Description

Pressure relief valves are a critical component of an aircraft's fuel, hydraulic, and pneumatic systems. These valves serve one of three functions - safety relief, pressure regulation, or protection against thermal expansion.

Safety relief valves

Safety relief valves are designed to be fast-acting components that protect systems with the potential for sudden pressure spikes. These valves may sit dormant for indeterminate amounts of time before needing to be used, so it’s crucial that they always work as intended.

Pressure regulating relief valves

Unlike safety relief valves, pressure regulating valves operate more frequently. These valves compensate for momentum forces that upset the normal force balance of typical direct acting valves.

Thermal relief valves

When traveling from the cold at an altitude of 30,000 feet to a runway in the desert, rapid temperature change can cause thermal expansion of fluids and potential damage within the system. Thermal relief valves are designed to relieve small volumes of fluid to protect against thermal expansion.