Question 178Steam Plants - Assistant Engineer70% to pass
The MAWP of a boiler is 900 psi and the normal drop across the superheater is 20 psi. If the superheater safety valve is set to lift at 825 psi, the minimum settings of the drum safety valves allowed by Coast Guard Regulations would be _______________.
AI Explanation
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.
Related Questions
#176 A heavy accumulation of soot on the fireside of the superheater can cause a _______________.#177 Coast Guard Regulations #179 If the maximum steam generating capacity of a boiler is increased Coast Guard Regulations #180 Coast Guard Regulations #181 Coast Guard Regulations, 46 CFR Part 54, require steam safety and relief valves to be provided with a substantial lifting device, capable of lifting the disc from its seat at what percentage of the set pressure?