USCG Exam PracticeBoiler and steam propulsion fundamentals
Under 46 CFR §56.50-30, what design pressure must feed piping from the boiler — to and including the required stop and stop-check valves — be rated for, relative to the boiler's maximum allowable working pressure (MAWP)?
- A. Equal to the MAWP of the boiler
- ✓ Exceeding the MAWP by either 25 percent or 225 psig, whichever is lessCorrect
- C. Exceeding the MAWP by either 25 percent or 225 psig, whichever is greater
- D. Equal to the feed pump relief valve setting regardless of boiler MAWP
Why B is correct
46 CFR §56.50-30(a)(3) specifies that feed piping from the boiler, to and including the required stop and stop-check valves, must have a design pressure that exceeds the MAWP of the boiler by either 25 percent or 225 psig, whichever is less. The 'whichever is greater' option would impose a more severe requirement than the regulation states.
Cited:46 CFR §56.50-30