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Spring Operated Safety Valves in Liquid Systems

Calculate spring operated relief valves in liquid systems.

Relief safety valve

The minimum discharge area of a spring operated relief safety valve in a liquid system can be calculated as

A = q SG1/2 / (28.14 Kbp Kvisc dp1/2)                                    (1)


A = discharge area (Square Inches)

q = relieving capacity (Gallons per Minute)

SG = Specific Gravity of the fluid

Kbp = capacity correction for back pressure - 1.0 for atmospheric pressure systems

Kvisc = correction factor due to velocity - 1.0 for most water systems

dp = differential pressure - set pressure (psig) + over pressure (psig) - back pressure (psig)

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