3 replies to this topic

[Prachi]

What happens if I use a control valve one size higher than the line size? I know we always use a line size control valve or one size less than the pipe line. Since I have a situation where vendor can not give 1/2" valve but offered 1" valve, where as the line size is 1/2". Checked line sizing and 1/2" line is perfectly O.K.

Can anybody clarify? 

 

[breizh]

http://www.eptq.com/...b1-90db5b9bd7dd

 

Hi Prachi ,

Probably good to read .

Did you check with reputable vendors ?

Good luck.

Breizh

[fallah]

Prachi,

 

There is no rule, other than choosing the control valve by Cv, not line size. The valve body size could be higher than the line size, but the valve trim should be reduced such that the operational opening/closing range can provide the required minimum and maximum Cv as per process requirements...

[farid.k]

 

What happens if I use a control valve one size higher than the line size? I know we always use a line size control valve or one size less than the pipe line. Since I have a situation where vendor can not give 1/2" valve but offered 1" valve, where as the line size is 1/2". Checked line sizing and 1/2" line is perfectly O.K.

Can anybody clarify? 

 

 

No problem. I do recommend to check the line sizing. Basically, if the line size is correct (within the suggested velocity limit), the control valve should be smaller or equal to pipe size. Quite rare to see the control valve bigger than line size. 2ndly, try some other vendor. I have an experience that some vendor cannot provide control valve ¼” but flowserve can provide it. Other thing is, the smaller, the cheaper. That’s why always go for the smaller control valve.