Who are we?

S&S Northern Ltd is a family

business established in 1995.

We design, manufacture and sell gas controls

throughout the UK, Europe, Australia and USA.

With offices in Essex and Lancashire, we offer

nationwide coverage for technical backup.

We specialise in gas controls for

Boiler House Applications, Laboratories,

and Commercial Kitchens.

Where have our systems

been installed?

Topics of the CPD

Boiler House Applications

BS6644

BB100 – Fire Safety in Schools

IGEM/UP/1A – Edition 2

IGEM UP2 – Edition 3

School Science Labs and Food Technology

IGEM/UP/11 Gas Proving in Classrooms

BB101- CO2

Monitoring in Teaching Areas

Topics of the CPD

Topics of the CPD

Commercial Kitchen Regulations

BS6173:2009

IGEM UP/19

HSE, DW172 and CEDA Guidance on Solid

Fuel Appliances in Catering Establishments

Boiler House Applications

There are 3 levels of recommendation for

Gas Safety procedures in boiler house applications.

• Gas Isolation (BS 6644)

• Gas Detection (BB100)

• Gas Proving and Detection

(IGEM UP/1A Edition 2)

Boiler House Applications –

Gas Isolation

BS6644 states that a means of gas isolation must

be incorporated at the entrance to the boiler room

This can be a manually operated valve

If it is not possible or practical to fit a manually

operated valve in an easily accessible position,

an Electronic Control Valve (ECV) can be fitted

with an emergency knock-off button

Drop weight type valves are no longer suitable

for fitting to gas systems as they do not meet the

requirements of BS EN161. Existing systems with

these fitted should be marked up as “AT RISK”

This is also covered in IGEM UP2 / Edition 3

Heat Detectors or Fusible Links are often

installed to isolate the fuel supply in the event of

a fire

Boiler House Applications –

Gas Detection

BB100 (Building Bulletin 100 – Design for Fire

Safety in Schools) section 3.1.8 refers to boiler

houses in schools

It considers boiler rooms to be high risk

It states the following is required for new schools

or where an existing boiler room

is being upgraded

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The document states that a boiler house attached

to the main school building should be fitted with

combustible gas and carbon monoxide detection

BB100 also states that the gas detection system

should both raise an alarm and isolate the fuel

supply

It also states that a control system can auto reset

after a power cut so that the boilers can restart

automatically if self proving devices are in place

Boiler House Applications

– Gas Pressure Proving

IGEM UP/1A Edition 2

This document states, “where there has been a

complete loss of pressure for any reason

e.g. the closure of a valve, it can result in the

complete loss of pressure which necessitates

testing and purging before resumption of

supply”

IGEM UP/2 Edition 3

If automatic flame safe guards are not fitted on all

appliances, in the event of closure of a gas solenoid valve,

the AIV (Automatic Isolation Valve) shall not be allowed to

automatically reset until the downstream pipework is

checked.

BB100 also discusses that if the boilers don’t have

incorporated self proving, then a combined gas detection

and gas proving should be installed.

If a gas booster or compressor is installed, then IGEM UP/2

Edition 3 recommends “it is normal good practice to fit a low

pressure cut off switch or transducer to comply with such a

requirement”

Any boiler house should have means of shutting off the

fuel supply in the event of a fire. This includes

emergency knock-off buttons at the entrance to the

boiler room

In the event of a genuine alarm the panel will need to

be manually reset

In the event of a power failure, an auto restart system

is recommended when proving devices are in place.

Fire alarms and BMS systems can be interfaced

Normally a fusible link is installed over each boiler

In Summary

School Science Labs and Food

Technology

Gas Proving in Science Labs and Food

Technology

UP11 Edition 2, Gas Installations for

Educational Establishments

Laboratory Gas Control –

UP11 Edition 2

Section 6.2.3 states that “where it is not

practicable to install a manual quarter turn

valve in a readily accessible position, or

where it is required to interlock the gas

supply with other safety systems such as air

flow, fire or gas detection, an automatic

means of isolation shall be installed.”

