81].
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4 Tank storage, activities, and design
This directive specifies the facilities and control measures required that are applicable to
establishments where storage of flammable liquids in aboveground, cylindrical storage tanks takes
place.
Regulations that only apply to installations with liquids of classes 1 and 2 have explicitly been
indicated.
Specific control measures have been indicated with the facilities in question. The general control
measures have been described in Chapter 8 through 13 of this directive.
4.1 Activity
In the establishment, activities can take place that consist of storage and transfer of liquid
chemicals and/or mineral oil products in aboveground storage tanks, tank trucks, and ships. The
activities that take place in an establishment can be subdivided into:
- storage of products, liquid waste, waste water, and ballast water of ships;
- loading and unloading of ships, tank trucks, train tank wagons, and tanks;
- transfer from ship to ship;
- transfer of products by pumping through external pipelines;
- degassing and cleaning of tanks and pipelines;
- butanization of products;
- filtering, mixing, and homogenization of products;
- adding of additives;
- heating of products;
- washing of products.
The establishment can dispose of the following buildings and facilities:
- tank park;
- tank farm containment areas;
- piers;
- loading and unloading area for tank trucks;
- pump platforms;
- pipelines;
- hoses;
- vapor processing systems;
- buildings, including:
offices;
mobile work and storage units;
warehouse buildings;
workshops;
service buildings;
security booth;
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group of huts/sheds;
sample rooms;
low-high voltage areas;
gas bottle storage space;
gas reception and reduction station;
boiler houses;
transformer buildings;
- fire department’s training area;
- waste collection areas;
- emergency power facilities;
- compressed air system;
- drinking water facility;
- sewage system;
- lighting;
- roads.
4.2 Design of the site
Demarcation of the site
1. The site where the establishment is located has to be surrounded at any rate on the land sides
by an efficient fence. The construction and height hereof has to be such that access to the site
other than through the entrances is discouraged.
Entrances
2. In connection with the accessibility of the installations for emergency services, the
establishment has to be accessible through at least two entrances located as far apart as
possible. Depending on the local situation and the possibilities, this may be deviated from in
consultation with the Fire Department. The entrances in the fence have to be kept closed as
much as possible. Open entrances have to be supervised at all times.
Road plan
3. The road plan has to be drawn up and approved in consultation with the competent authority
and the Fire Department.
Explanation:
The road plan supports a traffic circulation plan that adequately separates the various forms of
transportation on the site and counters unnecessary transportation movement.
4. The road plan has to be designed in such a manner that at all times the installations, tank farm
containment areas, and buildings can be reached without obstruction by at least two separate
roads. Tank farm containment areas have to be adjacent to roads that are suitable for driving
on at least two sides. Additional requirements are found in the municipal building ordinance.
Lighting of the site
5. There has to be lighting on the site that facilitates proper orientation, normal activities during
the night, and security.
Landscaping
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6. No fire-hazardous trees or bushes are to be found on the storage site of the establishment
within a distance of 15 m from a tank farm containment area or loading or unloading area for
liquids.
7. The plants cannot obstruct firefighting.
8. Except on undeveloped land, weeds and grass will be kept short. Dry wood, leaves, and cut
weeds or grass have to be removed immediately. The use of weed killers is only permitted if
this does not constitute a fire hazard.
Maintenance
9. All roads, dikes, fencing, buildings, and other facilities on the site of the establishment have to
be in a good state of repair.
10. The site of the establishment have to be kept clean.
11. Materials that are not used and waste have to be removed or stored on parts of the site
designated for this purpose, if possible in special containers.
4.3 Mutual distances
The fire-safety requirements of this directive are based for the larger part on the IP code, Volume
19.
12. In new installations and in case of changes to installations, the minimum distances between
the various parts of the installation have to comply with the codes of the Institute of Petroleum
[Ref. 44].
Explanation:
As an illustration, according to the IP codes for liquids of classes 1, 2, and 3, the distances
between parts of installations are listed in Annex D. They do not apply to substances such as
bitumen and only if the tank farm containment areas are provided with additional
requirements, such as access roads over the dike. This table serves as an illustration. For
accurate interpretation of the distance rules one has to consult the IP codes.
The distances in the IP codes are recommendations. Designers have to use them as a guideline.
The competent authority may deviate from the distances recommended, provided that safety is
adequately guaranteed by provisions and measures.
13. Buildings with vital functions, the proper functioning of which also has to be ensured in the
event of a fire, such as transformer buildings and storage spaces for firefighting materials,
should not be located in a danger zone. If these buildings contain heating installations that
suck in outside air, the places where this combustion air is sucked in have to be located on the
side facing away from a danger zone.
14. The distance of filling spaces, filling areas, pump houses, and storage spaces for packed
products of classes 1 and 2 has to be at least 15 m to:
- storage spaces for storage of vessels of products of classes 1 and 2;
- the site boundary;
- the interior crest line of a tank farm containment area;
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- a building in which one can work with fire or in which open fire can be present, such as
workshops and welding spaces.
15. Operating buildings in which open fires or ignition sources are present, such as workshops for
maintenance, service buildings, and boiler houses, have to be located in a non-danger zone.
16. Heating boilers installed in the outside air have to be located in a non-danger zone.
17. In all cases, the combustion air for the fires has to be sucked in on the side facing away from a
danger zone; the doors of a boiler house have to be installed in the side of facing away from a
danger zone.
18. Office buildings have to be located in a non-danger zone. Openings through which outside air
is sucked in for heating installations have to be located on the side facing away from a danger
zone. These buildings have to consist as much as possible of inflammable building materials.
Preferably, the buildings have to be located in such a manner that access for the public is
provided without passing the exterior fence.
19. The distances referred to in this Chapter may be deviated from, provided that it has been
proven by a risk analysis approved by the license-granting agencies that smaller distances can
suffice.
4.4 Sewage system and drainage
20. In consultation with the competent organizations, one has to see to effective facilities for the
discharge of drainage and rainwater and other possibly polluted water from tank farm
containment areas, piping routes, pump areas, loading and unloading areas and the like.
Explanation:
a. Discharge from tank farm containment areas: see paragraphs 5.6 and 5.7.
The discharge of drainage and rainwater from tank farm containment areas in surface water or in a
public sewage system can only be done through efficient oil or liquid separators. Underground,
closed parts of these sewer pipes have to be kept filled with water in order to prevent risk of
explosion.
b. Discharge from other parts of the site belonging to the tank installation:
- Drainage and rainwater coming from places where product leaks can be expected (for
instance pump areas and piping routes) has to be discharged through an efficient oil or
liquid separator before discharge in the surface water or public sewers takes place, in
conformity with the license in pursuance of the Pollution of Surface Waters Act or the
Environmental Management Act.
- Risk of explosion in underground sewer pipes can be prevented by keeping them filled with
water.
- All other underground sewer pipes have to be installed with a gradient.
- Drainage, rainwater, and domestic waste water coming from places where no product leaks
are expected can be discharged through a separate sewage system, in conformity with the
license in pursuance of the Pollution of Surface Waters Act or the Environmental
Management Act.
4.5 Electrical installations and grounding
4.5.1 Electrical installation
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21. The entire electrical installation has to comply with the regulations of the standards:
- EN NEN 500110 [Ref. 40];
- NEN 3140 [Ref. 54].
Explanation:
In a danger zone the electrical installation also has to comply with the statutory regulations arising
from the European ATEX directives concerning “Equipment and safety systems on locations where
there may be a risk of explosion” [Ref. 18], and “Protection of workers who are at risk due to an
explosive atmosphere” [Ref. 19]. These directives have been contained in Netherlands legislation in
the Dangerous Equipment Act [Ref. 94] and the Explosion-safe Equipment Decree [Ref. 20].
22. It has to be possible to shut down the electrical installation within a danger zone in all poles
and phases by means of one or more switches that are placed in a non-danger zone.
23. On or near each switch, the destination and the switch positions have to be clearly indicated.
4.5.2 Grounding
24. A storage tank has to be grounded in conformity with the standards NEN 1010 [Ref. 49] and
NEN 1014 [Ref. 50].
25. Installation of the grounding and the testing hereof has to take place in conformity with NEN
1014 [Ref. 50] by an accepted expert, approved by an accredited organization. The expert has
to provide a certificate of the grounding installed.
26. The grounding has to be tested once every five years by an expert measuring leakage
resistance, which expert has been accepted by the competent authority.
27. In case of a tank diameter exceeding 6 m at least two grounding cams have to be present; the
mutual distance over the periphery of the tank wall cannot be more than 20 m.
28. Permanently conductive stainless steel strips with a minimum width of 30 mm have to be
affixed to internal or external floating roof tanks between the roof and the tank wall. The
number of strips depends on the installed type of seal. The minimum distance between the
strips is 2 m for vapor mounted seals and liquid mounted seals. In case of mechanical shoe
seals, one strip per shoe plate has to be affixed.
Explanation:
When a rolling ladder is present, the cable can be connected between the ladder construction and the
access platform (to bridge the hinges) on the one side and the ladder construction and the rails (to
bridge the wheels) on the other side.
29. For internal floating roof tanks, grounding cables have to be affixed between the tank and the
floating roof in conformity with NEN-EN 14015-1 [Ref. 70], Annex C. For external floating
roofs, Annex D of NEN-EN 14015-1 applies.
4.5.3 Measures against static electricity
30. When transferring products that can be charged electrostatically according to ASTM-D-4865-
96 [Ref. 17] and NFPA 77 [Ref. 78] by pumping, the velocity in the pipelines has to be limited
to 1 m/s in the following cases:
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- if various products (of the same class) are pumped through the pipe, separated by water;
- if a product is displaced in the pipe by water;
- if one pumps in an empty or almost empty tank;
- if one can expect the product to have been polluted by water, air, or solid particles.
This limited velocity has to be kept up until the entire pipe contains only one liquid, but at
least for half an hour. A higher filling velocity is only permitted after one has made sure that
aforementioned cases do not present themselves. In the event of an empty or almost empty
tank, the limited velocity has to be kept up until the liquid level in the tank is at least 0.50 m
above the inlet opening.
4.6 Danger zone design
Measures for explosive atmospheres
The directive NPR 7910-1 [Ref. 81] sets rules for the design of workplaces where an explosive
atmosphere may occur.
Explanation:
The Working Conditions Decree obligates employers to evaluate the risks in connection with explosive
atmospheres and the special risks that may arise from same within the framework of the risk inventory and
risk evaluation before the start of the work and upon each important change, expansion, or alteration of the
workplace, the work equipment, or the work process as a whole. This evaluation has to be recorded in
writing in an explosion safety document.
If the evaluation shows that there can be an explosive atmosphere, areas of where an explosive
atmosphere can be are divided into danger zones as referred to in Annex I of the NPR 7910 [Ref.
81].
Furthermore, the Working Conditions Decree obligates employers to take general, specific, and
special measures related to explosive atmospheres or the risk hereof.
4.7 Hydrogen sulfide
31. For the storage of substances that can contain hydrogen sulfide (H2S), an H2S policy has to be
in place. This policy has to contain regulations concerning:
- design starting points, for instance application of closed drains, minimizing holdups, safe
deaeration;
- H2S detection systems, both permanent detection systems (for instance in pump-pads) and
personal monitoring systems;
- procedures, for instance:
the identification of H2S containing equipment;
opening of H2S containing equipment;
sampling;
pyrophoric ferric sulfide;
safe drainage;
- emergency instruction regarding the release of an H2S cloud;
- personal means of protection, the application, instruction, training, and maintenance;
- first aid in case of accidents with or exposure to H2S.
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5 Tank farm containment areas
5.1 Permitted activities in the tank farm containment area
32. A tank farm containment area cannot contain any form of storage than tank storage, except for
collection of rainwater in an open drainage system.
33. No materials can be stored or present nor can installations be found in the tank farm
containment area, other than tanks with appurtenances, pipes, and transportation pumps, if
any, unless and as long as these materials are necessary in the tank farm containment area for
maintenance and/or repairs.
34. Maintenance and or repairs can only be performed in the tank farm containment area after a
work permit has been granted for this purpose.
5.2 Minimum distances within the tank farm containment area
35. If tanks with fixed roofs and tanks with floating roofs have been installed in one containment
area, the provisions for tanks with fixed roofs will apply to all tanks in that tank farm
containment area, without prejudice to the specific provisions for floating roof tanks.
36. If a storage tank for products of class 3 is placed in a tank farm containment area that also
contains storage tanks for products of classes 1 or 2, the distances and the rules for the storage
of products of classes 1 and 2 will apply to the entire tank farm containment area.
5.3 Collecting capacity of the tank farm containment area
The collecting capacity of the tank farm containment area has to equal at least the content of the
largest tank augmented by the larger of the following two volumes:
- 10% of the volume of the other tanks in this tank farm containment area;
- the volume of firewater that can be brought into the tank farm containment area in one hour,
according to the capacity required in the license.
5.4 Construction of the tank farm containment area
5.4.1 Tank farm containment area floor
37. The tank farm containment area floor has to be above the highest groundwater level.
5.4.2 Dikes
Dike height
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38. The height of the dike is determined by the necessary collecting capacity of the tank farm
containment area, augmented by 0.25 m for possibly occurring gusts of wind, augmented by
the maximum setting of the dike to be expected locally until the next height inspection.
Explanation:
So when determining the height, one does not have to take into account a storm surge arising when a
tank collapses.
In order to limit the polluted surface and evaporation of pools and thermal radiation from a burning
pool in case of small leakage or spillage, it is of importance to keep the liquid surface within a tank
farm containment area limited by compartmentalizing the tank farm containment area by means of
dividing dikes.
For the capacity of the compounds and the height and construction of the dividing dikes, no regulations
are given. Of course, dividing dikes have to meet the objects set for same.
Liquid-barrier
39. The side of the dike at the tank farm containment area and the tank farm containment area
floor have to constitute a liquid-barrier.
40. The complex of containment area floor and dike has to be in conformity with the Netherlands
Soil Protection Guidelines (“NRB”) [Ref. 82].
Strength
41. The dike has to be constructed so strong and stable that it can resist the maximum liquid
pressure to be expected for quite some time. During the construction one has to take into
account the load-bearing capacity of the subsoil, adjacent roads and embankments, ducts, and
dike passages and settings, if any.
Fire resistance
42. The fire resistance of the dike has to be adjusted to the maximum scenario to be expected.
Inspection and maintenance
43. Dikes have to be inspected and maintained so often that the minimum height and liquid-barrier
remain guaranteed.
44. Damage found has to be repaired immediately.
45. Turfs of dikes have to be kept short.
5.4.3 Ducts
46. Ducts of pipes through dikes have to be avoided as much as possible.
47. Ducts through a dike have to be a liquid-barrier, fire resistant, resistant to the maximum
hydrostatic pressure to be expected and resistant to the substances stored. Ducts have to be
adequately strong and flexible to be able to absorb expected setting of pipes and dikes.
5.4.4 Access to the tank farm containment area
48. Tank farm containment area floor and dikes have to be protected in such a manner, for
instance by means of steps and accesses and crossings and walkways, that damage in case of
repeated access for inspection, sampling, and loading/unloading actions is prevented.
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Explanation:
For the access to the tank farm containment area with vehicles and materials for maintenance, one may
choose from the following options:
- preferably a crossing over the dike;
- a passage construction through the dike;
- the temporary excavation of part of the dike.
49. A crossing over the dike has to be adequate solid for the transportation to be expected and
leave the primary function of the dike intact. The crossing has to be closed for traffic, unless a
work permit has been granted for the use.
50. A passage construction through the dike has to meet the same requirements of solidity, height,
liquid-barrier and fire resistance as the dike. The construction has to be closed, unless a work
permit has been granted for the use. The maximum capacity present in the storage tanks in the
tank farm containment area has to be adjusted to the remaining collecting capacity in the tank
farm containment area before the opening of the passage construction. After use, the
construction has to be closed in such a manner that the requirements for the dike are met
again.
51. When part of the dike is temporarily excavated, the maximum capacity present of the storage
tanks in the tank farm containment area has to be adjusted to the remaining collecting capacity
in the tank farm containment area before the excavation. After the activities, the dike has to be
restored in such a manner that the excavated part and the connection to the non-excavated part
of the dike meet the original requirements. A work permit has to be issued for excavating the
dike.
