Shut Off Pressure For Control Valve
Shut Off Pressure For Control Valve
(OP)
I want to know a brief description for shut off pressure of control valve which is located on pipeline in inlet of plant.
I found two description from other members,please let me know which of them is correct:
1-Line hydrotest pressure is 1.5 times design pressure. For cases like tube rupture we take credit of hydrotest pressure of low pressure side.
I would prefer to size control valve in such a case for 1.5 times design pressure so that I can close the valve in event of tube rupture.
2- In the oil and gas industry, the maximum shutoff pressure is taken as the maximum ANSI class pressure. So, on a 300# system, the shutoff pressure (actually, it is a differential since we also assume atmospheric on the other side) is 740 psi.
tanx
I found two description from other members,please let me know which of them is correct:
1-Line hydrotest pressure is 1.5 times design pressure. For cases like tube rupture we take credit of hydrotest pressure of low pressure side.
I would prefer to size control valve in such a case for 1.5 times design pressure so that I can close the valve in event of tube rupture.
2- In the oil and gas industry, the maximum shutoff pressure is taken as the maximum ANSI class pressure. So, on a 300# system, the shutoff pressure (actually, it is a differential since we also assume atmospheric on the other side) is 740 psi.
tanx





RE: Shut Off Pressure For Control Valve
This is what I think for the definition:
Shutoff pressure is the maximum pressure drop across the control valve under the worst case of high supply pressure and lowest downstream pressure. This data is given to size the actuator so that it can work the valve under any condition which may occure. Shutoff pressure has nothing directly to do with the pipe design pressure except that the pipe design pressure is set using similar process criteria (some margin above maximum process pressure).
best wishes,
sshep
RE: Shut Off Pressure For Control Valve
Stream condition in upstream and downstream of FCV is as follows:
upstream (P=74.6 bara . T= 63 oC and rating is 2500#)
downstream (P=71.5 bara . T= 54.2 oC and rating is 600#)
wellhead condition (P=185.8 bara . T= 86 oC)
let us know your suggestion for shutoff pressure.
Regards
irprocess
RE: Shut Off Pressure For Control Valve
best wishes,
sshep
RE: Shut Off Pressure For Control Valve
Some wellhead piping line lists lack a design pressure. If this is the case consider the full ASME or API line class pressure.