hi,

suppose a steam line with a control valve on it.
valve is in manual.
when the valve is 100% open, let the flow be x kg/hr. now what is the flow when the valve is 50% open? conditions kept identical.

 

See below link for a discussion of valve characteristics and flow for water and steam valves: http://www.spiraxsarco.com/resource...n-actuation/control-valve-characteristics.asp


Bill

William (Bill) L. Mostia, Jr. PE Fellow
SIS-TECH Solutions, LP

Any information is provided on Caveat Emptor basis.

<b>moderator's note:</b> when you copy and paste the url above, make sure you delete the spaces.

 

It depends on the valve characteristic - for a typical large turbine, the curve of flow vs opening will be nearly but not quite linear. The flow relationship will also depend on the behaviour of the pressure source with flow - typically, the discharge pressure of the throttle valve will be almost directly proportional to the power developed by the turbine.