B31.1 allowable miter in steam pipe
B31.1 allowable miter in steam pipe
(OP)
When building steam piping in accordance with the B31.1 Power Piping Code I would like to know what the allowable miter, if any, could be in the middle of an aprox. 30 ft. run of 12" Sch 40 CS pipe. We have an elevation change that requires a 5 degree offset. The run of pipe would have a 5 degree angle then an aprox. 10 ft. length of pipe, another 5 degree angle then the piping continues on to make the elevation change. Will a single bevel, open root, full penetration welded mitered joint, with a 2.5 degree angle on each pipe be an acceptable and an allowable solution. Or would a 5 degree bend be more acceptable than a miter? If so , why? The opp. pressure is 75 psi. max. The system will have a lower opp. pressure of 35 psi. during the off season. I see there are formulas for design in the code book but I'm not sure how to complete these design calcs. or if they're even necessary. Please advise. Thanks billbon





RE: B31.1 allowable miter in steam pipe
Para 104.3.3 (A.3)stated that miters may be used only if "The contained fluid is nonflammable, nontoxic, and incompressible, except for gaseous vents to atmosphere"
Since steam is a ompressible fluid, if follows that miter is NOT permitted.
RE: B31.1 allowable miter in steam pipe
RE: B31.1 allowable miter in steam pipe
RE: B31.1 allowable miter in steam pipe
RE: B31.1 allowable miter in steam pipe
We apply C.1 based on many years using mitres for steam line up to 60". We have a low number of load cycles.
RE: B31.1 allowable miter in steam pipe
Regards