Laboratory Gas Control –

UP11 Edition 2

The document states under 6.2.4.1 that, “Where

a gas solenoid valve is required the system shall

include a downstream integrity check before the

valve can be reopened”

“Downstream integrity check” means gas pressure

proving system

This means, if it is not possible to have a readily

accessible manual quarter turn you need a gas

solenoid valve, therefore gas proving should be

installed

Laboratory Gas Control –

BB100

BB100 states that:

“Each laboratory should be fitted with a lockable

isolating valve to enable gas supplies to gas taps

and benches to be shut off at the end of the day”

Gas Proving Systems for use in school lab

environments usually have key switch isolation

allowing the teacher to lock away the gas supply out

of hours

How does a gas proving

system work?

Turn the key into

the on position

How does a gas proving

system work?

Turn the key to the on

position

The system opens the gas

valve for 5 seconds allowing

gas to fill the downstream

pipe work

How does a gas proving

system work?

The valve then closes

The transducer then monitors

to see if the gas pressure

holds.

How does a gas proving

system work?

If the pressure holds the

valve will re-open and

allow gas to the classroom

How does a gas proving

system work?

If the pressure drops the

panel will indicate ‘Test Fail’.

The user will have to

close the open appliances

and reset the system.

Food Technology

Section 11.2.4. states that “mechanical

ventilation or extract systems shall be

interlocked”.

Section 11.2.4 also goes on to say:

“Note. Must be read in conjunction with 11.2. 5

and accompanying note.”

“Where the ventilation requirements for new

installations cannot be met, CO2

monitoring shall

be fitted. It shall provide an alarm condition at

not more than 2,800 ppm to warn the teaching

staff to increase ventilation and an automatic

shut down of the gas supply at 5,000 ppm.”

Section 11.2.5 is clear in stating that:

“Means shall be provided to monitor the correct

provision of air supplies, for example by airflow

monitoring by air flow switches or by fan power

monitoring. Failure shall lead to the shut down of

the gas supply to the cookers.”

BB101 – Ventilation for

School Buildings Section 1.4

Ventilation should be provided to limit the concentration

of carbon dioxide in all teaching and learning spaces.

When measured at seated head height, the average

concentration of carbon dioxide should not exceed 1500

parts per million (ppm).

This is based on the need to control carbon dioxide

resulting from the respiration of occupants. In teaching

and learning spaces, in the absence of any major

pollutants, carbon dioxide is taken to be the key indicator

of ventilation performance for the control of indoor air

quality.

Commercial Kitchen Timeline

BS 6173:2009

TB-140 (edition 1)

April 2012

TB-140 (edition 2)

June 2014

IGEM UP/19

November 2014

BS 6173:2001

HSE Sheet 26

Jan 2016

Commercial Kitchens

BS 6173:2009

Was originally brought in around 2001 in response

to health and safety in commercial kitchens

Chefs and kitchen staff were suffering from health

problems due to poorly ventilated kitchens

The by-products from natural gas and cooking

were causing illness such as throat cancer as well

as carbon monoxide exposure

BS6173:2009 states that gas should only be

available in a commercial kitchen provided

the ventilation is running at the required

level

Should the ventilation fail or be running at

an insufficient level, the gas supply to the

kitchen should be isolated

A Gas Interlock System will monitor the

ventilation and control an automatic gas

valve

What is BS6173:2009?

If a Kitchen is going through a major

refurbishment or is being fitted out as new

they have to comply

You can use Air PD switches or current

monitors

If any of the catering equipment does not

have FFD, a gas pressure test should be

carried out on the gas line at start up

There must be an emergency stop button at

each emergency exit from the kitchen

Further Points to

BS6173:2009

• If all the cooking equipment has flame failure

devices, a standard interlock system can be used

BS6173:2009

BS6173:2009

• If ANY OF the cooking equipment does not have

FFDs then an interlock/gas proving system is

required

BS6173:2009 Sections 12.2 refers Under the

heading “Safety precautions” States....

“Only detectors designed to operate in a commercial

catering environment shall be installed. They shall give

an audible alarm and be linked with an automatic gas

shut-off system”

It goes on to say

“Carbon Dioxide alarms are becoming available for

use in commercial installations. Their use should be

considered within the site specific risk assessment of

the appliances and the installation”

These alarms should only be regarded as a backup to

the required interlock systems.

