Maximum Relief Temperature

[BNJR]

I´m a junior engineer and i´m introducing myself to "amazing" psv world.

I´m having problems with determining maximum temperature for each relieving case.

Is there any general tip for calculating temps for different scenarios?

Thank you in advance

 

[MortenA]

If you are referring to fire case with a wetted vessel then the releiving temperature is equal to the boiling temperature of you liquid at the releiving pressure (incl 21% overpressure if you are working with API520.

Best regards

Morten

 

[alsayed]

In the oil industry usually we keep the stream temperature for the rundown 20F lower then the flash point temperature of that hydrocarbon stream. But in RV you have to consider the firing case when the PSV or RV should be sized to handle a fire case scenario in the vessel. The liquid will combust to gas and the volumetric rate will just shoot up. So if you are designing for a fire case you should consider the combustion temperature.

But if it is just a normal pressure releasing valve like in cooling water heat exchanger or water vessel as a safety measure for the equipment. Then the design temperature will be just the max process temperature expected.