5.5 Sewage system
52. Each tank farm containment area or compound has to be provided with a drainage and sewage
system that works independently from the sewage system of other tank farm containment
area(s) and/or tank farm containment area compound(s).
53. The shut-off valve meant for controlled drainage of water from the tank farm containment area
has to be affixed outside the tank farm containment area and be kept closed. The shut-off
valve can only be open during controlled drainage of water. The position of the shut-off valve
has to be visible on the outside. The sewage system has to be equipped with a facility that
facilitates inspection of possible pollution of the water to be drained at all times.
Explanation:
Controlled drainage of rainwater from the tank farm containment area can also take place by means of
pumps. Automatic switching of the pumps is not permitted (manual control).
54. The duct of the sewer pipe through the dike has to be fire resistant, resistant to the maximum
hydrostatic pressure to be expected, and resistant to the substances stored.
55. The sewers, the sewer pipe and the duct of the pipe through the dike cannot affect the liquid-
barrier of the tank farm containment area floor and the dike.
56. The capacity of the sewage system has to be adjusted to the maximum amount of rainwater to
be expected.
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57. The discharge of drainage and rainwater from tank farm containment areas into the surface
water or a public sewage system can only take place through efficient oil separators or liquid
separators.
5.6 Drainage of firewater
58. Each tank farm containment area should have a facility enabling the fire-safe drainage of
firewater. This facility has to be installed in such a manner that undesired transfer of the
firewater present in the tank farm containment area is not possible.
59. When a tank farm containment area is divided into compounds, each compound has to be
equipped with its own drainage facility.
60. If a power point or manual operation for the drainage of firewater is used, this power point or
this manual operation has to be outside the thermal radiation contour of 3 kW/m2.
5.7 Product pump in the tank farm containment area
61. In certain cases the competent authority may permit that a pump for product transportation is
set up in the tank farm containment area near the storage tank. This pump then has to meet the
following requirements:
- the electric motor of the pump cannot touch the surface of the liquid in the tank farm
containment area on account of an incident with a storage tank;
- if the mechanical part of the pump is of a type with which, when the source of power fails, the
flow of liquid can return through the pump body and lead to an increased risk, this pump has
to be equipped with a non-return valve on the outlet side;
- the pump has to stand on a liquid-tight concrete floor.
62. The electric motor of the pump has to meet the following safety requirements:
- electrical installation made in conformity with Eexd CT4;
- maximum temperature of the electric motor <135oC;
- temperature control on the electric motor by means of 6 times PTC;
- standstill heating on the electric motor to prevent condensation.
63. The mechanical part of the pump:
- has to be protected against too high temperature by temperature control on the bearings and
the housing;
- has to be equipped with gasket leak detection, for instance by a nitrogen flush on the double
mechanical seal;
- has to be equipped with flow control on the product pipe.
5.8 Pipes and shut-off valves in the tank farm containment area
Product pipes and shut-off valves that are in the tank farm containment area have to meet what is
referred to in paragraph 7.4. Vapor return pipes and their protections have to meet what is
referred to in paragraph 7.1.
64. The number of pipes connected to the storage tank has to be kept as small as possible.
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65. Joints (flanged joints, flexible couplings, and bellows) have to be avoided as much as possible.
The use of hoses for product transportation in the tank farm containment area is not permitted.
66. Shut-off valves in a tank farm containment area meant for transportation of liquids of classes 1
and 2 have to be fire-safe (at least the code ASME B16.5 [Ref. 11]) or similar. The shut-off
valves have to be equipped with product-proof and fire-safe gaskets. On the outside it has to
be clearly visible whether a shut-off valve is open or closed.
67. Pipes and their construction for fire-safety systems have to be equipped with passive
protection, for instance by a foaming coating.
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6 Storage tanks
6.1 General requirements
68. Tanks to be newly built have to meet the European standard NEN EN 14015-1 [Ref. 70]. For
deviation from the above standard, approval is required from an organization accepted by the
competent authority.
Explanation:
Apart from the environmental permit, the tank installations also have to meet the Rules for pressure
appliances. According to these rules, an independent organization has to issue a certificate of
investigation and testing (“BOB”) in case of new construction.
69. When evaluating whether existing tanks are still suitable to be able to fulfill their primary
function – the storage of a product – (“Fit-for-Purpose” analyses), the degradation limits as
referred to in the EEMUA publication No. 159 [Ref. 34] have to be followed.
70. Reconstruction, moving, adjustment, or repair of an existing tank has to be in conformity with:
- the code API 653 [Ref. 5], if the tank has been designed in accordance with the code API 650
[Ref. 4];
- the EEMUA publication No. 159 [Ref. 34], if the tank has been designed in accordance with
the standard BS 2654 [Ref. 22].
71. The once chosen standard or code has to be used consistently. It is not permitted to use various
standards or codes for a tank and to select the most favorable regulations from same.
72. The welding method has to be in conformity with the tank construction standard concerned or
EN 288-3 [Ref. 37], and has to be approved by a controlling organization recognized by the
competent authority before welding is begun. The welding has to be carried out in conformity
with the approved welding method and has to be done by previously qualified welders.
6.1.1 Construction
Annex A to this directive contains recommendations for the foundation. There are no other
standards or codes for it.
Annex B to this directive contains additional recommendations for the construction of tanks that
supplement the codes referred to in paragraph 6.1.
6.1.2 Calculation bases
73. The dimensioning basis of a new storage tank has to be in conformity with the standard NEN
EN 14015-1 [Ref. 70], as soon as it has been ratified by the government. Pending this
ratification, newly built tanks have to meet the standards or codes API 650 [Ref. 4], BS 2654
[Ref. 22], or DIN 4119 [Ref. 32]. The construction drawings with the calculations belonging
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thereto have to be submitted for evaluation to an organization accepted by the competent
authority. Roofs supported by columns cannot be used.
74. To determine the wind load in accordance with the draft standard concerned, the wind velocity
is fixed at 45 m/s for tanks to be set up in the Netherlands.
75. When calamities cause excessive excess pressure, the tank construction has to be such that the
connection of the wall to the floor cannot yield and that the tank wall also remains intact.
Explanation:
This has to be met by giving the top side of the tank a fracture joint. If a fracture joint cannot be
realized (see also API 650, Annex F [Ref. 4], and BS 2654 [Ref. 22], Annex F) and NEN EN 14015-1
Annex K [Ref. 70], the following measures have to be taken:
- Calculations have to prove that the connecting welds of the tank floor/tank wall are stronger than the
connecting welds between tank wall and tank roof, or:
- One or more emergency vents have to be applied, the necessary capacity of which has been
determined in accordance with the code API 2000, section 4.3.3.2 [Ref. 7].
- In consultation with the competent authority, it has to be determined whether, in addition to the
emergency vent(s), the tank has to be operated with an inert gas cover.
- For tanks with a diameter < 12.5 m the directives of the EEMUA publication No. 180 can be
followed as an alternative [Ref. 35].
The joint roof plate–tank wall cannot be too strong, the roof slope cannot exceed 1:5, and the fillet
welds cannot exceed 5 mm. In case of modifications to the tank roof, this situation also has to be
maintained.
6.2 Access to tank roofs
76. The access to tank roofs has to meet NEN 14015-1 [Ref. 70].
77. Roofs of tanks being part of a group in one tank farm containment area can also be accessible
by the footbridges mutually connecting these tanks. The last tank in a row, seen from the
rising spiral staircase then has to be equipped with an escape (cage) ladder. Depending on the
diameter of the tank or the setup in a tank farm containment area, fixed stairs are required
additionally, the slope angle of which cannot be more than 45 degrees with a step width of at
least 0.60 m.
78. External floating roof tanks can never be connected with each other by footbridges.
6.3 Tank equipment
6.3.1 Aerating a tank with a fixed roof
79. A tank with a fixed roof has to be protected against impermissible under-pressure and excess
pressure. For the storage of substances of classes 1 and 2 and heated liquids that have to be
treated as substances of these classes (see 2.2.1), a pressure/vacuum valve has to be applied of
such design that the following requirements are met:
- the adjustment pressures by which the valve opens have to be chosen in such a manner that
the pressure in the tank cannot go beyond the maximum or the minimum design pressure,
also in case of maximum transfer;
- raining in and freezing over cannot occur;
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- no flame arrestors and detonation protections may be affixed to the pressure/vacuum
valve(s), if the effluent opening is in connection with the outside air. If the effluent takes
place to a vapor return installation or vapor reclaim installation, flame arrestors and
detonation protections can only be installed in conformity with the design requirements of
the system.
In case of products of class 3, an open connection to the atmosphere is permitted. This open
connection has to be provided with bird-proof grille or wire netting. One has to take into
account the flow-through limit of this grille or wire netting when calculating the minimum
required flow-through capacity of the open connection.
6.3.2 Aerating a tank with a floating roof
Internal floating roof tanks
80. In case of an internal floating roof tank, vents have to be made in conformity with Annex
C.3.4.1 of the standard NEN EN 14015-1 [Ref. 70]. Under conditions in which open vents are
not desired in accordance with this standard, the tanks need to have pressure and vacuum
valves, the capacity of which has to be determined in accordance with the API 2000 [Ref. 7].
If calculations prove that an explosive mixture can regularly exist in the vapor space above the
internal floating roof, pressure and vacuum valves also have to be applied.
Explanation:
When applying internal floating roofs with a low emission limit and with many transfers (fillings and
emptyings in brief periods of time), it can be dangerous to use open vents, as the vapor space is then
regularly filled with explosive mixtures (neither saturated nor non-saturated vapor).
External floating roof tanks
81. External floating roof tanks the products of which contain light fractions that can evaporate
(for instance non-stabilized crude oil) need to have pressure valves to prevent gas bubbles
from accumulating under the membrane of single cover roofs or need to have systems by
which the gas can be led to the space between the primary and secondary seal through ducts.
82. If a mechanical shoe seal has been affixed in the crack between the floating roof and the tank
wall, rim vents also need to have been affixed the adjusting pressure of which has been chosen
in such a manner that the seal material cannot yield.
6.3.3 Seal materials and workable ranges of seals
83. Seals of internal and external floating roofs have to be made of materials in conformity with
the EEMUA 159 directive [Ref. 34]. Moreover, the workable range of the seal needs to have
been chosen in such a manner that it complies with Annex D.3 of the EEMUA 159 directive
[Ref. 34]. The seals have to meet the maximum slits that can occur between the seal and the
tank wall, also indicated in this directive.
6.3.4 Shut-off valves
84. Shut-off valves have to be closed when in rest and placed as close as possible to the tank.
6.3.5 Anchors
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85. Anchors have to be at least of a 4.6 quality with a material strength in conformity with DIN
267 Teil 3 [Ref. 31].
86. In case of gluing of the anchoring, the available anchor strength has to be inspected.
6.3.6 High-level alert and overfill protection
87. Tanks have to be equipped with:
a. a high-level alert that raises an alarm on location and/or in the control room, before the
highest permitted liquid level in the tank is reached, so that measures can be taken to
reduce the pump capacity or to stop the transfer by pumps, and;
b. a physically independent instrumental overfill protection that causes the supply to the
tank to stop when the highest permitted liquid level in the tank is reached.
The reliability of the instruments and protections has to be in proportion to the safety risk. One
has to use a methodology that proves and documents the relation between the risks,
determined by safety studies, and the (reliability of the) measures (instruments and
protections).
Examples of methodologies:
- SIL methodology in which, depending on the desired risk reduction, requirements are made
for the choice and maintenance frequency/type of the necessary regulations and protections;
(NEN EN 61511/61508)
- safety layer methodology, for instance LOPA;
- company policy linking the risk to the measure; for instance, for a scenario with a risk
valuation X, at least two independent LODs have to be used to control the risk.
Explanation:
If in case of unloading of ships the second protection is not possible from a technical point of view, it
can be refrained from in consultation with the competent authority or an alternative solution with an
acceptable level of protection can be agreed on.
Physically independent is understood to be:
- independent of level measurement
- individual steering signal
Overfill protection is understood to be:
- every system that causes the supply to the tank to stop automatically without intervention of an
operator.
6.4 Non-destructive examination of welds after new construction of tanks
88. Examining welds with non-destructive detection techniques has to be performed at least in
conformity with the requirements of the BS 2654 [Ref. 22], irrespective of what code/standard
has been used for the design of the tank (see paragraph 6.1).
Explanation:
There are differences between the codes with regard to the minimum requirements of (the amount of)
non-destructive examination of welds in tanks. In order to level these differences, one has to use the
requirements of the BS 2654, so that no distinction is made between tanks on one and the same
location. Moreover, the minimum requirements of the BS 2654 with regard to the acceptance of the
competent authority are normative.
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7 Other facilities
7.1 Vapor processing installation and/or vapor return system
89. The design of a vapor return system and/or vapor processing installation has to be
substantiated with a safety study. The design and safety study need to be approved by the
competent authority.
Explanation:
It is preferable that in case of vapor processing vapors are reclaimed or converted into electrical energy
or heat for energetic application.
It is crucial that one works in sections that, depending on the nature of the substances and the direction
of the flow, are separated by one-sided or double-sided functioning detonation protection/baffle plate
grilles.
7.2 Pump-pads
The object of a pump-pad is to have a collection of product pumps, shut-off valves, and product
pipes/hoses, where connections can be made between the tanks, between tanks and
loading/unloading areas, and between tanks and piers.
90. The pump-pad has to be made liquid-proof and cannot have a direct connection with a tank
farm containment area or sunken pipe track. Pipe ducts through the wall of the pump-pad have
to be avoided as much as possible. If it is not possible in another way, the pipe ducts have to
be made liquid-proof. A liquid barrier pump-pad with ducts is acceptable, provided that a
control system has been attached to it, approved by the competent authority.
Explanation:
As with all other activities, the soil protection of the tank farm containment area has to meet the
Netherlands Soil Protection Guidelines for business premises [Ref. 82].
91. The pump-pad has to be designed in such a manner that switching of product flows with hoses
is prevented as much as possible.
92. If possible, the setup location of the product pump is chosen in such a manner that the electric
drive of the product pump cannot touch the liquid in case of leakage, if any, in the pump-pad.
93. A facility has to be present in the pump-pad to discharge the rainwater collected in the pump-
pad. This facility has to meet at least the same requirements as set for the discharge of
rainwater from a tank farm containment area.
7.3 Transfer
7.3.1 General requirements
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94. Transfer activities can only take place in loading and unloading areas specifically fitted up for
this purpose.
95. During loading and unloading, instructions have to be available for safe loading and
unloading.
95a During loading and unloading, all protections have to be operational.
95b Protections cannot be bridged, unless this is necessary for safety reasons.
There has to be a protocol/procedure available, guaranteeing the following:
- the tasks, powers and responsibilities with regard to the bridging of protections;
- the registration;
- the recognizability of bridging by means of signs.
96. The connections of the product pipes to the loading and unloading area have to be designed
and/or marked in such a manner that mixing up products during loading and/or unloading is
prevented. For this purpose, each connective point for loading and unloading arms or hoses
has to carry a clearly visible and legible sign or name from which one can derive what product
the connective point is used for. For pipes meant for various substances one may deviate from
it, provided that one uses a procedure that prevents calamities on account of changing the
product.
97. Product pipes of loading and unloading installations that are not in use have to be closed with
a blind flange or at least a similar facility, so that leakage, also in case of a malfunction or an
operating error, is prevented. This does not apply to product pipes that do not contain a
product, are clean, and disconnected from the installation.
98. On the transfer location, in the direct vicinity of the transfer location or pier, and in the control
room from which the loading and/or unloading process is controlled, an easily accessible
facility needs to be installed to be able to stop the loading as soon as possible (emergency stop
procedure).
99. If television systems are used for supervision during loading and unloading, there has to be an
emergency stop procedure that can also be operated from the location where the monitor has
been installed.
100. Cameras on piers have to be installed in such a manner that during transfer activities they
can permanently monitor the quay as well as the ship.
