Calculating Stresses in Valve Stem i.e. during operation is the Stem subjected to 50% or more SMYS

[Piper84]

Hi Everyone,

This will be my first post on the website, I have looked through previous threads and couldn't seem to find the answer.

Basically I am wanting to know the following:

With regards to valve Stems, if I am trying to work out if the stresses exceed say 60% of SMYS how do I go about working that out. For a pipe its simple as its related to Barlows formula.

I would be grateful if someone could point me in the right direction here with regards to valve stem. I can get the SMYS from the specific material specification but during operation how can I determine if the valve stem is being subjected to say 60%% or more than its SMYS? this would be for Manual and Actuated vales

Thanks in advance.

 

[SPDL310]

You would calculate the stresses your stem would see, and compare them to an allowable stress which is equal to your SMYS multiplied by your utilization factor of 60%. You would need to look at compressive and tensile loads, as well as buckling and bending deflection on all unguided portions. You should also consider maximum thread stresses as well.

 

[Piper84]

Thank You SPDL310