Valve seat pressure. 1

[pramod1]

We want to hydrotest some loop where there are some valves in the system, we have already tested the valves in the manufacturer's shop. The valves are at present installed in position. Now we want to hydrotest the loop but we don't want to test these valves.
If we close these valves and undertake the test, how we can calculate the seat pressure of the valve which it can sustain?
Please reply back asap.

Thanks.
Pramod

 

[PAN]

For carbon steel or alloy steel valves, you can calculate the closure test as shown in ASME/ANSI B16.34.

Pressure Rating @ 100 F x 1.1

For an example, Carbon steel valve (Body A216-WCB) Class 300

The pressure for closure test is 740 x 1.1 = 814 psi.

 

[DTC]

The shut-in pressure of a control valve is determined
by a few different factors.

Normally the trim size, actuator size and bench setting
of the valve will determine the shut-in pressure.

Example:
Fisher 2" 600# ANSI RFF Type 667-D-45
* 1" Orifice Size
* Size 45 Actuator
* 14-30 psi Bench Set
* Fail Closed, Air To Open

** MAXIMUM SHUT-IN PRESSURE 3,006 PSIG - 3/4" PORT
** MAXIMUM SHUT-IN PRESSURE 1,649 PSIG - 1" PORT

Consult the supplier of the valve.
They will be able to provide you with the shut in pressure
that the particular valve is sized.

The shut in pressure will vary with various combinations of
trim, actuator sizes and bench settings.