101. By internal, written procedures drawn up in advance, one has to see to a proper
functioning of the loading and unloading hoses or arms present in the establishment. These
procedures have to pay attention to at least the following elements:
- such support, protection, operation, and storage, that damage is prevented;
- the falling or rising of the ship on account of the movement of the tides and the transfer;
- inspection of the good condition before the loading and unloading hoses or arms are used;
- not using damaged hoses;
- examination of reliability by pressure testing at least once every year at at least 1.35 times
the operating pressure. Hoses of third parties can be used in the establishment, provided that
they are inspected once every year in conformity with the prevailing Netherlands standard
NEN EN 12798 [Ref. 68];
33
- stamping in the date and quality mark of this pressure testing in a connecting flange or
connecting coupling; instead of stamping in date and quality mark, a registration system of
the pressure testing of the hoses can also be created, while a number has been stamped in
the flange or coupling of each hose that corresponds with this registration system;
- registration of the data of this testing and the retention of these data for at least two years.
102. Damaged hoses cannot be stored in the loading or unloading area.
103. If loading and unloading pipes and hoses are emptied after the transfer, facilities have to be
installed to let them empty before they are disconnected. The released substances have to be
collected in a system meant for this purpose. For residue of loading that has been left behind
unintentionally, a collection facility has to be available at the disconnection point.
104. Transfer can only take place in accordance with internal, written procedures drawn up in
advance, which pay attention to at least the following matters:
- that the staff that takes care of the loading sees to it that the correct identifying marks have
been placed on the means of transportation to be loaded, before loading is begun;
- that in the event of transfer of liquids, the operating staff makes sure that, before the transfer
by pumps begins, the parts to be used have been installed in such a manner that the liquid to
be pumped can only end up in the place meant for this purpose;
- that the operator, as well as the staff that takes care of the loading, has made sure in advance
that the receiving containment (tank, ship) has adequate space/capacity to safely receive the
volume to be transferred (product package).
105. During the loading and unloading of tank trucks and train tank wagons at least one
supervisor of the establishment has to be present in the loading and/or unloading area or in the
control room, who has a view of the loading and/or unloading activity and who causes the
transfer to stop immediately in case of malfunctions, leaks and/or irregularities.
7.3.2 Tank trucks and train tank wagons (loading and unloading stations)
106. The loading and/or unloading of a tank truck or train tank wagon on the top side can only
take place if there is a loading and/or unloading platform for this purpose or if a facility is
found on the tank truck or train tank wagon that makes it possible to easily reach the
filling/unloading opening of the tank truck or train tank wagon under any circumstances.
107. Shut-off valves, covers, and any other product shut-off devices of the tank truck or train
tank wagon have to be closed properly. Only the shut-off valve, the cover and any other
product shut-off device that is necessary to load or unload can be opened.
108. During the connection and disconnection of the loading and/or unloading pipe to the tank
truck, the engine of the tank truck has to be switched off.
109. During the connection and disconnection and during the transfer, the tank truck or train tank
wagon has to be parked in such a manner that driving away during the transfer activities is
prevented.
110. Before loading is begun, the correct distinctive marks have to be put on the tank truck to be
loaded or on the train tank wagon to be loaded.
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7.3.3 Ships (piers)
111. When transfer of a product that constitutes a fire hazard is transferred to a tank in which an
explosive gas mixture can be present and electrostatic loading is possible, the liquid velocity
in the filling pipe has to be limited to 1 m/s during an initial period as referred to in the
report “Risks of static electricity in the processing industry” in ASTM-D-4865-96 [Ref. 17]
and the NFPA [Ref. 78].
112. Piers and quays have to be created with a gradient, and have a raised edge on the side of the
water. There have to be facilities to prevent harmful direct discharges into the surface water.
113. The piers have to be built in such a manner that where tankers are loaded or unloaded, spilt
or leaked products, if any, or rain or rinse water polluted with products cannot flow to a
separator other than through a closed pipe, or can be pumped away or collected for drainage.
114. When quays and piers are cleaned, no spilling losses can end up in the surface water.
115. One cannot begin loading or unloading tankers before an internal, written procedure drawn
up in advance has been followed, containing that the “Safety Checklist for ocean-going
tankers” [Ref. 88], or for inland navigation ships the “Checklist ADNR” [Ref. 26], has to be
filled out completely. The regulations set in same or arising from same have to be included
in this procedure. The competent authority can set further requirements for this procedure.
The above provision does not relate to the necessity of placing insulation between quay and
ship, in as far as it concerns situations in which hose connections are used, provided that
adequate measures have been taken to the satisfaction of the Health and Safety Inspectorate
to prevent the creation of flammable and/or explosive gas/air mixtures.
116. In an internal, written procedure drawn up in advance it has to be included that, to prevent
overflow, spills, and leaks when loading and unloading inland navigation ships, as a
supplement to the valid provisions laid down in the “ADNR checklists”, agreements between
the ship’s crew and the staff on the quay are laid down in writing, notably in particular with
regard to:
a. the maximum pump velocity;
b. the maximum counter-pressure when pumping on the location of the quay/ship
connection;
c. the stop procedure in case of malfunctions;
d. the number and sequence of the switches to other ship tanks and/or land tanks to be
expected.
Furthermore, this procedure has to contain that these agreements are in the hands of the
responsible company officer during the stay of the ship at the pier of the establishment, and
that this procedure has to be retained at the establishment for at least one month. The transfer
has to take place in conformity with this procedure and the agreements.
117. There have to be means available to measure the counter-pressures and to determine the
loading and unloading velocities.
118. The loading and unloading of ships can only take place in accordance with internal, written
procedures drawn up in advance, containing at least the following elements:
- that connecting and disconnecting of loading and unloading arms or hoses takes place
under direct supervision of an officer of the quay installation;
35
- that a two-way communication system is maintained during loading and unloading of ships
when television systems are used;
- that the supervision is taken over by the responsible officer of the quay installation if,
when television systems are used, an unclear screen image has been created by whatever
cause;
- that during the transfer by pumping the supervision can only take place by a television
system, after the officer of the quay installation has determined that the loading and
unloading takes place without malfunctions and without risk of release of liquids or gases;
- that the officer of the quay installation takes over the direct supervision during loading or
unloading and takes measures when this is necessary for the safety and/or prevention of
emissions;
- that during loading or unloading, the officer of the establishment and a guard on the ship
constantly see to it that there are no leaks, spills, etc.
The supervision over the quay installation and the ship, as well as the communication
between the ship’s crew and the quay staff, has to be regulated identically for inland
navigation and marine navigation, as referred to in points a5 through a8 of the “Safety
Checklist for ocean-going tankers” [Ref. 26]. The communication system prescribed in point
a6 does not have to be applied if the communication is possible without tools, based on the
distance and the circumstances. If the officer of the establishment has determined that the
supervision on board a seagoing ship or the inland navigation ship is not conducted or not
adequately, he promptly has to take measures to restore the communication. He has to stop
the loading or unloading (cause it to be stopped) if the communication cannot be restored or
if there is an irregularity (leaks, spills, etc.).
119. On each pier where inland navigation ships are loaded, facilities have to be present with
which the overfill protection on these ships – as prescribed in Annex B of the ADNR – can
be connected to the overfill alert of the quay installation.
120. In the establishment only inland navigation ships that comply with Annex B of the ADNR
can be loaded.
121. When activating the outlet of the ship’s tank, as referred to in Annex B of the ADNR, optical
and acoustic alerts have to be switched on on the ship, on the pier, and in the control room.
The installations have to be designed in such a manner that on the side of the quay measures
can be taken with them against the overflow of liquid from the ship’s tank.
122. The overfill alert of the quay installation has to meet the prevailing requirements in
accordance with the German “Technische Regeln für brennbare Flüssigkeiten” [Ref. 87], or
directives to be put on a par with it, and this at the discretion of the competent authority.
123. The use of an overfill protection when loading and unloading ships can only take place in
accordance with internal, written procedures drawn up in advance, containing at least the
following matters:
- that the bridging or switching off of the overfill protection or parts hereof is not permitted,
unless it is necessary for safety;
- that bridging or switching off the overfill protection or parts hereof is indicated and
registered unequivocally in the control room of the quay installation;
36
- that during bridging or switching off of the overfill protection or parts hereof the loading
takes place under personal permanent supervision of the responsible officer of the quay
installation;
- that the overfill protections are inspected as to proper functioning before the beginning of
each loading. This inspection includes:
a. the functioning of the electric locking for the coming into operation of the overfill
protection of the quay installation;
b. the presence of the electric binary signal of the outlet of the overfill protection on the
ship’s tank for the automatic coming into operation of the overfill protection of the
quay installation.
7.4 Product pipes and pipe tracks
124. Product pipes are preferably installed aboveground.
125. Pipelines in which poisonous, stench-creating substances, and/or substances constituting a
fire hazard occur, as well as the appurtenances, have to be submitted to a pressure resistance
test before being put into operation, as referred to in the Pressure Equipment Commodities
Act Decree [Ref. 95].
126. There has to be a system from which it can be derived quickly what substance is in the
pipeline and what the direction of the flow is.
127. All sample points have to be provided with a clearly visible and legible sign or name from
which it can be derived for what product the connective point is used. For pipes meant for
different substances, this may be deviated from, provided that one uses a procedure with
which calamities on account of a change of product can be prevented.
128. Flanged joints, flexible joints, and bellows have to occur as little as possible.
129. Pipe trenches for pipelines between individual installations through which poisonous,
stench-creating, and/or flammable substances are transported, have to be subdivided by
means of liquid barriers/fire barriers. The mutual distance between these liquid barriers/fire
barriers has to remain limited to approximately 150 m.
130. Pipelines meant for products of classes 1 and 2 with a conductivity between 0.1 and 50 pico
Siemens per meter that end as an unloading point or end in vessels in which explosive
vapor-air mixtures can be present, have to be designed and manufactured in such a manner
that the electrostatic load present in these products is removed.
131. Pipelines have to be resistant to the load of traffic in case of a duct under a road.
132. Pipes and pipe supports that are located at a road have to be protected by a crash-barrier or
similar construction if a collision can cause a dangerous situation to the surroundings.
133. Underground steel pipelines with appurtenances through which soil-polluting substances are
transported have to be protected against corrosion in accordance with the prevailing
Netherlands standards and practical directives:
- NEN 6901 [Ref. 58];
- NEN 6902 [Ref. 59] and NPR 6903 [Ref. 79];
37
- NEN 6910 [Ref. 62] and NEN 6907 [Ref. 61] and NPR 6911 [Ref. 80];
- NEN 6905 [Ref. 60];
- or other similar standards or directives.
134. If soil examination, conducted by an organization designated or accepted by the competent
authority, establishes that:
- the specific electric soil resistance is smaller than 50 ohm.meter (in water extraction areas
100 ohm.meter) or
- the acidity (pH) is lower than 6 or
- the impact of stray currents is greater than what corresponds with the permitted
interference criteria or
- joints occur between dissimilar metals, which can cause galvanic corrosion or
- the environment is anaerobic,
the underground pipelines with appurtenances through which soil-polluting substances are
transported, unless there are objections for other technical reasons, have to be protected
against corrosion on the outside by a cathodic protection in accordance with NEN 6912
[Ref. 63]. Additionally, instead of the limit value of the metal-electrolyte-potential referred
to here, the polarization potential always has to be used. The cathodic protection has to be
inspected and approved by an organization designated or accepted by the competent
authority as to design, manufacture, and proper functioning.
135. New underground pipelines with or without cathodic protection have to be installed at such a
distance from other conductive underground objects that no mutual influencing takes place
that can lead to damage. For this purpose, the following minimum distances apply:
a. between pipes mutually 0.50 m;
b. for foundations, groundings of buildings, and constructions of electrical appliances: 0.70
m;
c. for underground high-voltage pipes: 5 m (nominal tension between the phases > 1,000 V
or between one phase and zero > 600 V).
136. Aboveground insulated joints of cathodically protected underground pipelines or equipment
have to be bridged in places where there may be a risk of explosion by spark-gaps in air-
tight casings in accordance with NEN 3125 [Ref. 53].
7.5 Product shut-off valves
137. All fast shut-off valves in product pipes have to be made fail-safe.
138. It has to be clearly visible on site on shut-off valves in product pipes that have to get into a
fail-safe mode whether they are opened or closed.
139. Shut-off valves in product pipes that are only used in exceptional cases have to be made in
such a manner, if a risk and/or any burden to the environment can arise due to incorrect use,
that direct control during normal operation is not possible.
140. To prevent undesired outflow, shut-off valves in product pipes that discharge into the
outside air and that are used in exceptional cases need to be equipped with blind flanges or
sealing caps.
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141. Shut-off valves and control valves in product pipes, necessary in emergency situations, have
to be operable on location as well as from at least one other location.
142. Fast shut-off valves in product pipes of which it has been established that they are essential
in emergency situations have to be operable electrically or pneumatically and also
manually.
7.6 Utilities
In an establishment steam, inert gas, and compressed air are used for various purposes. In this
directive, the regulations for steam and compressed air are not described. For this purpose,
reference is made to the directives concerned.
Nitrogen can be supplied through a pipeline. This pipeline has to meet what is stated in Chapter
7.4. In addition, it is possible that a reservoir for the storage of liquid nitrogen including the
vaporizer belonging thereto is placed on the installation.
143. The reservoir with vaporizer meant for the storage of liquid nitrogen has to be installed
outside in a well-ventilated place. The reservoir with appurtenances has to be protected
against collision.
144. The installation location cannot be lower than the ground level and preferably has to be
surrounded by a two-meter high fence. If there is a chance of subsidence, an adequately
solid foundation has to be created that can support the weight of the reservoir including its
content.
145. The reservoir with appurtenances has to meet the requirements set by the recognized
supplier.
146. The distance from the reservoir with appurtenances to the other parts of the installation has
to comply with what is stated in Chapter 5.
147. The reservoir with the filling point belonging thereto has to be placed in such a manner that
the installation always remains easily accessible for the tank truck and that the driver of the
tank truck has a good view of the installation and the tank truck.
148. When filling the reservoir, the connective point of the unloading hose to the tank truck with
which the liquid nitrogen is supplied, has to be in a section within the establishment meant
for this purpose. The level of the filling of the reservoir has to be visible from that location.
149. The filling point of an installation has to be affixed so tightly that it is prevented, if the
unloading hose is not disconnected, that the reservoir is pulled away by the tank truck
driving off, or it needs to have a drive-off protection. The filling point also needs to have a
collision protection.
150. The connecting joint of the filling pipe of the reservoir has to be properly supported and
meant specifically for liquid nitrogen.
7.7 Offices, workshops, and laboratories
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151. The distances of the offices, workshops, and laboratories to the other parts of the installation
have to comply with what is stated in paragraph 4.3.
7.8 Control rooms
This directive does not give regulations for control rooms. The current prevailing standards for
control rooms are:
- CIA (Chemical Industries Association); Guidance for the location and design of occupied
buildings on chemical manufacturing sites [Ref. 25];
- API recommended practice 752 [Ref. 6].
For further explanation, please contact the Health and Safety Inspectorate.
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8 Firefighting facilities
8.1 In general
152. If tanks for substances of class 3 have been installed in a tank farm containment area with one
or more tanks for substances of classes 1 or 2, these tanks have to be equipped with a
refrigerating facility and fire extinguisher as required for substances of classes 1 or 2.
153. External floating roof tanks sharing one tank farm containment area with one or more tanks
with fixed roofs have to be equipped with a refrigerating facility and fire extinguisher as if
they were tanks with fixed roofs.
8.2 Fire extinguishers
154. Tanks in a tank farm containment area for the storage of substances of class 3 have to be
equipped with a stationary fire extinguisher that complies with the NFPA 11 [Ref. 71]. In
deviation from it, mobile means can be used, provided that:
- the tank is easily accessible for the company fire department and the fire extinguishers used
by the Fire Department, and;
- the accessibility and method of firefighting by means of an operational plan has been laid
down in the fire safety plan.
155. Tanks with a fixed roof in a tank farm containment area for the storage of substances of
classes 1 and 2 have to be equipped with a stationary fire extinguisher complying with the
NFPA 11 [Ref. 71]. Storage tanks with a fixed roof and an internal floating roof, an inert gas
cover and detection of the functioning of the inert gas cover do not require a stationary
extinguishing system.
