Question 186Steam Plants - Assistant Engineer

The correct answer is A) 46 CFR require that if there is a pressure drop of 10 psi, the superheater safety valve set at 450 psi must open to relieve the pressure. According to the Code of Federal Regulations (CFR) for the US Coast Guard, specifically 46 CFR, the regulations state that a superheater safety valve must be set to lift at a pressure no higher than 103% of the maximum allowable working pressure of the superheater. In this case, with a set pressure of 450 psi, a 10 psi drop would be within the 103% limit, causing the valve to open and relieve the pressure as required by the regulations. The other options are incorrect because B) is not a complete answer, C) is the metric equivalent of the set pressure rather than the regulatory requirement, and D) is higher than the 103% limit specified in the regulations.