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 (ininches)

E = efficiency of the joint (nondimensional), as set forth in Appendix A at the end of this chapter

R = inside radius of the shell (ininches)

FS = safety factor of 5.0 (nondimensional)

Source: 23 SDR 139, effective March 5, 1997.

General Authority: SDCL 34-29A-14.1.

Law Implemented: SDCL 34-29A-14.1.