Explanation:
An inert gas cover (for instance nitrogen) needs to be designed in conformity with the NFPA 69 in
combination with independent detection of the concentration of inert gas or oxygen.
156. The facilities for the supply of foam to the tank cannot be affixed to the roof construction.
These facilities have to be affixed in such a manner that no stored liquid can get in the
supply facility.
157. The stationary fire extinguisher can be refrained from in case of storage tanks with a diameter
of less than 19 m, if:
- a quantitative description has been made of the maximum fire scenarios (tank fire and tank
farm containment area fire) and the thermal load (maximum 10kW/m2) belonging thereto;
- there is an operational plan to fight the fire in the storage tank with mobile means,
including an overview of means necessary, the graphic chart of the positioning of the
41
means, and the division of the tasks between the company fire department and the Fire
Department;
- the operational plan has been approved in writing by the Fire Department.
158. External floating roof tanks have to be equipped with a stationary fire extinguisher for a fire
in the rim seal that meets the NFPA 11 [Ref. 71].
The Fire Department has to be able to make a primary attempt to extinguish a rim seal fire
without entering the tanks. For a secondary attempt and spills on the roof, the tank has to be
equipped with a dry riser pipe, a wind girder to be accessed safely, and sufficient mobile
equipment has to be available.
8.3 Firewater system
159. The firewater system has to be designed in accordance with directives of the NFPA, notably
NFPA 11 [Ref. 71], NFPA 14 [72], NFPA 20 [Ref. 73], NFPA 22 [Ref. 74], and NFPA 24
[Ref. 75].
160. A drawing in scale of the firewater net has to be available, indicating:
- the location of the firewater pumps (including capacity and pressure);
- the locations of the pipes;
- the diameter of the pipes;
- the locations of the globe valves;
- the fire hydrants and the stationary monitors (including fire hydrant numbers).
8.3.1 Capacity of the firewater system
161. The firewater system has to be designed for the supply of the amount of water that is at least
needed for each different fire scenario on the location in question within the establishment.
This amount of water always has to be adjusted to both extinguishing a burning surface with
water and foam and the refrigerating of installations at risk. At any rate, the fire-extinguishing
system has to be able to provide at least 6,000 l/min (360 m3/h) on any location within the
establishment with three fire hydrants located next to each other.
162. The amount of water to be used to extinguish needs to be sufficient for the maximum burning
surface on location, for instance on account of the failure of storage tanks.
Explanation:
The maximum burning surface is:
- in case of tank farm containment areas with tanks with a fixed roof or tanks to be put on a par with
same, the maximum burning surface equaling the surface of the tank farm containment area minus
the surface of the tanks, except for the largest tank;
- in case of tank farm containment areas with dividing dikes, the maximum burning surface
equaling the largest liquid surfaces in the event that a fully filled tank yields;
- in case of tank farm containment areas containing only tanks with a floating roof the surface of the
largest tank has to be taken into account.
The amount of water needed depends on the manner of extinguishing. The calculation hereof
has to comply with the NFPA 11 [Ref. 71] in the practical situation, viz. corrected as to the
capacities of the refrigerating installations and fire extinguishers.
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163. It has to be possible to supply the amount of firewater and cooling water needed under any
circumstances for an unlimited period of time. In consultation with the Fire Department, this
may be deviated from.
Explanation:
In this respect, the availability of secondary firewater facilities and the extent to which one
extinguishes or refrigerates by means of (semi-)stationary means is of importance. The Fire
Department has to confirm permitted deviations in writing. The action to be taken has to be included
in the emergency plan.
164. In the event of diminished availability of the pump system, for instance because of
maintenance or repair, it always has to be possible to supply 75% of the necessary capacity
by means of one’s own firewater system. In order to guarantee that the capacity requirement
of 100% is met, the establishment also needs to have alternative pump capacity, for instance
spare pumps, a fireboat connection or coupler between one’s own firewater system and that
of an adjacent company.
8.3.2 Design of the firewater system
165. The firewater net has to be manufactured as a ring main system and be equipped with globe
valves. The globe valves have to be installed in such a manner that when a section is put out
of operation sufficient firewater remains available for every section of the establishment.
Explanation:
When putting a section out of operation, it has to be determined in what other manner the firewater
facility for this section can be guaranteed. Firewater has to be available at least up to halfway down
the street qualifying for it and at least from two sides of an installation. The temporary change has to
be reported to the company fire department, Fire Department, and if necessary, competent authority.
166. The firewater system and the system of the Fire Department have to be adjusted to each
other. The draft drawing and the description of the firewater net require the written approval
of the Fire Department.
167. Sufficient aboveground fire hydrants and aboveground fire hydrant/monitor combinations
(“aboveground fire hydrants” hereinafter) need to be installed on the firewater system. The
required number depends on the different fire scenarios and the capacity of the individual
aboveground fire hydrants. Except on open, not built-up land, the aboveground fire hydrants
have to be installed at a mutual distance of 50 m to 80 m, unless deviating risk-increasing
activities in the direct vicinity require an increased need for firewater. The aboveground fire
hydrants have to comply with the NEN-EN 14384 [2005]. In places where deviating risk-
increasing activities take place, this mutual distance has to be evaluated for each individual
case, for instance for piers, pump-pads, and loading stations.
168. The diameter of an aboveground fire hydrant has to be at least 80 cm. An aboveground fire
hydrant needs to have at least two connections. Each connection has to be equipped with
shut-off valves belonging thereto, with a diameter of the passage of at least 67 mm, with a
Storz coupling with a cam distance of 81 mm. If the aboveground fire hydrant has shut-off
valves with a passage of 110 mm, the cam distance of the Storz coupling has to be 115 mm.
169. The aboveground fire hydrants have to be equipped with an efficient drainage, so that they
cannot freeze. In order to fight corrosion, aboveground fire hydrants have to be equipped
43
with an effective coating and, if necessary, protected with a cover that can be removed
quickly.
170. Aboveground fire hydrants need to have a unique number that is indicated clearly on or near
the aboveground fire hydrant. It has to be possible to open aboveground fire hydrants with a
tap wrench customary with the Fire Department or they have to be equipped with a tap
wrench belonging thereto that is permanently connected (for instance with a chain) to the
aboveground fire hydrant.
8.3.3 Firewater pump system
171. The fixed firewater pump system installed has to meet the necessary firewater and/or cooling
water capacity for the maximum fire scenario to be expected, with a minimum of 360 m3/h.
The pump system has to be able to supply the necessary capacity at all times. It has to be
possible to start the firewater pumps from a permanently staffed, safe location.
Explanation:
Toxic scenarios can also influence the necessary capacity.
172. The firewater pump system has to be adjusted to the maximum necessary pressure to be
expected on every individual location within the establishment. The necessary dynamic
(working) pressure has to be determined per fire extinguisher and/or refrigerating
installation. For aboveground fire hydrants, a minimum dynamic pressure of 1 bar (100 kPa)
is necessary, this does not apply to monitor combinations.
173. The location and capacity of alternative pump facilities and operating instructions have to be
included in the (emergency) instructions.
Explanation:
See for emergency instructions and emergency plan paragraph 9.5.1.
174. If a tank installation is located at a waterway and the local or regional emergency services
have fireboats, the following regulations apply:
- Fireboat connections have to be connected to the firewater pipe of the company by a
coupler with a diameter of 8 inch (200 mm). This coupler has to be equipped with a shut-
off valve.
- The standard connections for fireboats have to be manufactured with four connections
with a loading diameter of 75 mm [… word missing; translator] by NEN EN 10025 [Ref.
96] that have Storz couplings with a cam distance of 81 mm, and two connections with a
passage diameter of 100 mm, that have Storz couplings with a cam distance of 115 mm.
- Each connection needs to be manufactured with a 75 mm (3 inch) or 100 mm (4 inch)
shut-off valve with non-return valve.
- Each fireboat connection has to be accessible for a fire boat at all times. The mooring place
for a fireboat near each fireboat connection has to be indicated by one or more signs
“Aanlegplaats Blusboot” (mooring place fireboat) or a square sign with a red rim carrying
the letter B, which is clearly visible and legible on the quay side and on the waterside.
175. If the company’s firewater system or its own pump capacity has not been adjusted to the
maximum fire scenario, a logistics plan has to be submitted to the Fire Department for
approval. The logistics plan contains the calculations, the necessary means, and the
44
established division of tasks and responsibilities between the company’s fire department and
the Fire Department. In connection with the logistics plan, additional facilities, such as
ramps for mobile monitors and areas for hose tracks have to be created. The logistics plan is
part of the fire safety plan and has to be kept up-to-date.
176. The manner of firewater drainage has to be described in (emergency) instructions and
included in the emergency plan.
Explanation:
See for emergency instructions and emergency plan paragraph 9.5.1.
8.4 Refrigerating systems
177. Except in situations as described in the following three regulations, storage tanks have to be
equipped with their own stationary refrigerating facility against heating due to an external
fire. The refrigerating facility has to give an equal coverage pattern of cooling water over the
entire tank surface.
The stationary refrigerating facility has to be designed in accordance with a recognized Code
of Practice as that of the NFPA and the IP part 19 [Ref. 44].
Explanation:
In a system the cooling water of which is divided over the walls from above, a flow of at
least 17 l/min of cooling water per running meter tank circumference is required. For the
other systems, the minimum cooling water flow is 2 l/min per m2 of tank surface. More
information on refrigerating facilities can be found in the code IP part 19, Annex 2 [Ref. 44].
This code also provides other application amounts for other installations than tanks.
178. Tank farm containment areas with only storage of liquids of class 3 do not need to have
stationary refrigerating if:
- in and around the tank farm containment area sufficient means are available to extinguish a
small fire in the vicinity; Explanation:
The means chosen have to be demonstrably equipped for the scenarios intended.
- there is a description at the establishment in which manner the tank is protected against
escalation of credible incidents in adjacent objects.
179. In tank farm containment areas for storage of substances of classes 1 and 2 in tanks with a
fixed roof, stationary refrigerating can be refrained from if all the following conditions are
met:
- the distance between the tanks has to be such that in the event of a fire in an adjacent tank
a lower thermal load than 10 kW/m2 is reached;
- the compound of each tank individually needs to have a collecting capacity of 100% of the
tank capacity;
- the fire hazard in the vicinity has to be small.
180. In tank farm containment areas with external floating roofs, stationary refrigerating can be
refrained from, provided that the distance between the tanks is such that in the event of a fire
in an adjacent tank, a thermal load of 10 kW/m2 cannot be exceeded and the fire hazard in
the vicinity is small.
45
Explanation:
For this purpose one has to proceed on the valid reference scenario for floating roof tanks. For tanks
with detection in the rim seal and a stationary extinguishing system that complies with the NFPC 11
[Ref. 71] this is a rim fire. Without these facilities, it is a tank fire.
181. The following applies to the other parts of the tank installations:
- installations/objects/supporting structures that can be grit blasted with a thermal load
higher than 10 kW/m2 and with which a failure or expansion of the fire created can be
caused on account of the thermal radiation have to be protected against too high a thermal
load;
- if refrigerating with mobile means is desired, the effectiveness of it has to be proven in the
fire safety plan by calculations and a graphic chart.
8.5 Foam extinguishers
182. The amount of foaming substance that has to be present on the site depends on the need for
foam. The need for foam depends on:
- the surface of the largest tank farm containment area for areas with fixed roof tanks;
- the surface of the largest tank in case of external floating roof tanks;
- the surface of a compartment of a pipe track or pump-pad.
The need for foam has to be determined in accordance with NFC 11 [Ref. 71].
183. The type of foam and the expansion capacity of the foam has to be adjusted to the nature and
amount of the substances and risks present. The stability and applicability of the foam should
have been proven by testing by an organization recognized by the competent authority.
184. The foaming substance has to be of such a nature and be retained and stored in such a manner
that it continues to meet the specifications of the manufacturer. The proper functioning of the
foaming substance has to be proven upon demand of the competent authority. In order to
guarantee the proper functioning of the foam, once every year:
- the foaming substance has to be inspected visually with regard to occurrence of film,
pollution and sedimentation;
- refraction measuring of the foam mixing system has to be performed.
185. There has to be consensus with the Fire Department on the type of foaming substance.
186. Foaming substance has to be stored in such a manner that, in case of a calamity, quick and
adequate transportation is possible with the means present on site.
8.6 Fire detection
187. Locations in a danger zone need to have a fire detection system. Continuous supervision and
quick detection of an incident are also required.
Explanation:
Within this framework, the provisions under 192 and 193 are also of importance.
188. The selection of the detection system and the refrigerating facility and fire extinguishers also
depends on the storage tank and the local situation. So it is possible to (temporarily) deviate
from the status of safety technology in particular cases. Deviating from the described safety
46
level, supported by reasons, has to be agreed on in consultation between the competent
authority and the operator, while the following conditions should be met:
- a safety policy and scenario analysis have been carried out (paragraph 8.3);
- there is a description of the effects and the manner in which they have to be fought;
- the tasks of the control have been included in operational plans and procedures of the
organizations involved;
- deviating from the safety level described in this directive has to be approved in writing by
the (municipal) Fire Department.
Explanation:
On this point, legal responsibilities, labor conditions, financial and social aspects are relevant.
189. External floating roof tanks have to be equipped with a linear heat detection system or similar
facility. In case of storage tanks with a diameter smaller than 19 m this may be deviated
from, provided that the competent authority is of the opinion that adequate supervision is
present.
Explanation:
Adequate supervision is understood to be continuous presence of manpower, the extent to which
supervision is conducted on the location of the storage tank (control rounds). Rim fires are hard to
detect visually.
8.7 Report and alert facilities
190. A fire report system with which one can easily and quickly report a fire or serious leak from
various locations on the site to a continuously manned post has to be present within the
establishment. This report system can only be used to report emergencies.
191. The establishment needs to have an alert system with which all those involved can be warned
in case of serious leakage, fire, or other irregularities. It has to be possible to switch on this
alert system from various places on the site. The alert signal has to be audible for everyone
on every location within the establishment. This alert system can only be used for alert.
Explanation:
“All those involved” can also include adjacent companies and their staff, if there can be question of
an increased risk for them.
192. The signal of an automatic detection system has to be received on a continuously manned
report post or passed on directly to the emergency center of the regional emergency services.
The detection system has to comply with what is specified in NEN 2535 [Ref. 51], including
amendment sheet NEN 2535/A1.
193. The signal of the detection system can only be passed on with delay with written permission
of the Fire Department. This permission can be evaluated and revised, if necessary, by the
Fire Department periodically.
8.8 Other facilities
194. Near the pump-pads of product pumps and transfer piers for substances of classes 1 and 2,
sufficient permanent water monitors have to be set up to prevent a pump-pad fire and a pier
fire in case of a fire in the vicinity. Monitors meant for foam suppletion need to have
47
sufficient capacity to provide the entire pump-pad with a layer of foam in conformity with
NFC 11 [Ref. 71].
195. Within the establishment, provisions have to be made to determine the wind direction.
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9. Safety control measures
The regulations in this Chapter have already been largely incorporated in the safety report and
the prevention policy for establishments that fall under the direct scope of the Major Accidents
(Risks) Decree (“BRZO”).
9.1 Safety policy
196. The operator should have identified and evaluated the dangers and (the internal and external)
risks attached to storage and transportation of the products. Subsequently, it should be
recorded in writing how these dangers and risks are controlled (policy/objectives). The
control measures should constitute an adequately safe and reliable situation in connection
with design, construction, operation, maintenance, and the like.
197. Within the establishment an up-to-date fire safety plan has to be present. The fire safety plan
has to contain at least:
- the company policy on preventing, controlling, limiting, and fighting incidents;
- a quantitative description of one or more typical incident scenarios for each installation
unit;
- a general strategy for the repression of the incident scenarios;
- an overview of the necessary facilities, tools, and control measures to limit, control and
fight incidents;
- the persons and/or positions that are responsible for monitoring the integrity of these
facilities, tools and control measures.
