The document summarizes the hydraulic calculations for a wet pipe fire sprinkler system for a 1,500 square foot commercial building. It details the calculations to determine the required water pressure and number of sprinklers needed based on the building size, pipe diameters, and water flow and density requirements. It finds that 12 sprinklers are needed with a minimum required pressure of 11.96 PSI to ensure proper water coverage based on NFPA standards.
The document summarizes the hydraulic calculations for a wet pipe fire sprinkler system for a 1,500 square foot commercial building. It details the calculations to determine the required water pressure and number of sprinklers needed based on the building size, pipe diameters, and water flow and density requirements. It finds that 12 sprinklers are needed with a minimum required pressure of 11.96 PSI to ensure proper water coverage based on NFPA standards.
The document summarizes the hydraulic calculations for a wet pipe fire sprinkler system for a 1,500 square foot commercial building. It details the calculations to determine the required water pressure and number of sprinklers needed based on the building size, pipe diameters, and water flow and density requirements. It finds that 12 sprinklers are needed with a minimum required pressure of 11.96 PSI to ensure proper water coverage based on NFPA standards.
The document summarizes the hydraulic calculations for a wet pipe fire sprinkler system for a 1,500 square foot commercial building. It details the calculations to determine the required water pressure and number of sprinklers needed based on the building size, pipe diameters, and water flow and density requirements. It finds that 12 sprinklers are needed with a minimum required pressure of 11.96 PSI to ensure proper water coverage based on NFPA standards.
The presentation deals with hydraulic calculations of the wet pipe fire sprinkler system of a commercial building under Ordinary Hazard Group 1 (OH1) occupancy. The Sample Design Layout (above) has a floor area of 30 m by 50 m (1,500 m2), one- story commercial building which served by a 4-inch riser and believed to be within 52,000 ft2 (4,831 m2) maximum fire sprinkler system protection coverage per riser. The design area of protection is 1,500 ft2 (139.4 m2) with a water density of 0.15 gpm/ft2. Each sprinkler covers 129.17 ft2 (12 m2). Using area/density method to compute for the Design Area (Area of Protection). 