A device actuated by inlet static pressure and designed to open during an emergency or abnormal condition to prevent a rise of internal pressure in excess of a specified value. In operation, the pressure relief valve remains normally closed until pressures upstream reaches the desired set pressure. The valve will crack open when the set pressure is reached, and continue to open further, allowing more flow as over pressure increases. When upstream pressure falls a few psi below the set pressure, the valve will close again.
For selection of the pressure relief valve, it is important it consider the expected relief pressures, flow rate, port configuration, effective orifices, material of construction.