CO2

Monitors

IGEM UP/19 was released in November 2014 and replaced

TB140 (edition 2) and confirms many aspects of BS6173:2009

IGEM UP/19 clarifies to the gas engineers different scenarios

of how a gas interlock should be installed

Recommends using a CO2

sensor on kitchens that pre-date

2001 or don’t have an interlock system. (5.2. note 2)

Where variable fan speed controllers are installed a CO2

sensor should be included as apart of the gas interlock

requirements (4.3.2)

Includes various flow charts and diagrams on the process

involved when making changes to a kitchen.

IGEM –UP/19

HSE Catering sheet 26 Solid Fuel

Appliances

This guidance is aimed at the catering and hospitality industry

the guidance covers the safe use of solid fuel appliances such

as tandoori ovens, charcoal grills and wood fired pizza ovens.

• You should fit an audible carbon monoxide alarm suitable

for commercial kitchens and have appropriate evacuation

procedures.

• The alarm should be interlocked with any mechanical

ventilation that is fitted.

• The extract fan should remain running until all solid fuel

has been extinguished or interlock a ventilation system with

a carbon monoxide alarm (e.g The Merlin 1750.)

www.snsnorthern.com

Simple Specification Solution

The gas ventilation/gas interlock system to comply with BS6173:2009 shall be manufactured and supplied by S&S Northern Ltd

(Tel: 01257 470983)

The model to be supplied is the Merlin 2000S System which is 178mm (height) x 254mm (length) x 62mm (depth) and this will come with a

gas pressure transducer to carry out a gas proving test on all the downstream appliances.

The Merlin CO2 Monitor shall be supplied in accordance with the IGEM/UP19. The Merlin CO2 Monitor has a screen to show the

concentration of CO2 in the kitchen area. It also has a low, medium and high level LED to suggest when the ventilation should be increased.

In the event where the CO2 rises above 4500ppm the gas solenoid valve should close and the panel go into CO2 High alarm.

The gas safety systems should be interlocked with the ventilation using 2 x Air Pressure Differential Switches.

1 x Merlin 2000S Panel (incl. Gas Pressure Transducer)

1 x Merlin CO2 Monitor for Kitchens

2 x Air PD Switch (20-300PA)

1 x Gas Solenoid Valve is also required

There should be a means of isolation by each main exit and any emergency knock-off buttons should be connected with the gas safety

system. Also connections can be made to the fire alarm and BMS to shut the gas solenoid valve in the event of a genuine alarm.

S&S Northern has launched a comprehensive BIM Object

library to support the industry’s transition to digital building

modelling. Objects are available in 2 file formats: Revit, IFC.

Adjusts ventilation based on cooking activity

Can be combined with traditional interlock

and gas proving

Tends to be used in larger establishments

Demand Controlled

Kitchen Ventilation (DCKV)

Reduces energy consumption by varying

ventilation to match cooking load

Minimises unnecessary heat loss by

extraction

Reduces ventilation noise levels at times of

low kitchen activity

Takes responsibility for sufficient ventilation

rates away from kitchen staff

Benefits of DCKV

CIBSE TM50

◦ “Demand-based, or variable air volume (VAV) ventilation, is almost certainly the single most

effective means of saving energy in a commercial

kitchen ventilation system.”

◦ “These systems can achieve savings of up to 60% in fan energy usage.”

◦ “For every kW/h of electricity and gas saved the corresponding reduction in carbon footprint is

0.43 kg and 0.19 kg respectively. It is not

uncommon for establishments to save several

thousand kW/h per year using this type of

equipment and to benefit from the direct and

indirect savings.”

Current Guidelines

DW/172

◦ “Kitchen ventilation systems with total exhaust airflow rates exceeding 2.5m

3/s should be

considered for DCKV systems”

◦ “The primary benefit of this type of system is that the electrical energy consumed by carefully

modulating extract and supply fans can be

considerably reduced, as opposed to that

consumed if both fans were running continuously

throughout the day. These savings will be further

enhanced by the reduced cost of heating / cooling

the make-up-air. Typical payback periods can be

between 1 and 5 years, depending on operating

hours.”

Current Guidelines

Automatically varies fan speeds using one

or more of the following:

◦ Real time gas consumption

◦ CO2

levels in the cooking area

◦ Steam or smoke detection in the canopy

◦ Excess heat detection in the canopy

The Merlin 3000S