198. The fire safety policy has to be spread actively by the operator.
199. The Fire Department may set further requirements for the content of the fire safety plan.
200. The fire safety policy and the fire safety plan have to be kept up-to-date.
Explanation:
The fire safety plan has parallels with the Safety Report (“VR”), as referred to in the Major Accidents
(Risks) Decree (“BRZO 99”) and the Company fire department report from the Fire Services Act
[Ref. 21]. However, the fire safety plan also has elements from “Fire Plans” as described in standards
such as the part 19 of the IP (Chapter 9) [Ref. 44].
9.2 Staff: skill, training, alertness
201. Within the organization, the following matters have to be described or guaranteed
procedurally:
- the tasks and responsibilities of the staff (the company’s own staff and that of third
parties) that is involved in controlling the risks during the normal business operations as
49
well as in emergency situations. The minimum staff available within the establishment has
to be adjusted to it;
- the manner in which the communication takes place when the shift handovers take place.
The transfer of information has to take place verbally and in writing. A system to record
the information has to be available;
Explanation: when a shift handover takes place, it is important that sufficient time is
dedicated to it and that it is recorded what information has to be transferred; one may
think of:
- current and planned product moving;
- bridged protections and bypasses;
- malfunctioning equipment or equipment that is not in operation;
- maintenance activities and work permits issued;
- recently activated (critical) alerts, trips, etc. and actions taken;
- incidents occurred;
- staff present/persons on site;
- etc.
- identifying the necessity to train the company’s own staff and that of third parties in
relation to the control of risks and the details and follow-up hereof.
202. Staff (the company’s or that of third parties) performing work near or at the installations have
to be familiar with the safety regulations, the regulations in the event of fire, and the
practical use of small extinguishers in as far as it applies to them.
Explanation:
In Chapter 8 of the Working Conditions Decree [Ref. 10], the use of personal means of protection is
described. Each operator has to determine and record at any rate based on an analysis when what
personal means of protection have to be worn and why.
203. The staff needs to have been instructed and trained with regard to the emergency plan.
204. Within the establishment, a person has to be appointed who is responsible for:
- the periodical inspection of the fire extinguishers;
- testing the proper functioning of the fire extinguishers;
- the organization of the trainings required;
- taking measures to keep the company fire department and the company emergency service
trained;
- updating the emergency plan.
9.3 Scenario description and accident analysis
The level of fire safety needed depends on the risks of the establishment, the vulnerability of its
surroundings, and the (operational) possibilities of the Fire Department. If necessary, the Fire
Department can set further requirements that go beyond this directive.
Explanation:
The determination of the desired fire safety level has to be based on an accurate analysis. Tools are
available for this purpose in the form of specific cause and effect diagrams of tank incidents, codes of
the NFPA and publications of the Fire Department Rotterdam (Center Industrial Safety, 2003).
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205. The operator has to draw up procedures for the systematic identification of possible undesired
incidents (accident analysis). For this purpose, several risk evaluation and control methods
are available.
Explanation:
It is mainly of importance that the operator makes an inventory of what possible undesired incidents
can occur, what the consequences of these incidents (can be) are and what measures and provisions
have been taken to prevent these incidents and to limit their consequences. The reliability of the
measures and provisions taken are also important factors in both the safety studies themselves and in
the actual business operations.
206. To conduct the accident analysis, one has to take into account the policy to control scenarios
drawn up by the operator. A burn-out scenario is not accepted, unless there is explicit
consensus with the Fire Department on this point.
Explanation:
API RP 2021 [Ref. 8] provides an accepted standard for the scenarios.
207. The operator has to dispose of a document describing the identification of possible
emergency situations adequately and systematically.
Explanation:
It has to be recorded at least:
- who is involved in this identification;
- the methodology with which scenarios are identified;
- what accident scenarios are identified;
- the relevant factors belonging thereto (effect and damage development);
- an analysis based on a risk and impact evaluation of the possible emergency situations;
- the relevant legislation;
- relevant possible emergency situations from outside the site;
- the scope of these studies depends on the size of the installations.
208. The measures taken to control scenarios should all have been recorded in a system that
guarantees the integrity of these measures.
209. The operator has to make an analysis of undesired incidents that have occurred and report
them to the competent authority.
9.4 Supervision over the execution
210. Within the organization, establishing and applying procedures and instructions to control the
safety of the business operations, including the maintenance, the preservation of the
installations, and the temporary interruptions, has to be described.
Presence staff
211. At all times during work at least one responsible person has to be present at the site or it has
to be possible to reach him, which person is sufficiently expert and familiar with the safety
means present and able to take the measures required in the event of a fire or accident. In
consultation with the competent authority this may be deviated from.
Explanation:
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For larger and more complex installations, the competent authority may set additional requirements,
for instance:
- On sites where work is performed, there constantly have to be at least two responsible persons
present, both day and night, who are sufficiently expert and familiar with the safety means
present. They also have to be able to take the necessary measures in the event of a fire or
accident.
- The company has to dispose of a well-trained firefighting and emergency service team.
- These teams have to consist of staff from the establishment itself, if necessary in cooperation with
third parties.
- Clear arrangements have to be made on managing and alerting the teams.
- The staff that is part of aforementioned teams has to be trained with regard to the use of fire
extinguishers and tools.
9.5 Being prepared for and respond to emergency situations
212. The operational plan has to contain a suitable response (Emergency Response Plans) for
every identified scenario.
213. The means needed to execute the operational plan have to be contained in the maintenance
and inspection system and tested regularly.
213A An analysis of all vulnerable and critical emergency provisions has to be made with regard
to possible alternatives in the event that they fail.
214. The persons involved have to be instructed adequately and trained regularly.
9.5.1 Procedures and instructions
215. The function and operation of fire safety facilities have to be recorded in an (emergency)
instruction (= emergency plan). It has to be available to the one carrying out the acts in
emergency situations.
216. The operator of a tank installation should have an emergency plan ready.
217. The emergency plan has to be approved by the competent authority and the Fire Department.
Explanation:
The emergency plan should contain:
- for the scenarios referred to in paragraph 8.3: a description of the effects, the means present, and
the measures to be taken. In practice, this can be the manual of a stationary system or an attack
plan for use of mobile means;
- a description of the measures to be taken to control the situation or the incident and to limit its
consequences;
- a description of the safety equipment and means available;
- the manner in which the results of inspection rounds regarding the presence and efficiency of fire
safety equipment are recorded in a registration;
- the measures to limit the risk for persons within the establishment, including the alert system and
the rules of conduct in the event that the alert sounds;
- a detailed emergency instruction for the high-risk units;
- receiving/guiding the Fire Department;
regulations to notify the authority responsible for putting the external emergency plan in
operation in the event of an accident;
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regulations for the information that has to be provided immediately and regulations for
providing more extensive information when it becomes available;
organization of the communication to others (press, adjacent companies, neighbors);
a procedure for periodical verification of the adequacy of the procedures and (fire
extinguishing) means and, if necessary, update of the emergency plan;
- an organizational chart of the emergency organization;
- tasks, powers, and responsibilities of the emergency organization;
- a training profile of the emergency organization.
When the emergency plan is set up, one has to take into account that it may be necessary in
the event of a leak or fire to evacuate certain parts of the site or to warn neighbors.
A guideline for the setup of an emergency plan was laid down in the IBBB of the Ministry of
the Interior and Kingdom Relations. The Center Industrial Safety of the Safety Region
Rotterdam Rijnmond inserted a guide for setting up emergency plans for tank installations in
its Technical Frame of Reference for storage tanks. (O)
9.5.2 Incident and accident report
218. In two places within the establishment (inter alia with the doorman, provided there is one)
the following up-to-date information has to be available:
- a plan of the establishment with the buildings, installations, and relevant pipes present;
- a drawing showing the location of the firewater pipes and connections, fire hydrants, globe
valves and the information on capacity and pressure;
- a list of the size and maximum capacity of the installations and tank farm containment
areas;
- an overview of the products present with their nature and the pressures and temperatures
present;
- a plan showing where the fire trucks can drive and whether all installations/buildings can
be reached by the Fire Department from two sides;
- an overview of facilities in/on the installations;
- an up-to-date internal emergency plan;
- the function of and instruction for the functioning of the stationary fire extinguishers
present;
- a drawing showing the location of the drainage and sewage facilities, the location of inlets
and shut-off valves, the location and capacity of storage facilities, the location and capacity
of pumps.
The places for retention of aforementioned data are located in such a manner that this
information is available at all times and the chance that the information is affected is
minimized.
219. Upon arrival of the Fire Department in the event of an emergency situation, it has to be
possible to give the commander the information referred to in the above regulation
immediately.
9.5.3 Drill
220. Regular drills (on paper and in practice) have to be held based on the various accident
scenarios laid down. In addition to drills for the firefighting teams (company fire
department), drills and trainings for office staff, contractors, and external emergency services
also have to take place.
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221. A (multi-year) drill program has to be available for the drills. This is shown to the competent
authority upon request. There have to be a script and an evaluation for every drill, which
have to be retained for at least 5 years.
Explanation:
The Netherlands Institute for Fire Service and Disaster Management (“NIBRA”) developed some
tools for organizing, carrying out, and evaluating drills. In addition, the Ministry of the Interior and
Kingdom Relations has some guidelines for the experience of emergency services staff and
(company) fire department staff.
9.6 Cooperation
222. It is permitted to provide for foaming substance or fire extinguishers together with one or
more other companies in the vicinity. If a company is a member of an industrial firefighting
pool, part of the stock of foaming substance can be stored outside one’s own site. In a
logistics plan, the operator has to indicate how far the stock within the establishment has
been reduced, while it remains secured that foam extinguishing can be begun immediately.
The logistics plan has to contain the tasks and responsibilities laid down with regard to the
foam system in the event of the maximum fire scenario.
Aforementioned working method is only permitted after approval by the Fire Department.
Approval cannot be granted if the preventive and preparative requirements in this directive
are not complied with. Conditions in this respect are that:
- the means of the industrial firefighting pool are brought to the company immediately,
and one can promptly begin controlling and fighting the incident. For major incidents,
such as tank fire of a tank with a diameter of 80 m, the firefighting has to be begun
within four hours;
- the obligation to prove the functioning (integrity) of the logistics plan is the
responsibility of the operator;
- the operator has described the working method in a plan that has to be approved by the
competent authority.
223. The amount of foaming substance present on the site cannot be less than the sum of:
- the amount necessary in automatic extinguishing systems;
- the amount of foaming substance necessary for quick scenarios (covering toxic pool,
etc.);
- the amount necessary to conduct tests and to hold drills, or;
- the amount stated in a decision pursuant to Article 13 Fire Services Act or required
based on the environmental permit.
224. If the firewater necessary for the maximum scenario is not available on the site, additional
facilities should have been realized, such as slopes for submersible pumps, prepared rooms
for hose tracks, hook-arm vehicles etc.
Explanation:
These facilities are only acceptable in existing situations and/or in case of excessive costs of
stationary firewater facilities.
9.6.1 Supervision over performances
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224a. The operator periodically has to evaluate the effectiveness of the prevention policy and the
control measures (see paragraph 9.7). For this evaluation, concrete and measurable
(SMART) objectives should have been established per control element, as well as a
continuous supervision over the (safety) performances.
For the supervision over the performances, a procedure has to be established and applied for
the permanent evaluation of these objectives of the policy to prevent incidents and
accidents, and of the effectiveness of the safety control system, as well as the
implementation of regulations for investigation and correction in the event of non-
observance hereof.
Explanation:
The tasks, powers and responsibilities concerning the collection and interpretation (inter alia trend
analysis/investigation underlying causes) of data/information related to the safety performances,
serving as input for the assessment and evaluation, have to be recorded in the procedure.
Performance indicators can be set up as a derivative of safety objectives.
9.7 Assessment and evaluation
225. The operator has to lay down, apply, and assess with regard to effectiveness, procedures for:
- the systematic periodical evaluation of the policy to prevent accidents;
- the evaluation of the effectiveness and reliability of the safety control system;
- the analysis, supported by documents, of:
* the results of the policy pursued;
* the safety control system;
* the updating of the policy pursued and the safety system.
These procedures require the approval of the competent authority.
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10. Fire prevention and safety
This Chapter contains the main features of the facilities and requirements serving to determine the
necessary level of firefighting. The measures to be taken by the operator are elaborated in a fire
safety plan. A relation between these facilities and the control measures described in Chapter 11
is necessary.
Avoiding ignition sources
226. An open fire cannot be present in a danger zone and no smoking is permitted there. This
prohibition does not apply to installations or areas in a danger zone that are fitted up or
protected against the risks of fire and smoking, and where it is clearly indicated that fire and
smoking are permitted.
227. This provision may be deviated from if work has to be performed for which fire is necessary,
provided that the operator has given a written exemption for every such case, after he has
ascertained that this work can take place without extra risk. On site, a written certificate has
to be present that this work is permitted or has been registered at the control room.
228. The smoking and fire prohibition has to be announced clearly with signs and a symbol in
accordance with the standard NEN 3011 [Ref. 52]. These signs and symbols have to be
affixed near the access to the site of the establishment and on locations constituting a fire
hazard. They have to be properly legible and visible.
229. Fire extinguishers and tools, such as hoses, have to be stored in easily accessible closets. The
closets have to be placed in a noticeable place and provided with doors, clearly specifying
the content of the closets. The closets have to be painted in the color red in accordance with
the standard NEN 3011 [Ref. 52].
230. In the event of incidents, the connective and operating points of the firewater system,
refrigerating systems, extinguishing systems or other stationary and mobile equipment
important to fight the incident cannot be exposed (unprotected) to a radiation load of over
3kW/m2. These points need to have remote control equipment that is resistant to the
maximum radiation load occurring on site. Protection against maximum radiation load on the
operating points can also be realized by firewalls with sight-glasses.
231. If requested, the operator has to prove this by a plot card with radiation contours.
Explanation:
For mobile equipment it appears from the initial plans whether this requirement of exposure is met.
10.1 Tests upon delivery
10.1.1 Installation pipes
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232. Testing installation pipes, constructing parts of pipes together to a combination and putting
into operation have to take place in conformity with the provisions in Chapter III and
Chapter IV of the Pressure Equipment Commodities Act Decree [Ref. 95].
10.1.2 Tank heating
233. Testing heating elements such as spirals and plug-in heaters with a design pressure > 0.5
barg. has to comply with the Pressure Equipment Commodities Act Decree [Ref. 95].
234. If a new construction certificate for the storage tank is required by the license-granting
agency (“certificate of first press”), a conformity evaluation has to be conducted for the tank
heating as if it concerns a “category IV” device as referred to in the Pressure Equipment
Commodities Act Decree [Ref. 95].
235. The organization accepted by the competent authority gives the manufacturer an evaluation
report, showing that the design meets the standard set, while the supervision is extended as if
it were a module G device in category IV as referred to in the Pressure Equipment
Commodities Act Decree [Ref. 95].
10.2 Independent supervision
236. During the new construction or reconstruction (not being repair) of the storage tank,
supervision has to be conducted by an expert employed with the organization accepted by
the competent authority.
237. The supervision has to contain control activities during the construction of the foundation
and of the storage tank.
238. Control activities during the construction of the foundation have to consist of:
- soil examinations to provide a clear understanding of the composition of the compressible
layers and their load-bearing capacity (see Annex A). Based on already available
information, this may be deviated from in consultation with the soil-mechanical engineer
and the license-granting agency.
- the predicted setting and changes in setting have to give a picture of the expected behavior
of the tank floor and the tank wall.
- during the filling or the water test of the tank, the setting of the foundation and the effect
hereof on the tank construction has to be inspected, while the results have to be recorded in
an acceptance document.
239. The supervision during the construction of the storage tank has to consist of:
- the material applied with required notch toughness properties of the material concerned;
- the required welders’ and welding method qualifications;
- the welding examination conducted with the accompanying non-destructive welding
examination;
- a leak-tightness inspection of the floor plates;
- an anchor test of a necessary anchoring of the tank;
- the water test of the tank with a tightness inspection of the roof;
- inspection of the unhindered rise and fall of an internal floating roof;
The results of the inspections have to be recorded in a result document.
