A pressure relief valve includes the following features. A housing defines an inlet and an outlet. The housing defines a flow passage between the inlet and the outlet. A seat can be defined by the housing. The seat defines a throat flow area. A plunger is configured to rest upon the seat. The plunger blocks the flow passage when in a closed position. The plunger is configured to actuate between a fully open position and the closed position. The plunger and the seat can at least partially defining a curtain flow area. A bias directs the plunger towards the seat. A ratio of the throat flow area to the curtain flow area is sized for sonic or supersonic flow velocities during critical flow conditions and subsonic velocities during subcritical flow conditions.

A pressure relief valve includes the following features. A housing defines an inlet and an outlet. The housing defines a flow passage between the inlet and the outlet. A seat can be defined by the housing. The seat defines a throat flow area. A plunger is configured to rest upon the seat. The plunger blocks the flow passage when in a closed position. The plunger is configured to actuate between a fully open position and the closed position. The plunger and the seat can at least partially defining a curtain flow area. A bias directs the plunger towards the seat. A ratio of the throat flow area to the curtain flow area is sized for sonic or supersonic flow velocities during critical flow conditions and subsonic velocities during subcritical flow conditions.