Dear Experts,

A vessel is designed for external pressure of 50 psi and per contract it is requierd to be code stamped (U).

Questions
1. Does it need a relief valve.
2. If yes, please provide code para reference.
3. What should be the set point and overpressure of this RV.

Thanks.

Jagdev,

Pressure relief valve is a protection against internal over pressure and its set pressure shall be based on the internal design pressure/ MAWP of the equipment.

You may require a Pressure-Vacuum valve if need protection from failure due to vacuum.

Regards