The maximum allowable working pressure (MAWP) of a boiler is determined by the strength of the weakest part of the boiler. A boiler may not be operated above its MAWP.
The MAWP on the shell or drum is determined by the following formula:
MAWP = TS x t x E
Where
TS = 55,000 (lbs/sq in)
t = minimum thickness of the plate (in inches)
E = efficiency of the joint (nondimensional), as set forth in Appendix A at the end of this chapter
R = inside radius of the shell (in inches)
FS = safety factor of 5.0 (nondimensional)
S.D. Admin. R. 61:08:09:13
General Authority: SDCL 34-29A-14.1.
Law Implemented: SDCL 34-29A-14.1.