Description

A quick-reference cheat sheet of core fire sprinkler hydraulic formulas, including K-factor, design density, velocity and Hazen-Williams equations.

A two-page quick-reference sheet covering the core hydraulic formulas used in fire sprinkler design, each with a worked example and its answer.

• K-factor equation: finding flow, pressure, or K-factor for a sprinkler head
• Design density: relating flow, density and coverage area
• Velocity in a pipe
• Pressure due to elevation (static head)
• The full-form Hazen-Williams equation, plus the short-form version using Kp constants
• C-factor values for common pipe materials (mild steel, cast iron, copper, stainless steel), and Kp values for steel and CPVC pipe across DN20–DN65, per EN 12845 / BS 9251
• A full symbols glossary in metric units

For the underlying theory behind these formulas, see the K-factor formula explained, velocity in a pipe, and the Hazen-Williams equation. Try the free online hydraulic calculators to run these formulas without doing the maths by hand.