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑆𝑝𝑟𝑖𝑛𝑘𝑙𝑒𝑟𝑠 𝑡𝑜 𝐶𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑒 𝑆𝑝𝑟𝑖𝑛𝑘𝑙𝑒𝑟 𝐶𝑜𝑣𝑒𝑟𝑎𝑔𝑒 = 4 𝑚 × 3 𝑚 = 12 𝑚2 = 129.17 𝑓𝑡 2 𝐷𝑒𝑠𝑖𝑔𝑛 𝐴𝑟𝑒𝑎 1,500 𝑓𝑡 2 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑆𝑝𝑟𝑖𝑛𝑘𝑙𝑒𝑟𝑠 = = 𝑆𝑝𝑟𝑖𝑛𝑘𝑙𝑒𝑟 𝐶𝑜𝑣𝑒𝑟𝑎𝑔𝑒 129.17 𝑓𝑡 2 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑆𝑝𝑟𝑖𝑛𝑘𝑙𝑒𝑟𝑠 = 11.61 ≈ 12 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑆𝑝𝑟𝑖𝑛𝑘𝑙𝑒𝑟𝑠 𝑎𝑙𝑜𝑛𝑔 𝐵𝑟𝑎𝑛𝑐ℎ 𝐿𝑖𝑛𝑒 𝑆 = 4 𝑚 = 13.12 𝑓𝑡 𝑎𝑝𝑎𝑟𝑡 PASCUA, PAUL DANIELLE S. 12/14/2022 20121182632
1.2√𝐷𝑒𝑠𝑖𝑔𝑛 𝐴𝑟𝑒𝑎 1.2√1,500 𝑓𝑡 2
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑆𝑝𝑟𝑖𝑛𝑘𝑙𝑒𝑟𝑠 𝑎𝑙𝑜𝑛𝑔 𝐵𝑟𝑎𝑛𝑐ℎ 𝐿𝑖𝑛𝑒 = = 𝑆 13.12 𝑓𝑡 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑆𝑝𝑟𝑖𝑛𝑘𝑙𝑒𝑟𝑠 𝑎𝑙𝑜𝑛𝑔 𝐵𝑟𝑎𝑛𝑐ℎ 𝐿𝑖𝑛𝑒 = 3.54 ≈ 4 𝑆𝑝𝑟𝑖𝑛𝑘𝑙𝑒𝑟𝑠 𝑎𝑙𝑜𝑛𝑔 𝐵𝑟𝑎𝑛𝑐ℎ 𝐿𝑖𝑛𝑒 Starting at the physically most remote sprinkler head. Each sprinkler has a protection area of coverage. This means that the sprinkler head has a specific protection coverage floor area. Our Sample covers 129.17 ft2 (12 m2) per sprinkler head. First step is to calculate the flow from the most remote (remotest) sprinkler head. Thus, from: 𝑄 =𝐷×𝐴 𝑊ℎ𝑒𝑟𝑒: 𝑄 = 𝑆𝑝𝑟𝑖𝑛𝑘𝑙𝑒𝑟 𝐹𝑙𝑜𝑤, 𝐺𝑃𝑀 𝐺𝑃𝑀 𝐷𝑒𝑛𝑠𝑖𝑡𝑦 𝐷 = 𝐷𝑒𝑛𝑠𝑖𝑡𝑦, 2 ( ) 𝑓𝑡 𝐴𝑟𝑒𝑎 𝐶𝑢𝑟𝑣𝑒 𝐴 = 𝑃𝑟𝑜𝑡𝑒𝑐𝑡𝑖𝑜𝑛 𝐴𝑟𝑒𝑎 𝑜𝑓 𝐶𝑜𝑣𝑒𝑟𝑎𝑔𝑒 𝑝𝑒𝑟 𝑆𝑝𝑟𝑖𝑛𝑘𝑙𝑒𝑟, 𝑓𝑡 2 𝑇ℎ𝑒𝑛, 𝐺𝑃𝑀 𝑄 = 0.15 (129.17 𝑓𝑡 2 ) 𝑓𝑡 2 𝑄 = 19.37 𝐺𝑃𝑀 𝐹𝑟𝑜𝑚,
𝑃 = 11.96 𝑃𝑆𝐼 > 7 𝑃𝑆𝐼 Note: NFPA sets a minimum pressure of 7 PSI at the end sprinkler in any event, so that a proper spray umbrella is ensured. Calculate the Friction Loss through pipe using Hazen-William’s formula: 4.52𝑄1.85 𝐹𝐿 = 1.85 4.87 𝐶 𝑑𝑖 𝑃𝑆𝐼 𝑊ℎ𝑒𝑟𝑒: 𝐹𝐿 = 𝐹𝑟𝑖𝑐𝑡𝑖𝑜𝑛 𝐿𝑜𝑠𝑠, ( ) 𝑓𝑡 PASCUA, PAUL DANIELLE S. 12/14/2022 20121182632 𝑄 = 𝐹𝑙𝑜𝑤, 𝐺𝑃𝑀 𝐶 = 𝑅𝑜𝑢𝑔ℎ𝑛𝑒𝑠𝑠 𝐶𝑜𝑒𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑡, (𝐵𝑎𝑠𝑒𝑑 𝑜𝑛 𝑃𝑖𝑝𝑒 𝑀𝑎𝑡𝑒𝑟𝑖𝑎𝑙) 𝑑𝑖 = 𝐼𝑛𝑡𝑒𝑟𝑖𝑜𝑟 / 𝐼𝑛𝑠𝑖𝑑𝑒 𝑃𝑖𝑝𝑒 𝐷𝑖𝑎𝑚𝑡𝑒𝑟, (𝐼𝑛𝑐ℎ𝑒𝑠) Sprinkler No.1 (S-1) is supplied by a 4 m (13.12 ft) by 1-inch diameter (1.045 in. actual inside diameter) B.I. Piper Schedule 40. 4.52(19.37 𝐺𝑃𝑀)1.85 𝐹𝐿 = 𝐶 1.85 𝑑𝑖4.87 NFPA 13, section 22.4.4.7 (3) states that “calculate the loss for a tee or a cross where flow direction change occurs based on the equivalent pipe length of the piping segment in which the fitting is included.” Therefore, friction loss in PSI, given the Total length of pipe = Length of pipe + Equivalent pipe length of fittings.
