The MAWP of a boiler is 900 psi and the...

Question 1 of 270705eccefa0bacbc34ba4d46d65

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 _______.

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Question 1 of 27070

🔍 Key Concepts

• MAWP (Maximum Allowable Working Pressure) of the boiler and what Coast Guard regulations say about safety valve settings relative to MAWP • Relationship between drum safety valves and superheater safety valve settings, especially considering the pressure drop across the superheater • How the normal pressure drop across the superheater (20 psi) affects the drum pressure when the superheater safety valve lifts at 825 psi

💭 Think About

• If the superheater outlet safety valve is set at 825 psi and there is normally a 20 psi drop across the superheater, what pressure does that imply at the boiler drum when that valve lifts? • How close to the MAWP are you allowed to set the highest safety valve under Coast Guard regulations, and how does that constrain the minimum setting for the drum safety valves in this case? • Compare the implied drum pressure (from the superheater setting + pressure drop) with the answer choices; which choice keeps you within MAWP limits while also respecting the required relationship between drum and superheater safety settings?

✅ Before You Answer

• Calculate drum pressure = superheater setting + normal drop and compare that value to the MAWP of 900 psi • Verify that the highest safety valve setting cannot exceed MAWP under Coast Guard/ASME/USCG requirements (and is typically limited to a small percentage below it) • Check that the chosen answer does not cause drum pressure above MAWP when the superheater safety valve lifts and that it maintains the correct pressure hierarchy: drum safety valves vs. superheater safety valve