4 replies to this topic

[nafeesknp]

We have Liquid Ethylene Line operating pressure 53 barg and pipe design pressure is 62.4 barg. Thermal Relive valve installed on it, what should be th eset point of TSV? same as design pressure 62.4 barg or some thing else. what standard says?

[latexman]

You never told us what standard you are using, so how do we know?

Edited by latexman, 21 July 2016 - 01:53 PM.

[Pilesar]

You should find the applicable standard to read and understand for yourself. My outdated copy of ASME piping standard B31.3 allows the set pressure for a thermal relief device which only protects a blocked in portion of pipe to be no higher than the lesser of the piping system test pressure or 120% of design pressure. 

[christopherchoa]

API 520 Part 2 will definitely help you. The newest version expanded the thermal relief.

 

For most thermal PSVs, the set pressure is the same as the design pressure of the pipe unless the relief valve is far from the pipe being protected.

[fallah]

nafeesknp,

 

As Pilesar mentioned, design code will dictate the matter hence if B31.3 is the governing code the set point will be what Pilesar mentioned otherwise the set pressure can be equal to or lower than pipe design pressure...