Pressure relief valves are safety devices that secure the pressure system from over-pressurization. Its function is to control the pressure at all times to ensure the safety of life and property. When the system is subject to excess fluid or gas, the valve opens, allowing the excess fluid/gas to divert to an auxiliary passage. This relieves the pressure in the system. The Pressure relief valve acts as the "path of least resistance, " allowing the extra fluid to be diverted. For More Info:- https://www.mgacontrols.com/what-is-a-pressure-relief-valve/