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10.3 Inspection program
240. The program of control activities during the construction or reconstruction of the storage tank
has to be laid down by the accepted organization in conformity with the proposed standard
when it evaluates the construction of a storage tank.
This organization has to give the builder of the tank an evaluation report with an inspection
program attached to it. The evaluation report has to show for what design conditions the
construction is deemed acceptable and what standard it is based on.
The accepted organization has to give this document a unique number, while the future tank
owner has the obligation to retain it.
10.4 New construction certificate
241. Upon completion of the construction and before the tank is put into use, the accepted
organization has to issue a certificate of a first test, confirming that the tank was built or
constructed in conformity with the standard set. The certificate also has to contain the
following data:
- the logo of the accepted organization;
- manufacturer information;
- the year of manufacture;
- the evaluation standard of the storage tank;
- the design conditions;
- the numbers and issue of the approved drawings;
- data concerning the test;
- a reference to the inspection program in conformity with the evaluation document issued.
10.5 Safety systems
242. Safety systems such as means of detection and firewater system have to be tested by an
independent inspection institute upon delivery and periodically after having been put into
operation. The test has to be conducted in accordance with a test protocol approved by the
competent authority and under the supervision of the Fire Department. The test protocol and
the report of the test have to be retained during the service life of the device.
Explanation:
The independence of an inspection institute has been laid down in the EN-45004 [Ref. 38].
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11. Business operations and management
11.1 Operational supervision and inspection
243. The proper functioning of the installations is managed systematically while using:
- regular visual inspection of the condition of the installations and the company site as to
irregularities, if any, that have occurred (such as damage or leaks not detected earlier);
- checklists for the start of regular activities such as transfer, loading and unloading;
- work permits for special not everyday activities;
- work procedures to record and repair irregularities found.
244. In addition to supervision during the operational activities, the installations have to be placed
in a maintenance, inspection, and management system in which every function of the
installation is maintained, inspected, and if necessary repaired with the frequency
determined.
11.2 Work permits
245. When work is outsourced, such as maintenance of installations, the responsibilities of the
client and contractor with regard to safety and environment have to be regulated by means of
a work permit.
The work permit at least contains a description of the work to be performed, the risks
attached to it, and the protective measures to be taken. A copy of the signed work permit is
with the client and present on the location of the work.
11.3 Periodical inspection and maintenance
11.3.1 In general
In addition to settings, corrosion is the most common degradation form that can affect tank
components. The metal tank is exposed to both external corrosion and internal corrosion (by
product and pollutions in the product).
In addition to these general forms of corrosion, the EEMUA publication No. 159 [Ref. 34]
describes the most common corrosion phenomena in and on storage tanks. This publication also
describes possible measures that can be taken to limit corrosion. Corrosion almost cannot be
prevented. The period of time in which corrosion occurs and the speed with which it jeopardizes
important tank components can be influenced.
The inspection regime described in the paragraphs hereinafter will contribute to it that tanks can
be used for their principal task for a long period of time.
246. Inspection and maintenance of the tank and appurtenances should take place in accordance
with an inspection program and maintenance program that have to be approved by the
competent authority.
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Explanation:
Depending on the applied standard or code when the tank is designed, the following
directives can be used for inspections and evaluation of the inspection results:
a. tanks designed in accordance with the standard BS 2654 [Ref. 22] or the standard NEN
EN 14015-1 [Ref. 70]:
- the volume of firewater that can be brought into the tank farm containment area in
one hour in accordance with the capacity required in the permit;
- EEMUA Publication No. 159 [Ref. 34];
b. tanks designed in accordance with the code API 650 [Ref. 4]:
- Code API 653 [Ref. 5];
- API Recommended Practice 575 [Ref. 3].
247. Independent from the code that applied during the new construction of the tank in question,
the rejection criteria per tank component referred to in the EEMUA Publication No. 159
[Ref. 34] can be used.
Explanation:
If there is degradation by for instance corrosion and/or setting, the rejection limits per tank
component apply, as they have been laid down in the EEMUA 159 document [Ref. 34].
11.3.2 Inspection of tanks
248. The inspection program at least has to contain the following:
A. Inspection of tanks and appurtenances
1. Inspection schedule
Tanks have to be inspected with a frequency agreed on with the competent authority. A schedule
has to be drawn up for the nature of the inspection activities, the methodology to be used, the
number of measurements and the period in which the inspections have to be performed, which
schedule requires the approval of the competent authority.
2. Inspection schedule tank floor (internal)
The inspection term of the tank floor can be based on:
a. A risk-driven methodology in conformity with paragraph 7.7 of the Dutch Soil Protection
Guidelines (“NRB”) [Ref. 82], section Soil Protection atmospheric aboveground storage tanks
(“Bo-bo guideline”);
b. The Probabilistic Preventive Maintenance methodology (PPM) in accordance with the
description of the EEMUA publication No. 159 [Ref. 34.]; Explanation:
The PPM methodology is based on two underlying methodologies:
- Risk Based Inspection (RBI);
- Reliability Centered Maintenance (RCM). c. A methodology developed by the company itself. This requires the approval of the competent
authority. Explanation:
If an inspection term is determined based on the NRB, one has to take into account the chance of and
the effect of the tank floor suffering a leak. A measure for the chance is the soil risk category in
accordance with the NRB. A measure for the effect is the nature of the product in the tank. See for
maximum inspection terms the NRB [Ref. 82].
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3. Inspection of tank wall and tank roof
The inspection of the tank wall and the tank roof and the inspection terms have to be determined in
accordance with one of the two following methodologies:
a. The PPM in accordance with the description of the EEMUA publication No. 159 [Ref. 34]; the
method in which the inspections have to be conducted and the necessary amount of
measurements have to be determined in accordance with the EEMUA publication No. 159
[Ref. 34];
b. A methodology developed by the company itself. This methodology requires the approval of
the competent authority. Explanation:
The methodology under a. corresponds with the methodology referred to above in point 2.b of the tank
floor inspection.
4. Inspection of seals
Seals of tanks with floating roofs should be inspected as to proper functioning and sealing with a
frequency agreed on with the competent authority. The inspection term and the inspection method
have to be on conformity with the EEMUA publication No. 159 [Ref. 34]. Deviations from it
require the approval of the competent authority.
5. Inspection of pressure vacuum air valves, air valves, and hinge bolts
Pressure vacuum air valves, air valves, and hinge bolts have to be inspected as to their proper
functioning with regard to closing and sealing, be maintained, and repaired, if necessary, with the
following frequency:
- within one year after installation of a tank for a product with which one has little or no
experience;
- within two years after installation of a new tank for a known product;
- subsequently with a frequency of at least once every four years after proper functioning has
been proven.
These activities have to be performed by the expert or expert organization accepted by the
competent authority. The competent authority should be able to inspect the report of the
inspection at all times.
Explanation:
The expert referred to does not have to be an external expert. Registration with and acceptance by the
competent authority remain a condition in all cases.
6. Inspection of shut-off valves
The shut-off valves have to be inspected with a frequency agreed on with the competent authority.
If leaks to the outside are found, measures have to be taken promptly to repair the leak. In other
cases, the shut-off valve can be repaired during the periodical maintenance of the tank.
7. Inspection of stairs, platforms, and the like
The condition of stairs, platforms, footbridges, railings, and the like has to be inspected once every
year.
8. Inspection of the grounding
The groundings have to be visually inspected as to reliability every year by an expert accepted by
the competent authority.
Explanation:
61
The expert referred to does not have to be an external expert. Registration with and acceptance by the
competent authority remain a condition in all cases.
9. Inspection and maintenance of instruments and protections
All components of the instruments and protections, including the level signal(s) and the
independent overfill protection that affects the inlet, have to be inspected periodically as to their
proper functioning, and be maintained. Inspection and maintenance have to be risk based and
adjusted to the reliability data of the instruments and protections.
The methodology to be applied by the companies has to contain the following elements:
- Mark the level signals and overfill protection as critical
- Set up reliability object and inspection frequency in relation to the safety risk and failure data
of the components
- Set up an inspection and maintenance plan for these components
- Set up a system for documentation and a filing system of inspection and maintenance
activities to the components
- Malfunction analysis (inter alia in connection with functional failure) that may lead to
adjustment of inspection and maintenance plan.
Explanation:
The necessity of the presence and the manufacture of instruments can be determined by the
results of a so-called Criticality Study, using a criticality matrix in accordance with the Risk
Based Inspection (RBI) method in combination with IPF (Instrument Protective Function)
study. With the study results, the necessity of more or fewer protection instruments can be
determined. The study is tailored to the specific situation of protection of tanks and is
consequently more suitable than a general rule.
The test and inspection frequency can depend on the type and manufacture of the instruments
in combination with the result of the tests. In this manner, the test frequency can be reduced to
at least once every five years. If an operator wants to apply RBI, the method has to be
submitted to the Technical Commission for pressure appliances.
B. Inspection of heating equipment
For major maintenance to the tanks, the heating elements of critical parts of the tanks have to be
inspected as to corrosion and be pressure-tested. If there is a reason in the interim to assume the
element leaks, measures promptly have to be taken to repair the leak (by blocking off, if
necessary).
When substances are stored that can solidify or crystallize by environmental temperature, an
inspection program has to be available and performed to the heating system of the tank.
C. Inspection of the product pipe system
At least once every year, inspections have to be conducted of:
- unacceptable settings, if any, of the product pipe system;
- functioning of shut-off valves and appurtenances of the product pipes;
- any leak phenomena of the seals of shut-off valves and flanges of product pipes.
If corrosion can occur in the system (for instance because of slop drain pipes containing water or
because of the nature of the product), an examination of the pipe system has to be performed
simultaneously with the ultrasonorous examination of the storage tanks to which product pipes
are attached. Data and results have to be recorded in a logbook or equipment registration card.
62
11.4 Maintenance fire safety facilities
The maintenance system
249. There has to be a maintenance and test system, approved by the Fire Department.
Explanation:
A reference framework for it is the document Fire System Integrity Assurance of the Oil and Gas
Producers Association. The NFPA has design criteria and requirements related to maintenance,
inspection and testing for may specific fire extinguishers.
This system at least has to contain:
- a description of the parts belonging to the fire control, or firefighting of hazardous
substances. Think in this connection of standpipes, monitors, sprinkler and deluge
installations, pumps, etc.;
- a description of the periodical tests and who performs them (internally with position, or
externally by company);
- the manner in which the test results are registered and retained.
The Fire Department may set further requirements.
250. The operator has to carry out the approved maintenance and test system.
Explanation:
General parts of the firewater system, such as pumps, pipes, and aboveground fire hydrants at least
have to be inspected, maintained, and tested in accordance with the NFPA 25 [Ref. 76], unless a
competent authority sets higher requirements for this purpose.
251. At least once every year an inspection has to be conducted in which all fire extinguishers
and fire alert facilities are inspected as to their readiness for use.
252. The firewater system has to be rinsed once every year with an efficient rinsing program to
remove accretion. The rinsing program has to be contained in the inspection, maintenance
and test system.
253. Once every three years, a capacity test of the aboveground fire hydrants is conducted by a
company recognized by the competent authority, on which occasion it is determined
whether they meet the capacity requirement of 360 m2/h for three aboveground fire hydrants
set in paragraph 8.3.3.
The results of this inspection have to be recorded in a register that has to be retained during
the service life of the equipment in question.
11.5 Waste
254. Waste that is not reclaimed, treated, processed, or destroyed, has to be removed from the
establishment.
255. Spilt substances have to be neutralized or absorbed as soon as possible. For this purpose,
adequate means of absorption or neutralization have to be present in or near the storage. The
nature and amount have to be adjusted to the nature of the substances and the nature of the
storage. Used means of absorption and neutralization have to be treated as hazardous waste.
11.6 Documentation and document management
63
256. A registration system or logbook has to be kept of each tank.
257. All certificates, measurement reports, and written results of inspections regarding the tank
installations and appurtenances, referred to in any section of this directive, have to be present
at the establishment.
258. The registration system has to be shown to inspecting officers of government agencies
involved upon request at all times.
259. The system has to contain at least the following data:
- tank number and location;
- year of construction;
- measurements and nominal capacity;
- building specifications and list of material types, thickness and quality*;
- measurements and nominal capacity of tank foundation and tank farm containment area;
- building specifications and list of material types of tank foundation and tank farm
containment area*;
- starting points for the maintenance system;
- data of repairs, if any;
- data of changes, if any;
- data of inspections;
- dates of inspection and re-inspection;
- specification of inspection and inspection results (measuring results, photographs);
- specification of the organization that has conducted the measurements and inspections.
*If these data are missing, the data from the Fit-for-purpose analysis/calculation are meant
by this.
64
12. Change management
12.1 Introduction of changes (organizational and technical)
260. The operator has to record the manner in which action is taken in changes. These are the
establishment and application of procedures for planning and change of the organization, the
establishment or parts hereof, or of the design of a new process or working procedure.
261. Each intended change of the organization or of installations or parts hereof has to be
evaluated in a structured manner as to the possible consequences hereof. If a safety study or
risk inventory was conducted for the original installation, it has to be conducted again for the
changed situation. The consequences of the change for the scope and characteristics of the
various accident scenarios and incident control are analyzed and recorded.
262. Given the expected service life of the installations, the user has to test the properties of
products and parts, meanwhile possibly changed in composition, to the original design
criteria of the installation.
12.2 Reporting changes
263. Changes that affect the environment and (fire) safety have to be adequately and timely
communicated to the authorities involved and adjacent companies, if any. Temporary
changes such as maintenance or malfunction, in particular of safety critical equipment, have
to be reported to the competent authority in time, and if related to the incident control, also to
the Fire Department in writing. On this occasion, the substitute equal measures taken are also
specified.
12.3 Implementing consequences of changes
264. When implementing changes, the consequences hereof for the scope and characteristics of
the different accident scenarios and incident control have to be analyzed and recorded.
265. If necessary, additional measures are taken, such as adjustment of the operational plans or the
incident control system.
65
13. Termination and putting out of operation
If a tank of part of an installation is taken out of operation for an indefinite, longer period of time,
the maintenance program can be adjusted to it. Maintenance can then be focused on maintaining
the mechanical integrity of the construction, at least until the definitive removal or putting into
operation again of the tank or part of an installation takes place.
266. The tank and appurtenances and/or the part of the installation has to be left and kept safe for
humans, the environment, and other parts of the installation.
The tank and appurtenances and/or the part of the installation of any parts of the installation
still in use have to be separated by placing blind flanges in the connecting pipes.
267. Slurry, scrapings, waste, auxiliary substances, and rests of product are removed and suitably
disposed of.
268. When changing the status of use of the tank (putting out of operation, putting into operation
again, removal) and/or part of the installation, the relevant risks and the accompanying
relevant environmental and integrity aspects have to be identified by a systematic risk
inventory and risk evaluation.
269. The tank data are retained at least:
- during the statutory terms;
- as long as the tank has not been removed definitively;
- as long as the consequences of an incident, if any, during the phase of use or removal of the
tank have not been fully dealt with.
270. When a definitive decision is made to demolish a tank (or a series of tanks), the owner of the
tank(s) and the contractor hired for this purpose have to follow the directives as described in
the EEMUA 154 [Ref. 33].
271. The mutual responsibilities (between owner and contractor) used in this document and the
requirements set for the demolition procedure to be drawn up have to be followed in full and
the demolition plan has to be tested to the actual condition of the tank(s). A weakened
corroded construction requires far-reaching safety measures and the contractor has to be fully
informed hereof.
66
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6. API recommended practice 752; Management of hazards associated with location of process
plant buildings.
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refrigerated, 1999.
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tank fires, 1991.
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67
28. CPR 9-3, liquid petroleum products, aboveground storage in large installations, Sdu Publishers
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32. DIN 4119 “Oberirdische zylindrische Flachboden Tankbauwerke aus metallischen
Werkstoffen: Gindlagen, Ausführung, Prüfungen” (Teil 1); “Berechnung” (Teil 2)
33. EEMUA 154, Guidance to owners on demolition of vertical cylindrical steel storage tanks and
storage spheres, 2002.
