Hello fellow Stressers,

Is there a sif for valve and strainer?

Many Thanks,

I believe these elements are taken as rigid and stress evaluation is not done for these!

Shahid is correct, stress evaluation is not performed for components such as valves and strainers. However, I have seen some organizations apply an SIF of 2.0 on the pipe node connecting to such components. Check with your company (or client) standards on this.

You're right Richard...I've read it in one of the stress procedure in the company I'm working for and I was confused and can't find an explanation on this...

CAESAR II will not evaluate stress on rigid elements but that does not mean that the piping codes give these components a free pass.
See B31.3 paragraph 302.5 Mechanical Strength for an example.
Setting SIF=2 is one way to draw attention to this issue.

Thanks Dave... Actually I've just came along with it as I was reading the company practices regarding stress analysis...But when I'm checking some of their calcs I can't find any SIF's near valves...Anyway, I think this is one of the what we call "engineering judgment" where maybe the original author of that technical article has some experience with valves and strainer and putting SIF will cover some of the uncertainties in the design, say without SIF no support is required near the valve/strainer but introducing SIF a support might be required although the load is a Sustained load where SIF=0.75i but not greater than 1.

Sorry I mean SIF=0.75i but not less than 1...

It is strange,One of company has advised to use reduced section modulus in the piping flexibility design where reduced bore valves are used. What is the relationship here?