Using Swagelok Valve Sizing Technical Bulletin calculate air

Using Swagelok Valve Sizing Technical Bulletin: calculate air pressure drop across a valve with C_v=0.001 if the flow rate is 0.2 sefm. The inlet pressure is 1000 psig.

Solution

Enter the vertical scale with the inlet pressure at the valve (p1 = 1000 psig).

Read across to the desired flow rate (q = 0.2 std ft3/min).

The diagonal line is the desired Cv value (Cv = 0.0010).