PSV Outlet Vent Stack - SR or LR

[DGrayPPD]

What is more common to use on a PSV vent outlet to atm; LR elbow or SR elbow?

Reading a section in "Piping Handbook - 7th Edition" that states.. "The relief valve outlet shall consist of the mating flange and a fitting-bound short-radius elbow, in order to minimize the moment and forces imposed on the valve body."

Just curious if this is a common practice that I should start incorporating into my designs.

Thanks
DGrayPPD

 

[BigInch]

Probably not a bad idea, as moments and bending stresses can be aggrevated by longer radaii, however better yet would be to calculate the loads and stresses and provide additional support for the blow down vent whenever it is needed. Do not underestimate the loads that a blow down of this kind can have and alsways get a structural engineer to design the supports and braces. That's not something to leave up to a piping engineer.

Reaction to change doesn't stop it