USCG Exam PracticePumps, valves, and piping systems
When a piping system contains a component—such as a valve or fitting—whose maximum allowable working pressure is lower than that computed for the pipe itself, what does 46 CFR §56.07-10 require?
- A. The component must be replaced with one rated to match the pipe's computed pressure
- ✓ The system pressure must be limited to the lowest maximum allowable working pressure among all componentsCorrect
- C. A relief valve must be installed immediately downstream of the lower-rated component
- D. The pipe wall thickness must be increased to reduce the computed pipe pressure to match the component rating
Why B is correct
46 CFR §56.07-10(a)(2) requires that where the maximum allowable working pressure of a system component is less than that computed for the pipe or tubing, the system pressure must be limited to the lowest of the component maximum allowable working pressures. Replacement or wall-thickness changes are not mandated by this provision.
Cited:46 CFR §56.07-10