Operating a H2 type Choke Valve (API 6A)

[Ahsan96]

Hi Members,

I had designed a typical Choke Valve (H2 type), stem, and needle type, but facing a very unusual problem while testing. As per API 6A, we need to do validation testing by checking the valve during the operating cycle.

See below process

However, when we apply rated working pressure (in our case 10,000psi). We can not operate under pressure. The torque required to operate exceeds our calculated value and is impossible to operate by hand.

I am missing something very obvious, let me know with your feedback.

Regards,
AAI

 

[LittleInch]

This to me indicates there is a problem with your design, which you haven't shared with us.

Or your calculations are incorrect.

Who knows - we don't....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[jbeckhou]

Hello

A needle choke shouldn't be used to shut off the well. Can you share a cut view of the assy?

Petrotrim Services, LLC

http://www.petrotrim.com

 

[Ahsan96]

Hi Little,

True, feels like it, there might be an issue with the design. But the design is pretty straightforward H2-type choke see below for a typical design.

Hi jbeck,

NOT trying to shut off the valve, just we need to operate the stem using the handwheel, from the open to close position for a required number of cycles based on the PR level, and measure the required torque while the valve is under rated working pressure. If I understand it correctly API is asking you to do it under F.2.4.4 (as I shared above)

Regards,
AAI.

 

[LittleInch]

That's a typical design.

What is YOUR design?

Especially the needle / seat design.

I'm a bit surprised the flow is in that direction as this could force the needle into the seat of you get it a little bit wrong.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Ahsan96]

Hi All,

For those invested in this, we were able to get a torque value which was around 150 lb. ft (near to what I was able to calculate). Which was not that much, however, we had to update the design to a bigger handwheel after that we were able to operate it somewhat easily.

Regards,
AAI