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Fire Protection Shop Drawing Review

Process

One of the final stages of the sprinkler system design process (prior to the pipefitter beginninginstallation) is the review and acceptance of sprinkler shop drawings (a.k.a. working plans, as

defined by NFPA 13: Standard for the Installation of Sprinkler Systems). Typical submissionsthat are required are sprinkler system piping plans, hydraulic calculations, and materials

submitted. (For this column, lets assume that the materials submitted meet the project

specifications.)

Sprinkler shop drawings should include the details of the project, such as the exact locations ofsprinklers and the equipment necessary for the operation of the system. It is important to provide

a clear representation of the hazards and commodities to be protected, the system piping design

concept, available water supply information, sprinkler system hydraulic demands, and building

construction information important to system layout and detailing (i.e., fire separations). Theseplans also should reflect coordination with other trades.

Several parties usually conduct a review of the sprinkler shop drawings, including the owners

representatives (architect, engineer, and insurer) and the local authority having jurisdiction, suchas the fire marshal or building subcode official. Working plans should be submitted for approval

prior to any equipment installation.

SPRINKLER WORKING PLANS

NFPA 13 provides thorough checklists of the information required to be shown on sprinkler

working plans, water supply data, and hydraulic calculation forms. Not all of the items listedbelow may be applicable on every project and are subject to the reviewers discretion.

According to NFPA 13 Section 22.1.3, working plans shall be drawn to an indicated cale, on

sheets of uniform size, with a plan of each floor. They also shall show those items from the

following list that pertain to the design of the system:

Name of owner and occupant

Location, including street address

Point of compass

Full height cross-section, or schematic diagram, including structural member information

if required for clarity, ceiling construction, and method of protection for nonmetallicpiping

Locations of partitions and firewalls

Occupancy class of each area or room

Locations and sizes of concealed spaces, closets, attics, and bathrooms

Any small enclosures in which no sprinklers are to be installed


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Size of city main in street and whether dead end or circulating if dead end, show the

direction and distance to the nearest circulating maincity main test results, and system

elevation relative to test hydrant

Other sources of water supply, with pressure or elevation

Make, type, model, and nominal K-factor of sprinklers, including sprinkler identification

number Temperature rating and location of high-temperature sprinklers

Total area protected by each system on each floor

Number of sprinklers on each riser per floor

Total number of sprinklers on each dry pipe system, preaction system, combined dry

pipe/preaction system, or deluge system

Approximate capacity in gallons of each dry pipe system

Pipe type and schedule of wall thickness Nominal pipe size and cutting lengths of pipe (or center-tocenter dimensions)where

typical branch lines prevail, size only one typical line

Locations and sizes of riser nipples

Type of fittings and joints and locations of all welds and bends Any sections to be shop-welded and the type of fittings or formations to be used (the

contractors responsibility to specify on the drawing)

Types and locations of hangers, sleeves, braces, and methods of securing sprinklers when

applicable

All control valves, check valves, drain pipes, and test connections

Make, type, model, and size of alarm or dry pipe valve and of preaction or deluge valve

Kind and location of alarm bells

Size and location of standpipe risers, hose outlets, hand hose, monitor nozzles, and

related equipment

Private fire service main size, length, location, weight, material, and point of connectionto city main; the sizes, types, and locations of valves, valve indicators, regulators, meters,

and valve pits; and the depth that the top of the pipe is laid below grade

Piping provisions for flushing

Where the equipment is to be installed as an addition to an existing system, with enough

of the existing system indicated on the plans to make all conditions clear

For hydraulically designed systems, the information on the hydraulic data nameplate

A graphic representation of the scale used on all plans

Name and address of contractor

Hydraulic reference points shown on the plan that correspond with comparable referencepoints on the hydraulic calculation sheets

The minimum rate of water application (density, flow, or discharge pressure), the design

area of water application, in-rack sprinkler demand, and the water required for hose

streams both inside and outside The total quantity of water and the pressure required noted at a common reference point

for each system

Relative elevations of sprinklers, junction points, and supply or reference points

If room design method is used, all unprotected wall openings throughout the floor

protected


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Calculation of loads for sizing and details of sway bracing

