relief valves 1

[roker]

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?

 

[josephn16]

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).

 

[roker]

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

 

[TD2K]

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).

 

[yulinios]

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