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relief valves

relief valves

relief valves

(OP)
how should be calculated the temperature at the outlet pipe from a relief valve for vapor/gas flow in case of fire or power failure?
is there a temperature gradient along the outlet pipe till the flare header?

RE: relief valves

roker,

I'm not sure of your application, but, normally, if there is a danger of heat and/or gas from a relief valve, the practice is to vent to the outside or to the stack (in the case of a furnace).

RE: relief valves

(OP)
hello Josephn16,

what i ment is for example if a relief valve is set to 20 barg and 200 deg C what will be the temperature at the outlet of the relief valve when vapor or gas are discharged from the relief valve.

regards

RE: relief valves

Do an adiabatic expansion on the gas starting with the inlet conditions.  You'll need a simulator or a Mollier diagram to estimate the outlet temperature on expansion.  

A rule of thumb for cooling on expansion is about 7 deg F per 100 psi I believe (do a keyword search on the site, this has been discussed quite a few times).  

RE: relief valves

Hi:

I thing that one way to estimate that temperature is getting entalphy from a Molliere Diagram as TD2K said, after that you can get the oulet temperature with 1 Bar (atmospheric pressure), starting with 20 barg and 200°C I got 160°C, assuming that the entalphy is constant.

Bye There

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