34. EEMUA 159, Users guide to the maintenance and inspection of aboveground vertical
cylindrical steel storage tanks. Engineering Equipment and Materials Users Association,
Publication No. 159, London, third edition, 2003.
35. EEMUA 180, Guide for designers and users on frangible roof joints for fixed roof storage
tanks, 1996.
36. EEMUA 185, Guide for hot tapping in piping and other equipment.
37. EN 288-3, Welding procedure tests, 1992.
38. EN 45004/ISO 17020 “General criteria for the functioning of various types of institutes
conducting inspections”.
39. EN-IEC 60079-10, Electrical equipment for places where there may be a risk of gas explosion,
2003.
40. EN NEN 50110, Operations of electrical installations, 1998.
41. European Directive 67/543/EEC on characterizing hazardous substances.
42. Institute of Petroleum (IP), section 5, Bulk storage and Transfer facilities.
43. Institute of Petroleum (IP) Refinery Safety Code part 3.
44. Institute of Petroleum (IP):
IP Code No. 2: Marketing Safety Code
IP Code No. 3: Refining Safety Code
IP Code No. 19: Model Code of Safe Practice
45. Inspection procedure and safety regulations for gas installations with industrial buyers of the
“NV Nederlandse Gasunie”, information No. 7, edition 1988.
46. KWS 2000, Infomil, VNG publishers The Hague, 1997.
47. Model Building Ordinance, VNG, 2002.
48. Netherlands emission directives (NeR), Infomil The Hague, 1992.
49. NEN 1010, Safety provisions for low-voltage installations, 2003.
50. NEN 1014, Lightning protection, 1992.
51. NEN 2535, Fire safety of buildings – Fire detector installations – System and quality
requirements and development guidelines, 1996/A1:2002.
52. NEN 3011, Safety colors and signs, 1986.
53. NEN 3125, Electrical material for places where there may be a risk of explosion, 1980.
54. NEN 3140, Operations of electrical installations – Additional Netherlands provisions for low-
voltage installation, 1998.
55. NEN 3204, Flashpoint determination according to Abel-Pensky.
56. NEN 3205, Preferred test temperatures, 1996.
57. NEN 3650:
NEN 3650-1, Requirements for pipeline systems, Volume 1, In General 2001.
NEN 3650-2, Requirements for pipeline systems, Volume 2, steel: In General 2001.
NEN 3650-C1, Requirements for steel pipeline systems, 1996.
68
58. NEN 6901, pretreatment for the lining of steel pipes and fittings to be installed underground,
NNI, 1976.
59. NEN 6902 External cladding with PE of steel pipes and fittings to be installed underground,
1986.
60. NEN 6905, external epoxy claddings of steel pipes and fittings to be installed underground,
NNI, 1983.
61. NEN 6907, external cladding with asphalt bitumen of steel pipes and fittings to be installed
underground, and the installation hereof, NNI, 1979.
62. NEN 6910, Cathodic protection of onshore pipelines and constructions of metal, 1983.
63. NEN 6912, Cathodic protection of onshore pipelines and constructions of metal.
64. NEN 6068, Determining the resistance to fire transfer and fire transfer between spaces, 2001.
65. NEN EN 12, Petroleum products, Determining the vapor pressure according to Reid; Wet
method 1994 (replaces NEN 928:1970).
66. NEN EN ISO 2719, Determination of flash point, 2002.
67. NEN EN 10204, Products of metal – types of inspection documents, 2004.
68. NEN EN 12798, Additional requirements transportation hazardous substances. Previously:
NEN 2726, quality requirements for the transportation of hazardous substances and the care
for the environment and the safety of the staff.
69. NEN EN ISO 13736, Petroleum products and other liquids – Determination of flashpoint,
1997.
70. NEN EN 14015-1, Specifications for the design and manufacture of vertical, cylindrical,
aboveground, welded metal tanks built on site with a flat floor for storage of liquids at
environmental temperature and higher.
71. NFPA 11, Standard for Low-, Medium-, and High-Expansion Foam, 2002.
72. NFPA 14, Standard for the Installation of Standpipe and Hose Systems.
73. NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection.
74. NFPA 22, Standard for Water Tanks for Private Fire Protection.
75. NFPA 24, Standard for the Installation of Private Fire Service Mains and Their
Appurtenances.
76. NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-based Fire
Protection Systems, 2002
77. NFPA 30, Flammable and Combustible Liquids Code.
77.a.NFPA 69, Standard on Explosion Prevention Systems.
78. NFPA 77, Recommended Practice on Static Electricity.
79. NPR 6903, external cladding with PE of steel pipes and fittings to be installed underground,
and the installation hereof, NNI, 1986.
80. NPR 6911, external cladding with asphalt bitumen of steel pipes and fittings to be installed
underground, and the installation hereof, NNI, 1983.
81. NPR 7910-1, Division into danger zones with regard to risk of explosion, based on NEN EN
IEC 60079-10, 2002. NPR 7910-1: 2001, Division into danger zones with regard to risk of gas
explosion (previously P 182 of the Ministry of Social Affairs and Employment).
82. NRB, Netherlands Soil Protection Guidelines for business sites, 2001.
83. Pressure Equipment Directive, (97/27/EC), 1999.
84. Directive 97/23/EC of the European Parliament and the Council of May 29, 1997 (Pressure
Equipment Directive, PED).
85. Ship/shore safety checklist and Guidelines Sdu Publishers, 2000 version.
86. Standard requirements book province of Zuid-Holland.
87. “Technische Regeln für brennbare Flüssigkeiten”, TRbF 111, No. 4.
88. Safety checklist for ocean-going tankers, Staatsuitgeverij, edition 1995.
89. Association Netherlands Chemical Industry, VNCI, http://www.vnci.nl
69
90. Information sheet V23, Risks of static electricity, Health and Safety Inspectorate.
91. Provisional guideline for protection of one-burner installations burning on oil/natural gas with
a maximum load exceeding 600 kW, by the taskforce “Stoken” of the Technical Commission
for pressure appliances (TCTD) of the Directorate-General of Labor of the Ministry of Social
Affairs, edition August 1975.
92. Environmental Management Act.
93. Chemical Substances Act (“Wms”), 1985.
94. Dangerous Equipment Act, 2003.
95. Pressure Equipment Commodities Act Decree, 2001.
96. NEN EN 10025, Hot-rolled products of construction steel, 2004.
70
Annex A: Additional recommendations for tank foundations
Before the construction, an expert should have conducted a soil-mechanical study and reported on
it. This also applies if the tank is placed on a risen foundation.
Explanation:
The soil-mechanical study includes the following:
1. Information on the composition and permeability of the soil layers, horizontally and vertically;
2. Study of the properties of the layers to facilitate a responsible setting prognosis.
Based on existing local experience or information, the above may be deviated from in this sense, that in
consultation between the soil-mechanical consultant and an inspection institute accepted by the license-
granting agency, the soil study can be limited.
The study has to include sufficient soil-drilling tests to give a clear understanding of the
composition of the most compressible layers. As a guideline, the numbers of soil-drilling tests of
figures A.1 and A.2 can be adhered to (EEMUA):
[circle]
25 m ≥ tank diameter < 50 m
Max. spacing cpt’s ± 25 m
Spacing periphery ± 19 m
Figure A.1: number of soil-drilling tests for tanks with a diameter between 25 and 50 m.
[circle]
Tank diameter > 70 m
Max. spacing cpt’s ± 25 m
Spacing periphery ± 31 m
Figure A.2: number of soil-drilling tests for tanks with a diameter > 70 m.
(Note: for tanks with a diameter < 12.5 m the number of soil-drilling tests is 5)
The predicted settings and setting differences have to provide a picture of the expected behavior of
the tank wall and tank floor. In case of a spacing prognosis per examination point, one has to take
into account pre-loads, if any, time of putting into operation, and factors affecting this prognosis.
Explanation:
Furthermore, the report has to pay attention to:
- chance of pressing out of soft layers;
- filling velocity during tank water test;
- average toppling of the tank in a plane;
- setting differences compared to the average plane of toppling;
- the permeability of the soil for liquids.
For putting the tank into operation one has to pay attention to:
- the control of the water tensions in more compressible layers during filling;
- the expected setting behavior in the period of use;
- the water control of foundation and tank farm containment area.
The tank foundation has to be designed as a flexible foundation that is strong enough to:
- be able to absorb the deformations of the subsoil so that the deformations of the tank floor
remain within reparable limits;
71
- distribute possible uneven foundation pressure.
Tank foundations can be designed within the five alternatives referred to in the EEMUA No. 183
Directive.
Rigid foundations (concrete plate foundations and/or rigid elements in, next to and under the tank)
have to be avoided.
Under some conditions, soil improvements have to be performed:
- to create a foundation with sufficient strength;
- to reduce considerable, differential settings expected along the periphery of the tank and
between the tank wall and the center of the tank floor.
If soil improvements have to be performed, it has to take place above the groundwater level at all
times. The minimum amount of soil to be excavated can be derived from figures A.3 and A.4:
[drawing]
Figure A.3: soil improvement on an equal level
[drawing]
Figure A.4: soil improvement on an unequal level
If risen foundations are used, the height of the foundation above the ground level of the tank farm
containment area has to be at least 0.6 m, while the – long-term – setting to be expected has to be
added to this value. In all other cases, the foundation height can be limited to approximately 0.1 m.
Foundations have to be made with one shoulder that extends outside the tank diameter. The
minimum width and the gradient of the shoulder depend on several aspects, such as:
- the height of the tank;
- the density of the tank content;
- the type of tank foundation (complete sand foundation or annular ring of crushed stones etc.);
- the slope of the shoulder;
- the height of the risen foundation.
Unless the circumstances hinder it, the shoulders of risen foundations have to be made in
accordance with the tables below, while in both tables the parameters are:
H = tank wall height [m];
S = width of the shoulder measured from the tank wall/floor connection [m];
T = height risen foundation for the water test [m].
Table A.1: Risen foundations without annular section of crushed stones
H
[m]
S at least
[m]
T at least
[m]
10 1.00 1.20
20 1.50 1.00
72
Table A.2: Risen foundations with annular section of crushed stones
H
[m]
S at least
[m]
T at least
[m]
10 1.00 1.50
20 1.50 1.00
The slope of the shoulder cannot be chosen above the gradient value of 1:1.5, within the
measurement of S. Outside it, this slope can be a gradient of 1:10.
The body of the tank foundation has to be built of clean granular material preferably meeting the
following requirements:
- cannot be crushed;
- high friction properties: φ > 35o; c > 0;
- low compression possibility: C4
10 > 500;
- low salt content: ≤ 10% m/m;
- drainage possibility: k ≥ l x 10-4
m/s;
- provides resistance against:
raining in;
oxidation;
chemical changes;
changes in mechanical properties;
- easy to compact.
Explanation:
Well-compacted sand amply meets these conditions, provided that the chemical and mechanical stability of
the minerals in it meet aforementioned requirements.
To prevent capillary rise of the groundwater, the upper 200 mm layer of the foundation has to consist of
coarse sand.
A foundation ring for the foundation shoulder and the part of the foundation under the wall/floor
connection of the tank that consists of crushed stones is to be preferred over a foundation entirely built of
sand. This material is stronger and provides better resistance against corner setting and is better resistant
against loads during the initial construction of the tank.
A concrete ring-beam foundation will preferably not be used. Only if the tank has to be anchored for the
absorption of the internal (high) pressure or to absorb the toppling moment by wind loads (only in case of
slim tanks) can this type of foundation be opted for. In that case, special attention is to be paid to the
compaction of the sand layers within this concrete ring so that no excessive setting can occur, which may
be hazardous to the floor/wall connection of the tank.
In all cases a top layer has to be installed on the foundation of a bitumen/sand mixture (sand/oil
mixture for tanks operating at over 70oC) of at least 0.05 m. The object of this top layer is:
- to act as a protective layer against corrosion caused by water and chemicals that can be
present in the foundation;
- to let the distribution of the loads from the tank floor to the foundation take place evenly;
- to protect the foundation during the construction of the tank;
- to facilitate thermal expansion of the tank floor.
Explanation:
This sand/bitumen layer can for instance consist of the following composition:
73
- 96% (m/m) sand for tank foundation;
- 4% (m/m) bitumen 45/60.
The top layer of the foundation will have to extend at least 0.15 m outside the tank floor.
Explanation:
The part of the foundation shoulder situated outside it can be finished with every suitable substance that
prevents erosion from occurring. An asphalt or concrete layer or a bitumen/sand layer under which a geo-
textile cloth has been placed meets this requirement.
The part of the shoulder directly at the tank wall/floor connection should have a gradient that
prevents (rain)water or pollutions from being able to penetrate to under the tank floor.
74
Annex B: Additional recommendations for tank constructions
The below requirements are supplementary to the codes referred to in Chapter 6.1.
Soil configuration
Annular ring sections
Contrary to what was stated in aforementioned codes (see Chapter 6.1), the floor of each tank,
independent of the diameter of the tank, has to be made at all times with an annular ring section
the welding joints of which have to be made with butt joints. The butt joints can also have backup
strips.
Concave, convex, or flat floors
If concave or convex shaped floors are chosen, the maximum gradient cannot be more than 1 mm
on a 120 mm radial distance. In all cases, the maximum difference in height between the center of
the tank and the foot of the floor outside the tank wall cannot be more than 300 mm. Tanks
operated at temperatures > 70oC are preferably made with a cone-up floor configuration.
Wall plates
All tank wall plates at least have to meet the following requirements:
- Wall plates have to be rolled in the correct tank curvature. The vertical ends of wall plates for
tanks with a diameter < 25 m have to be pre-formed in the correct tank curvature.
- The minimum thickness provided, after rolling, cannot be under the minimum value
calculated (no negative tolerances allowed);
- The profile of all tank wall plates should have a maximum tolerance of +/- 2 mm in length.
The maximum tolerance in height is +/- 1 mm. Moreover, the difference between the
diagonals, measured along the rectangular, made by lines that have been drawn 50 mm from
the ends of the plate, cannot deviate more from each other than 3 mm.
- For all other construction tolerances, reference is made to the codes and standards referred to
in Chapter 6.1.
Tank heating system
If the tank has a tank heating system, a system is required which regulates and controls the heat
supplied.
Explanation:
This system serves to bring and keep the tank content at the correct temperature and can be operated locally
and by remote control.
The heating system has to be equipped with an alert that is activated when the set maximum heat
supplied and temperature of the tank content is exceeded.
A solid attachment and support of the heat pipe systems in the tanks is required in connection with
sometimes violent liquid movements in tanks during filling and/or homogenizing of the content.
Materials
Only materials approved in accordance with the standards referred to in Chapter 6.1 can be used,
provided that they meet the following additional requirements:
- All plate materials have to meet NEN EN 10025;
75
- For all plate materials, maximum values apply for certain alloy elements in conformity with
the following table B.1;
- For flanges and special parts, the carbon content may deviate to a maximum of 0.25%;
Table B.1: Maximum values chemical composition plate materials
Plate material Chemical composition
C 0.23% max
Mn 1.50% max
Si 0.40% max
P 0.04% max
S 0.04% max
P + S 0.07% max
V 0.10% max
Nb 0.04% max
Nb + V 0.10% max
- The percentage of carbon equivalent determined in accordance with the following formulas
cannot exceed the values mentioned in same:
For materials of which only the carbon (C) and the manganese content (Mn) are
specified:
Mn
Ceq = C + 6 ≤ 0.42%
For materials of which all alloy elements have been specified, per charge, the
following formula has to be complied with:
Mn Cr + Mo + V Ni + Cu
Ceq = C + 6 + 5 + 15 ≤ 0.43%
All materials used in construction parts that bear loads have to be delivered per charge with at least
a 3.1.b certificate in accordance with NEN EN 10204. All auxiliary materials and materials used in
constructions that do not take on loads can be delivered per charge with at least a 2.2 certificate in
accordance with NEN EN 10204.
