Fire Protection Shop Drawing Review Process

One of the final stages of the sprinkler system design process (prior to the pipefitter beginning installation) 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 submissions that 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 of sprinklers 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). These plans 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, such as 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 listed below 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 nonmetallic piping 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

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 connection to 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 reference points 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

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 system installation. The flow data can come from a hydrant flow test or from an existing fire pump system 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

Nozzle type Flow in Reference and location gpm q Q q Q 0.00 572.58

Pipe size Fittings and Pipe equiv. Friction loss (inches) devices length (psi/ft) Req. psi 4.026 120 lgth 22.000 E,DPV, GV ftg 34.000 tot 56.000 E, CV, E lgth 20.000 ftg 60.000 13.5 Pt 1 Pf 5.17 P 11.2 e 7 Pt 13.5 Pf 1

12 to 14

0.092

14 to 13

0.00 6.065 120 572.58

0.013

tot

80.000

5.17 P 11.2 e 7 0.013 Pt 24.0 Pf 1 P 1.09 e 0.00 Pt 25.1 Pf 0 P 0.66 e 0.00 Pt 25.7 6

13 to 15

q Q

0.00 572.58

6.065 120

GV, T

lgth 54.000 ftg 33.000 tot 87.000 lgth 200.000 ftg 0.000 tot 200.000

15 to 16

q Q Qt

0.00 572.58 822.58

7.981 120

0.003

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 or HydraCALC. 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 following information, where applicable:

Date Location Name of owner and occupant Building number or other identification Description of hazard, including the commodity classification, storage height, and rack configuration 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

Total water requirements as calculated, including allowance for inside hose, outside hydrants, water curtain, and exposure sprinklers Allowance for in-rack sprinklers, in gpm Limitations (dimension, flow, and pressure) on extended coverage or other listed special sprinklers

Detailed Worksheets
The detailed worksheets or computer printout sheets (see Table 1) shall contain the following information:

Sheet number Sprinkler description and discharge constant (K) Hydraulic reference points (nodes on working plans) Flow in gpm Pipe sizes Pipe lengths, center-to-center of fittings Equivalent pipe lengths for fittings and devices Friction loss in psi per foot of pipe Total friction loss between reference points In-rack sprinkler demand balanced to ceiling demand Elevation head in psi between reference points Required pressure in psi at each reference point Velocity pressure and normal pressure if included in calculations Notes to indicate starting points or reference to other sheets to clarify data shown Diagram to accompany gridded system calculations to indicate flow quantities and directions for lines with sprinklers operating in the remote area Combined K-factor calculations for sprinklers on drops, armovers, or sprigs where calculations do not begin at the sprinkler

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 13 Automatic Sprinkler Systems Handbook, Chapter 22: Working Plans. National Fire Protection Association, 2009. STEVE ZIGA, CPD, CET, CFPS, is a principal with hpeGROUP, LLC in Berwyn, 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. prev Return to Index