Using pressure relief valves in series to increase cracking pressure

31 March, 2025

This works because when the first valve begins to open, the downstream pressure remains insufficient to open the second valve. The pressure equalises on the back of the first valve, causing its spring to resist further opening. Only when the pressure increases to the sum of both valves’ cracking pressures do both valves open simultaneously, with each experiencing its own pressure drop.

This method is particularly useful in the design of downhole oil tools, where precise pressure control is critical. The Lee Company manufactures 0.281-inch diameter high-pressure relief valves with cracking pressures of up to 5,900 psid. When used in series, these valves can achieve a combined cracking pressure as high as 11,800 psid. For ease of installation, both valves can be housed within the same mounting hole using a Dual Insert Adaptor, as detailed on page N25 of the 12th Edition of the Lee Technical Hydraulic Handbook.

For further information please visit:

https://www.theleeco.com/industries/oil-gas/products/pressure-relief-valves/

https://www.linkedin.com/company/the-lee-company/