What is the minimum blowback on a safety valve that pops at 250 psig?

The minimum blowback on a safety valve that pops at 250 psig is determined by the standards set for safety valve performance, which typically require a certain amount of blowback to ensure proper operation. For a safety valve that is set to pop at a specific pressure, such as 250 psig, there is an industry standard that mandates the blowback or reseating pressure to be a certain amount above the set pressure.

In the case of a valve set at 250 psig, the minimum blowback is established to be at least 5 psig above the popping pressure. This means that the valve must be able to reopen and reseat correctly after the pressure has been relieved, which ensures the system remains safe and operational. The 5 psig value ensures that the valve does not continuously leak or fail to reseat, thus efficiently managing pressure within the system and preventing dangerous overpressure conditions.

This requirement is crucial for maintaining the safety and reliability of the system since it prevents the valve from being inadvertently activated by minor pressure fluctuations and ensures it operates correctly under expected conditions. It guarantees that the valve functions as intended, thereby protecting both the equipment and personnel involved.