Dry Pipe System Volume Calculator

Calculate air volume, trip time, and water delivery time for dry pipe sprinkler systems per NFPA 13.

Input Parameters

Results

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Total Air Volume
cu ft
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Differential Ratio
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Est. Water Delivery Time
sec
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NFPA 13 Max Volume
gallons
Note: NFPA 13 Section 7.2.3.1 limits dry pipe systems to 750 gallons. Water delivery must occur within 60 seconds at the most remote sprinkler. Quick-opening devices (accelerators/exhausters) are required for systems over 500 gallons. Air pressure is typically set at 20 psi above trip pressure.

Reference

Air Volume = Pipe Volume × 0.1337 cu ft/gal Differential Ratio = Water Pressure / Air Pressure Delivery Time ≈ (Pipe Volume / Flow Rate) × 60 sec Flow Rate = N × K × sqrt(P_min) NFPA 13 Max dry system volume: 750 gallons