Choke Valve @ Wellhead Piping

Posted by: Borzki

Choke Valve @ Wellhead Piping - 08/24/22 06:32 PM

Hello fellow Stressers,

Normally choke valve have a very high pressure drop (e.g 5900psi to 780 psi).

In reality, is there a possibility that a thrust force with a very high magnitude will be developed in choke valve due to pressure difference?

How do you approach this in stress analysis? or it will normally be a case of AIV that may excite the pipe wall.

Warm Regards,
Posted by: Borzki

Re: Choke Valve @ Wellhead Piping - 08/27/22 03:50 AM

Upon searching, the unbalanced force can be controlled via fluid dynamics inside the valve. A CFD can be performed to optimize this unbalance dynamic force.

See below:

https://www.eng-tips.com/viewthread.cfm?qid=266369

Cheers!!
Posted by: Michael_Fletcher

Re: Choke Valve @ Wellhead Piping - 08/30/22 09:49 AM

You framed the question incorrectly. As we all have at some point or another. smile

It's not because there's pressure differential that's there's a force; the fluid accelerating through the orifice is the reason there's a force in "normal" operating conditions.

If a pressurized line dead-ends to an end cap, we don't place any amount of force acting on the end, despite internal pressure often being larger than the external pressure, simply because the pressure acts somewhere on the opposite upstream side.

But if we put a hole in that end cap, we now have a jet force we must account for.

But if we put another end cap to contain that jet force and we bleed it off somehow, that jet force transforms itself into a lower pressure that acts on some other opposite surface. Presto, your pipe doesn't fly off into the sunset.

But if the choke valve is opening and closing wildly because someone put the sensor on the wrong end of the downstream pipe, then you may have to consider the pressure imbalance if the choke valve can actually open wide and fast enough to let a significant pressure wave through.
Posted by: Borzki

Re: Choke Valve @ Wellhead Piping - 08/30/22 06:27 PM

Thanks Michael for elaborating more. Now it's clear.

I haven't look what's happening inside the valve in my first question.:)

Warm Regards,