API 6A Choke valve break torque & running torque

[jaydeep29]

Any body who had work in this type control valves design concern.
I want to know how to calculate break torque & running torque with formula.
Is is Open Thrust (lbs) = (Stem cross section are in inch)X(Line pressure)x(Packing load) + (Seat area)x(Valve factor)x(pressure drop difference)
Please verify my general equation for choke valve(control valve).

Thank you in advance.

My Mott: Stay calm and never give up.

 

[ricklts]

Jaydeep29,
What's the manufacturer say? New or used packing assembly? Service temperature? Lot's of questions.

Rick

 

[SPDL310]

The valve manufacturer should have a published torque chart from their validation testing included in the IOM. If that has not been provided What type of choke valve is it a needle valve, a cage and sleeve valve, is it pressure balanced? No mater the case the break open torque should be the highest torque value seen by your actuator running torques should be much less.

 

[jaydeep29]

Thank you for reply.
But my question is about equation for calculation break and running torque.I want to design.
Can any body can help me?


My Motto: Keep calm and never give up.

 

[LittleInch]

I don't believe there is any such thing as there are simply too many options and permutations. Also it depends on the make up and direction of flow, pressure, type of valve, trim, operation etc.

Until it was based on actual tests no one would believe it anyway.

Why not draw out what you're trying to do and why you wan to design this rather than just getting the data from a vendor?


My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way