Question 248Steam Plants - 1st Asst/Chief

The correct answer is A) 50 pounds higher than the drum safety valve plus the water pressure drop through the economizer. The economizer relief valve should be set 50 pounds higher than the drum safety valve to ensure that the economizer is protected from overpressure. The additional pressure drop through the economizer must also be accounted for, so the relief valve is set higher than the drum safety valve by that amount. The other options are incorrect because: B) the economizer relief valve should not be set in relation to the superheater safety valve, C) it should not be set at the same pressure as the superheater safety valve, and D) it should not be set at the same pressure as the drum safety valve, as that would not provide the necessary overpressure protection for the economizer.