torque sizing for ball valve

[MostafaNoorelahi]

we are new to oil company, our sales threw a question to me regarding .we are need torque valve. 1.) NPS 16, class 600, Trunnion ball valve, seat material Nylon, manufacture valve cameron type: T-31. what might be the approximate breakaway torque ? 2.) What will be the approximate torque for Actuator?

 

[JohnGP]

I'm not sure that I understand your situation completely - if you need a torque value for a Cameron valve, then speak to Cameron. If you are making a Cameron clone, then there are many variables that will affect the breakaway torque value. As to the required torque for the actuator, that depends on the margin, or safety factor specified, and it's quite often the client will require a certain value, such as 1.5 minimum in my present project.
You don't want to be breaking valve stems though, so there is some liaison required with the valve manufacturer.
Cheers,
John

 

[MostafaNoorelahi]

Thanks JohnGP
We asked Cameron but he did not respond. We need torque of valve. Could you please help me about it?
How can you help me with it?
Best regards

 

[JohnGP]

I'm sorry, we don't have any Cameron valves.

 

[gerhardl]

Any valve supplier should have this available, something is failing in communication here! Alternative: if you can find out which actuator the supplier would offer for your valve, this is listed with torque tables at the factorys homepage.

If you search this forum for 'torque' you will find comments of how much torque can vary, depending of a number of fluid and operation conditions.

 

[Kreot]

To make this correct You need to discuss with both the valve and actuator supplier. Normally this is standard in the documentation delivery from the supplier.
It will also be dependent on the seat design of the valve, floating seats require different break-away torque than fixed seats, but as mentioned above, many factors need to be taken into consideration.

 

[Dean8573]

All valves have torque figures are standard, where these can not be obtatined then the following can be done:

Carry out breakout tetsing to the valve, this would consist of pressuring valve and recording required torque to operate, run and close the valve and vice versa. As your valve is of considerable size it most likely that this would only work if you were to use a norbar 9,14 or equivilant.

From the torque figures you obtain you would multiply this value by your required Factor of safety (usually 1.5 for XV and 2 for ESDV, SDV and BDV's) when you have done this you know have the minimum torques you require your actuator to output to suitabbly fit the actuator to the valve.

if you still can not aasatain the valve torques then you can look to use previous manufacturers such as TK as they are known in th indusrty to have high torque values in comparrison to other manufacturers.

thanks
D