What is the relief valve setting on a propane cylinder?

What is the relief valve setting on a propane cylinder?

• A. 275 psig
• B. 300 psig
• C. 350 psig
• D. 325 psig

Answer: (C)

Relief devices on propane cylinders are a safety buffer that vents gas whenever the internal pressure gets too high. Propane in a cylinder is partly liquid and the vapor pressure rises with temperature; as heat or overfill pushes pressure up, the relief valve opens at a predefined setpoint to prevent the cylinder from overpressurizing and potentially failing. For standard propane cylinders, that setpoint is about 350 psig. This value is high enough to stay closed under normal use, yet low enough to relieve before the cylinder reaches its critical design limit, protecting the cylinder from rupture in hot conditions or if overfilled. Other pressures would either vent too early under normal conditions or not vent quickly enough in overpressure situations, so 350 psig is the typical, appropriate safety setting.

Relief devices on propane cylinders are a safety buffer that vents gas whenever the internal pressure gets too high. Propane in a cylinder is partly liquid and the vapor pressure rises with temperature; as heat or overfill pushes pressure up, the relief valve opens at a predefined setpoint to prevent the cylinder from overpressurizing and potentially failing.

For standard propane cylinders, that setpoint is about 350 psig. This value is high enough to stay closed under normal use, yet low enough to relieve before the cylinder reaches its critical design limit, protecting the cylinder from rupture in hot conditions or if overfilled. Other pressures would either vent too early under normal conditions or not vent quickly enough in overpressure situations, so 350 psig is the typical, appropriate safety setting.