Dear All.

We have the spare old control valves which we want to reuse for our new project. I want to know how to select the old control valve for new requirement.

e.g.New required conditions:

Max. Flow rate= 1500 Kg/Hr.
shut off press.== 4 kg/cm2
Delta P== 0.2 Kg/Cm2
Line Size== 25 mm
Liquid sp.gr== 0.895
Operating Temp.==40 °C
& I have a old control valve
Size==25 mm
Inlet Pressure== 4.5 Kg/cm2
outlet press.== 4.2 Kg/cm2
CV stamped on it is ==4

Can i utilize this valve for the new conditions. I want to do this for almost 20 control valves. I would like to know what are the parameters to consider for retrofitting of old control valves for new conditions. Thanks in advance!!!!!

 

Hi,

To use an existing valve for new application, the following points need to be noted,

- suitability of existing trim material for the new application. Like H2S presence, high temperature etc

- actuator design is suitable for the new shut off pressure and fail safe condition.

- calculate the new cv and see the existing valve cv is sufficiently above (not too high !!) the required one.

- flange size suitability.

Hope its clear.

bye.