Question 143Steam Plants - 1st Asst/Chief

The correct answer is C) 300 psig. According to Coast Guard regulations, the minimum pressure required for the pressure relief valve on a boiler or unfired pressure vessel is 300 psig (pounds per square inch gauge). This requirement is in place to ensure the safety of the equipment and prevent potential accidents or explosions. The other answer choices are incorrect because A) does not specify a pressure requirement, B) refers to a different unit of pressure (kilopascals), and D) is not a valid answer choice.