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Sprinkler Hydraulic Calculation Simulator

NFPA 13 most-remote-area hydraulic calculation. Step through flow at each sprinkler head (Q = K√P), accumulate pressure loss along the branch line via Hazen-Williams, and plot the system demand point against the water supply.

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System PASSES — Adequate supply pressure

Demand: 264 GPM @ 0.2 psi (sprinklers 14 + hose 250 GPM) · Supply: 65 psi · Margin: 64.8 psi

Hazard Occupancy

Density: 0.15 gpm/ft² · Area: 1500 ft² · Hose: 250 GPM

Sprinkler K-Factor

System Pressure (available)65 psi

Sprinkler Spacing12 ft

Coverage area: 144 sq ft/head

Sprinklers in Design Area6

Pipe Material

Branch Line ID

Cross Main ID

Min Sprinkler Pressure

Q_min = 0.15 × 12² = 21.6 gpm

P_min = (Q/K)² = 0.1 psi

Step-by-Step Hydraulic Calculation — Most Remote Area

Head #	Pressure (psi)	Flow (gpm)	Cumul. Flow	Pipe	Pipe Loss (psi)	Pressure After Pipe
#1	0.10	1.8	1.8	1.049"	0.008	0.11
#2	0.11	1.9	3.7	1.049"	0.029	0.14
#3	0.14	2.1	5.8	1.049"	0.067	0.21
#4	0.21	2.6	8.3	2.067"	0.005	0.21
#5	0.21	2.6	10.9	2.067"	0.008	0.22
#6	0.22	2.6	13.5	2.067"	0.012	0.23
+ Hose stream allowance			+250	Total: 264 GPM @ 0.2 psi

NFPA 13 Method: Q = K√P at each head. Pipe loss per Hazen-Williams. Calculation starts at most-remote (lowest pressure) sprinkler and works back toward the riser. System demand point must fall below the water supply curve with a minimum 5 psi margin. Hose stream allowance per NFPA 13 Table 11.2.3.1.2.