Question 178Steam Plants - Assistant Engineer

The correct answer is B) 850 psi. According to Coast Guard regulations, the drum safety valves must be set to lift at a pressure not exceeding 95% of the MAWP of the boiler. In this case, the MAWP of the boiler is 900 psi, so the minimum setting of the drum safety valves must be 95% of 900 psi, which is 850 psi. The other options are incorrect because A) 825 psi is below the 95% threshold, C) 875 psi is above the 95% threshold, and D) 900 psi is the MAWP itself, which is not allowed as the minimum setting for the drum safety valves.