In addition to aforementioned requirements, plate materials for the tank wall and tank floor have to
be tested at the location of the wall/floor connection (annular ring) as to tenacity in accordance
with the Charpy V test method. The tenacity values then have to be fixed at the test temperatures
indicated in table B.2 in the 4th
column. Also, the average of three tests cannot exceed the
minimum value indicated in the 3rd
column of the following table B.2, and one value of the three
tests cannot be lower than 70% of the specified value of the table B.2:
Table B.2: Minimum Charpy V values and test temperatures
Plate thickness
[mm]
Tensile strength
[N/mm2]
Minimum Charpy V
value [J]
Test temperature
[oC]
≤ 12.5 Charpy V test not required
>12.5 ≤ 430 27 +20
>12.5 >430 ≤ 490 41 -5
>12.5 >490 41 -15
76
Construction requirements
Periphery tolerances wall plates
Before the welding at the lowest wall ring plates begins, a measurement has to show that the setup
of the plates in the periphery direction is such that after completion of the welding, the setup of the
tank wall at least meets the following tolerances. If tolerances are expected that indicate that these
measures are exceeded, the plates have to be set up again before the welding begins.
The tank wall has to be set up in such a manner that there is a minimal difference between the
circle shape of the lower ring plates of the tank wall and that of the upper. Correction by cutting
into the tank wall plates is not allowed.
After the first tank wall ring has been assembled and welded completely, the internal radius,
measured horizontally from the center of the tank to each point of the tank wall, cannot deviate
more than indicated in the following table B.3:
Table B.3: Maximum deviation from the internal radius of tank wall plates
Tank diameter
[m]
Maximum deviation from the nominal
internal radius [mm]
≤ 12.5 13
>12.5 ≤ 45 19
>45 25
Support construction of the roof plates
Before the assembly of the roof support construction, the tank wall has to be inspected for unequal
setting in the periphery direction.
Explanation:
The unequal setting in periphery direction can cause oval shape of the tank wall at some places.
Every deviation of the tank wall has to be corrected before the trusses are positioned.
Temporary supports that are used for the assembly of the roof support construction cannot be
removed before the principal trusses and the webs and wind bracings have been attached
completely.
In case of domed roofs, the temporary central support portal cannot be removed before the radial
trusses, the webs and wind bracings have been attached completely and the roof plates have been
affixed to each other by tack welds. The positioning of the principal trusses has to be done
accurately so that deviations compared to the radial direction of the trusses are prevented.
The strength, rigidity and stability of temporary supports of the roof construction have to be
proven by calculations, while the maximum construction loads that can occur have been
calculated.
Tank wall tolerances
Verticality of the tank wall
After complete assembly/welding activities, the tank wall will not show larger vertical deviation
than the measurements as indicated in table B.4.
77
Table B.4: Maximum vertical deviation tank wall
Tank diameter
(m)
Maximum vertical deviation
≤ 12.5 1:400
>12.5 ≤ 30 1:350
>30 ≤ 45 1:300
>45 1:250
Explanation:
The measurement 1:400 means 1 mm leaning over on a tank wall height of 400 mm.
These tolerances apply to the entire tank wall and can also be used for the measuring of the
individual tank wall rings.
Local deviations of the periphery curvature
Local deviations of the tank curvature of the tank wall (horizontally and vertically) cannot be
higher than the following tolerances measured over a length of 2.5 m removed from the welding
joints (table B.5):
Table B.5: Maximum deviations of the periphery curvature
Plate thickness
[mm]
Maximum local deviation from the tank
curvature [mm]
≤ 12.5 16
>12.5 ≤ 25 13
>25 10
These deviations of the tank curvature will have to run equally over aforementioned length
without any sharp change in shape.
Tolerances at horizontal and vertical welding joints
At horizontal and vertical welding joints, the tank wall profile cannot show more deviations
compared to the tank curvature, than the following tolerances, measured over a length of 1 m
(table B.6).
Table B.6: Maximum deviation of tank wall profile at welding joints
Plate thickness
[mm]
Maximum deviation of the tank wall
profile at welding joints [mm]
≤ 12.5 10
>12.5 ≤ 25 8
>25 6
Tolerances for deviations of plates at butt joints
Plates that are connected to each other by butt joints accurately have to fit to each other and be
kept in position during the welding process. Deviations on the central line of the tank wall plates
cannot exceed the following tolerances (table B.7):
78
Table B.7: Deviations tank wall plates at the central line
Plate thickness, t
[mm]
Maximum deviation
the least value of:
of the central line
[mm]
Vertical welds ≤ 19 0.1 t 1.5
>19 0.1 t 3.0
Horizontal welds ≤ 8
(top plate)
0.2 t 1.5
>8
(top plate)
0.2 t 3.0
Top section of the tank wall
The tank wall has to be re-measured as to roundness before any wind girder(s) and roof support
constructions (in case of fixed roofs) or the primary or secondary wind girder(s) (in case of
floating roofs tanks) are assembled and welded.
Measurement deviations of a floating roof compared to the tank wall
After complete assembly and welding, the difference in the gap between the tank wall and the
outer rim plate of the floating roof cannot exceed 13 mm of the nominal gap in accordance with
the construction drawing.
At each height of the roof, other than the height at which it has been built, this difference in the
nominal gap cannot exceed ± 50 mm.
Bending tolerances of the annular ring of the floor construction after welding
It may occur because of the welding process of the two corner joints of the floor/wall connection
that the annular section bends upward. The maximum allowed bend of the annular section is 40
mm over a distance of 750 mm (5.3% gradient).
79
Annex C: Standards for tank installations
British Standards (BS)
1. BS 2654 British Standard Specification for Manufacture of vertical Steel welded non-
refrigerated storage tanks with butt-welded shells for the petroleum industry. British Standard
2. BS 3602
3. BS 3059
4. BS 1503
5. BS 1640
6. BS 1965
7. BS 1504
American Petrol Institute (API)
8. API RP 575 (Recommended Practice) Inspection of atmospheric and low-pressure storage
tanks, American standard 575, American Petroleum Institute, Washington
9. API 650, Welded steel tanks for oil storage. American standard 650, American Petroleum
Institute, Washington
10. API 651, Cathodic protection of aboveground petroleum storage tanks. American standard
651, American Petroleum Institute, Washington
11. API 653, Tank inspection, repair, alteration and reconstruction. American standard 653,
American Petroleum Institute, Washington
12. API 2517, Evaporative Loss from External Floating Roof Tanks, American standard 2517,
American Petroleum Institute, Washington
13. API 2519, Evaporation loss from internal floating roof tanks
“Deutsches Institut für Normierung” (DIN) (German Standardization Institute)
14. DIN 1629
15. DIN 17175
16. DIN 17100
17. DIN 2605
18. DIN 2606
19. DIN 17245
20. DIN 4119 “Oberirdische zylindrische Flachboden Tankbauwerke aus metallischen
Werkstoffen: Gindlagen, Ausführung, Prüfungen” (Teil 1); “Berechnung” (Teil 2); German
“Nederlands Normalisatie Instituut” (NEN) (Netherlands Standardization Institute)
23. NEN EN 14015-1, Specifications for the design and manufacture of vertical, cylindrical,
aboveground, welded metal tanks built on site with a flat floor for storage of liquids at
environmental temperature and higher
24. NEN 1010, Safety provisions for low-voltage installations
25. NEN 1014, Lightning protection
26. NEN 3204, Flashpoint determination according to Abel-Pensky
27. NEN 3205, Flashpoint determination according to Pensky-Martens
28. NEN 3850, Technical bases for the calculation of building constructions – General section and
loads
29. NEN 6902, External cladding with PE of steel pipes and fittings to be installed underground
30. NEN 6910, External cladding with (asphalt) bitumen of steel pipes and fittings to be installed
underground
31. NEN 6912, Cathodic protection of onshore pipelines and constructions of metal
80
32. NEN 7089, Oil separators and catch basins – division into types, requirements and test
methods
33. NEN EN 10025, Structural steel
American Society for Testing and Materials (ASTM)
34. ASTMA 106
35. ASTMA 105
36. ASTMA 181
37. ASTMA 234
38. ASTMA 216
Engineering Equipment and Materials Users Association (EEMUA)
39. EEMUA 154, Guidance to owners on demolition of vertical cylindrical steel storage tanks and
storage spheres, 2002
40. EEMUA 159, Users guide to the maintenance and inspection of aboveground vertical
cylindrical steel storage tanks. Engineering Equipment and Materials Users Association,
Publication No. 159
41. EEMUA 180, Guide for designers and users on frangible roof joints for fixed roof storage
tanks
42. EEMUA 183, Guide for the prevention of bottom leakage from vertical, cylindrical, steel
storage tanks. Engineering Equipment and Materials Users Association, Publication No. 183
National Fire Protection Agency (NFPA)
43. NFPA 30 Flammable and combustible liquid code
Evaluation guidelines (BRL’s)
44. BRL-K 636 Overfill protections for storage installations for liquid petroleum products
45. BRL-K 779 Internal lining on steel tanks for flammable liquids
46. BRL-K 5251 Concrete oil separators and catch basins
47. BRL-K 5253 Oil separators in cast iron of sheet steel
48. BRL-K 19001 KIWA NV has drawn up an evaluation guideline for the process certification of
new construction and repair of single-wall, vertical, cylindrical, steel storage tanks with flat
floor for aboveground atmospheric storage of liquids
Miscellaneous
49. ANSI B/16.5 (flanged joints)
50. ASA 150 (flanged joints/shut-off valves)
51. VDI 3482 Sheet 2 and 3
52. VDI 3481 Sheet 1 and 3E
53. ADNR regulations (loading/unloading of tankers)
54. Rijnvaart Police regulations (loading/unloading of tankers)
55. VBG (Transportation of Hazardous Substances over the Inland Waterways) regulations
(loading/unloading inland navigation tankers)
81
Annex D: Distance tables from the codes of the Institute of Petroleum (IP) (ref.
44)
Placement and distances for aboveground tanks for storage of products of classes 1, 2, and 3
Source: IP Code 19, Model Code of safe practice, Table 3.1
(These distances have to be used in connection with the required protection level. The distances
may be deviated from, provided that suitable fire-protection facilities and measures have been
designed.)
Tank type Part of installation concerned Recommended minimum distances
Tanks with
1 between tanks within a group of small tanks only to be determined by considerations of
construction, maintenance and operations
fixed roof,
aboveground,
2 between a group of small tanks as referred
to in clause 3.4.2.4.1 of this IP Code
15 m
including
tanks with
3 between a group of small tanks and a tank
outside the group
at least 10 m
the distance does not have to exceed 15 m
internal
floating roof;
horizontal
cylindrical
tanks
4 between tanks not part of a group of small
tanks
The distance has to be the smaller of:
1) half the diameter of the largest tank
2) the diameter of the smallest tank
3) 15 m
but never smaller than 10 m
maximum 15 m
5 between a tank and a filling point, filling
installation or a building without possible
ignition source
14 15 m, but in agreement with the competent
15 authority the distances may be reduced to
16 no less than 6 m in case of small tanks
6 between a tank and the boundary of the
site, a non-danger zone, or a stationary
ignition source on ground level
15 m
Note 1:
For tanks higher than 18 m, it may be necessary to consider whether aforementioned distances
have to be increased in connection with the height of the tank.
Note 2:
Tanks with an internal floating roof can be considered to be tanks with a fixed roof for the
determination of the place and the distances.
Tanks with
1 between tanks within a group of small tanks only to be determined by considerations of
construction, maintenance and operations
floating roof
2 between two tanks with floating roof
10 m for tanks with diameter of 45 m max
15 m for tanks with diameter of over 45 m
The tank with the largest diameter
determines the distance. For crude no less
than 10 m, but a distance of 30% of the
diameter of the tank is recommended
without upper limit.
3 between a tanks with a floating roof
and a tank with a fixed roof
The distance has to be the smaller of:
1) half the diameter of the largest tank
2) the diameter of the smallest tank
3) 15 m
but never smaller than 10 m
maximum 15 m
4 between a tank with a floating roof and
a filling point, filling installation or a
building without possible ignition source
10 m
82
5 between a tank and the boundary of the
site, a non-danger zone, or a stationary
ignition source on ground level
17 15 m
18
Note 3:
For tanks with a diameter exceeding 18 m, see note 1.
Note 4:
Tanks with a floating roof with an external metal domed roof that expands over the entire roof
surface can be considered a tank with a fixed roof for the determination of the placement and the
distances.
Distances between tanks for the storage of petroleum products of classes 1, 2, and 3 in
refineries
Source: IP Code No. 3: Refining Safety Code, Table 5.1
Parts of installation concerned Tank roof type Recommended minimum distance
1 Within a group of small 1 tanks fixed or floating only to be determined by considerations of
construction, maintenance and operations
2 Between a group of small tanks and
another group of small or other larger
tanks
fixed or floating to be determined by the size of the
largest tanks, with a minimum of 10 m
(see 3)
3 Between adjacent (not small) tanks a) fixed
b) floating
50% of the diameter of the largest tank,
but at least 10 m and at the most 15 m.
30% of the diameter of the largest tank,
but at least 10 m and at the most 15 m.
4 Between a tank and the interior crest line
of the circumvallation
fixed or floating 50% to 100% of the height of the tank
Access around the tank
5 Between each tank of a group of tanks
and the interior crest line of the
adjacent dike
fixed or floating At least 15 m
6 Between a tank and the boundary of
the site
fixed or floating At least 30 m
7 Between the interior crest line of the
dike and the boundary of the site
or to a stationary ignition source on
ground level
- At least 15 m
8 Between a tank and the zone boundary
of a processing installation
fixed or floating At least 30 m
9 Between the interior crest line of a dike
and the zone boundary of a processing
installation
- At least 15 m
1.
Tank with a diameter of 10 m max [Ref. 67].
83
Placement and distances for aboveground tanks with fixed roofs for storage of liquid fuels of
classes 1, 2, and 3 in installations
Source: IP Code No. 2: Marketing Safety Code, Table 3.1
Parts of installation concerned Recommended distances
1 Between groups of small tanks 15 m
2 Between groups of small tanks and a tank outside the
Group
15 m
3 Between tanks that are not part of a group of small tanks the smaller distance of:
1) half the diameter of the largest tank
2) the diameter of the smallest tank
3) 15 m
but never smaller than 10 m
4 Between a tank and a filling point, filling installation,
or a building
15 m
5 Between a tank and the boundary of the site,
a non-danger zone, or a stationary ignition source
15 m
Placement and distances for tanks with floating roofs for storage of liquid fuels of classes 1
and 2 in installations
Source: IP Code No. 2: Marketing Safety Code, Table 3.2
Parts of installation concerned Recommended distances
1 Between two tanks with a floating roof 10 m for tanks with diameter of 45 m max
15 m for tanks with diameter exceeding 45 m
The tank with the largest diameter determines
the distance
2 Between a tank with a floating roof and a tank with
a fixed roof
The distance has to be the smaller of:
1) half the diameter of the largest tank
2) the diameter of the smallest tank
3) 15 m
but never smaller than 10 m
3 Between a tank with a floating roof and a filling point,
filling installation or a building without possible
ignition source
10 m
4 Between a tank with a floating roof and the boundary
of the site, a non-danger zone, or a stationary ignition
source
19 15 m, but in agreement with the competent
20 authority the distances may be reduced to
no less than 6 m in case of small, vertical
or horizontal, cylindrical tanks
84
Placement and distances for aboveground tanks for storage of liquid fuels of classes 1, 2, and
3 in depots
Source: IP Code No. 2: Marketing Safety Code, Table 3.3
Parts of installation concerned Recommended distances
1 Between tanks with a diameter of 10 m max or a
height of 14 m max
in conformity with the conditions of
construction and keeping in operation
2 Between tanks with a diameter exceeding 10 m or a
height exceeding 14 m
The distance has to be the smaller of:
1) half the diameter of the largest tank
2) the diameter of the smallest tank
3) 15 m
but never smaller than 10 m
3 Between a tank and a filling point, filling [word missing;
translator] or a building
21 15 m, but in agreement with the competent
22 authority the distances may be reduced to
no less than 6 m in case of small, vertical
or horizontal, cylindrical tanks
4 Between a tank and the boundary of the site,
the depot, a non-danger zone, or a stationary ignition
source
23 15 m, but in agreement with the competent
24 authority the distances may be reduced to
no less than 6 m in case of small, vertical
or horizontal, cylindrical tanks