Question 33Safety & Environmental - 1st Asst/Chief

The correct answer is C) 14.2 psia and 2 psig. Pressure-vacuum relief valves on tank vessels are typically set to operate between 14.2 psia (pounds per square inch absolute) and 2 psig (pounds per square inch gauge). This range is specified in the regulations governing the design and operation of these valves, as it ensures the tank is protected from both overpressure and excessive vacuum conditions. The other options are incorrect because A) references operating below atmospheric pressure, which is not the typical range, and B) and D) specify ranges that do not align with the regulatory requirements.