Valve Cv Formula Gas. As a gas or vapor compresses with changes in pressure, its density changes correspondingly. It applies to the factor of the head drop (δh) or pressure drop (δp) over a valve with the flow rate q.
They express coefficient cv/kv as the flow rate of water in g.p.m. Because the fluid is a gas and δp ≥ p1 / 2 so we will use the formula. Types of control valves noise
Equations displayed for easy reference.
Cv =200 √1.8/5 = 200 √.36 = (200)(0.6) = 120 from cv table: From cv table, the corresponding valve position is 70% open. [m3/h] for a pressure drop of 1 psi [1 bar] across a flow passage [flow coefficient: The use of this flow coefficient (c v) calculator leads to a standard calculation to compare valve capacities.