The setting for pressure-reducing valves

Information about backflow preventers (manufacturer, size, and type)

Information about antifreeze solution used (type and amount)

Sizes and locations of hydrants, showing size and number of outlets and if outlets are to

be equipped with independent gate valves Whether hose houses and equipment are to be provided and by whom

Static and residual hydrants that were used in flow tests

Size, location, and piping arrangement of fire department connection

Ceiling and roof heights and slopes not shown in the full height cross-section

Edition year of NFPA 13 to which the sprinkler system is designed

WATER SUPPLY

In addition to the sprinkler system working plans, review of the available water supply is

necessary. Most municipalities require a flow test to be performed within 12 months of systeminstallation. The flow data can come from a hydrant flow test or from an existing fire pumpsystem test (if applicable).

NFPA 13 Section 22.2.1 provides a checklist of required information as part of the

design/documentation process. Such information includes:

Location and elevation of static and residual test gauge with relation to the riser reference

point

Flow location

Static pressure, in pounds per square inch (psi)

Residual pressure, in psi Flow, in gallons per minute (gpm)

Date

Time

Who conducted the test or supplied the information

Other sources of water supply, with pressure or elevation

Table 1 Example detailed worksheet snapshot

ReferenceNozzle typeand location

Flow ingpm

Pipe size(inches)

Fittings anddevices

Pipe equiv.length

Friction loss(psi/ft) Req. psi

12 to 14qQ

0.00572.58

4.026120

E,DPV, GVlgthftg

tot

22.00034.000

56.000

0.092

Pt

PfP

e

13.51

5.17

11.2

7

14 to 13 q

Q

0.00

572.58

6.065 120 E, CV, E lgth

ftg

20.000

60.000

0.013 Pt

Pf

13.5

1


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tot 80.000P

e

5.17

11.2

7

13 to 15 qQ 0.00572.58 6.065120 GV, T

lgth

ftgtot

54.000

33.00087.000

0.013

Pt

PfPe

24.0

11.090.00

15 to 16qQ

0.00572.58

7.981120

lgth

ftgtot

200.000

0.000200.000

0.003

Pt

PfP

e

25.1

00.66

0.00

Qt 822.58 Pt25.7

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HYDRAULIC CALCULATIONS

Once the sprinkler system layout and the available water supply have been reviewed for

compliance with NFPA 13, you need to review the associated hydraulic calculations to verify

that the system doesnt exceed available water pressure or flow. Typically, hydraulic calculations

are developed using sprinkler system hydraulic calculation programs such as HASS orHydraCALC. Hydraulic calculations shall be prepared on form sheets that include a summary

sheet, detailed worksheets, and a graph sheet.

Summary Sheet

According to NFPA 13 Section 22.3.2, the summary sheet shall contain the followinginformation, where applicable:

Date

Location

Name of owner and occupant

Building number or other identification

Description of hazard, including the commodity classification, storage height, and rackconfiguration for storage applications

Name and address of contractor or designer

Name of approving agency

System design requirements, as follows:o Design area of water application, in square feet

o Minimum rate of water application (density), in gpm per square foot (Where

sprinklers are listed with minimum water application in gpm or pressure in psi,

the minimum rate of water application shall be indicated in gpm or psi.)

o Area per sprinkler, in square feet


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Figure 1 Example hydraulic graph

Graph Sheet

A graphic representation (see Figure 1) of the complete hydraulic calculation shall include the

following:

Water supply curve (provided from water supply data)

Sprinkler system demand (provided from detailed worksheet)

Hose allowance (where applicable)

In-rack sprinkler demand (where applicable)

REFERENCES

NFPA 13Automatic Sprinkler Systems Handbook, Chapter 22: Working Plans. National Fire

Protection Association, 2009.

STEVE ZIGA, CPD, CET, CFPS, is a principal with hpeGROUP, LLC inBerwyn, Pennsylvania. He is an officer on the ASPE Philadelphia Chapter

board of directors. Contact him at sziga @ hpegroup.com. For more

information or to comment on this article, e-mail articles @ psdmagazine.org.

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