𝐹𝑟𝑖𝑐𝑡𝑖𝑜𝑛 𝐿𝑜𝑠𝑠 = 𝐹𝐿 𝑥 𝑇𝑜𝑡𝑎𝑙 𝑙𝑒𝑛𝑔𝑡ℎ 𝑜𝑓 𝑝𝑖𝑝𝑒
𝐹𝑟𝑖𝑐𝑡𝑖𝑜𝑛 𝐿𝑜𝑠𝑠 = 0.1226 𝑃𝑆𝐼/𝑓𝑡 (13.1 + 0) 𝑓𝑡 𝐹𝑟𝑖𝑐𝑡𝑖𝑜𝑛 𝐿𝑜𝑠𝑠 = 1.61 𝑃𝑆𝐼 NFPA-13, section 22.4.4.7 (4) states that “The tee at the top of a riser nipple shall be included in the branch line, the tee at the base of a riser nipple shall be included in the riser nipple, and the tee or cross at a cross main-feed main junction shall be included in the cross main.” This tells us where to include the fitting, into upstream piece of pipe. This is why the Tee fitting at the cross main at point A on our drawing is added to the branch line friction loss calculation and not the friction loss through the piece of 4-inch main. If you are wondering about all of those Tee fittings that the sprinklers are threaded into, NFPA-13, section 22.4.4.7 (9) states “Friction loss shall be excluded for the fitting directly connected to a sprinkler.” Therefore, we ignore the Tee fittings for the sprinklers. 𝐸𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒, 𝑃𝑒 = 0.433 𝑥 𝐸𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 (𝑓𝑡) From the Top of the Riser (TOR) to the Bottom of the Riser (BOR), the total length of 4-inch diameter B.I.Pipe Schedule 40 is 4m (13.1 ft) with 1-Std. Elbow, 1-Alarms Check Valve, 1-os&y Gate Valve (Isolation Valve), and 1-Swing Check Valve. Hose Allowance Assumption: Inside Hose Allowance = 100 GPM, Outside Hose Allowance = 0 (Fire Hydrant) PASCUA, PAUL DANIELLE S. 12/14/2022 20121182632
Hydraulic Calculation for AUTOMATIC FIRE SPRINKLER SYSTEM of ONE-STOREY COMMERCIAL BUILDING Nozzle Fittings Pipe Friction Required Step Flow Pipe Size C k Ident. & & Equivalent Loss Pressure No. (GPM) (Schedule 40) Factor Factor Location Devices Length (ft) (psi/ft) (psi) q Nominal 1" Length 13.12 Pt 11.96 1 1 BL-1 None Fittings 0 120 0.1226 Pe 0 5.6 Q 19.37 Act. 1.049 Total 13.12 Pf 1.61 1 q 20.63 Nominal Length 13.12 Pt 13.57 1/4" 2 2 BL-1 None 120 0.1233 5.6 Fittings 0 Pe 0 Q 39.99 Act. 1.38 Total 13.12 Pf 1.62 1 q 21.82 Nominal Length 13.12 Pt 15.18 1/4" 3 3 BL-1 None 120 0.2760 5.6 Fittings 0 Pe 0 Q 61.81 Act. 1.38 Total 13.12 Pf 3.62 1 q 24.28 Nominal Length 6.56 Pt 18.81 BL-1 1/2" 4 4 Tee 120 0.2405 5.6 to RN Fittings 8 Pe 0 Q 86.10 Act. 1.61 Total 14.56 Pf 3.50 q Nominal 2" Length 1 Pt 22.31 5 RN Tee Fittings 10 120 0.0712 Pe 0.43 5.6 Q 86.10 Act. 2.067 Total 11 Pf 0.78 2 BL-1 q Nominal Length 9.84 Pt 23.52 1/2" 6 to BL- None 120 0.0300 16.67 Fittings 0 Pe 0 2 Q 86.10 Act. 2.469 Total 9.84 Pf 0.29 2 BL-2 q 86.64 Nominal Length 9.84 Pt 23.82 1/2" 7 to BL- None 120 0.1087 16.67 Fittings 0 Pe 0 3 Q 172.73 Act. 2.469 Total 9.84 Pf 1.07 2 BL-3 q 83.17 Nominal Length 139.4 Pt 24.89 1/2" 1-Std. 8 to 120 0.2249 16.67 Elbow Fittings 6 Pe 0 TOR Q 255.90 Act. 2.469 Total 145.4 Pf 32.70 q Nominal 3" 1-Std. Length 13.12 Pt 57.59 TOR Elbow, Fittings 40 Pe 5.68 9 to 120 0.0781 16.67 Q 255.90 Act. 3.068 1-GV, BOR Total 53.12 Pf 4.15 2-CV q Nominal 3" 5-Std. Length 59.04 Pt 67.42 BOR Elbow, Fittings 52 Pe 1.42 10 to 120 0.0781 16.67 Q 255.90 Act. 3.068 1-GV, PUMP Total 111 Pf 8.67 1-CV q 250 Nominal n/a Length n/a Pt 77.51 11 HOSE n/a Fittings n/a 120 n/a Pe n/a n/a Q 505.90 Act. n/a Total n/a Pf n/a
