Flow Rate and Pressure Changes when a Reducing Valve Fails

[DMay121]

I am verifying the integrity of a pressurized piping system that is utilizing GHe. The inlet pressure is 2400 psig, and the outlet pressure is 200 psig. I am trying to analyze how the pressure on the outlet side will change if the pressure reducing valve fails. The relief valve on the outlet side has a set pressure of 230 psig, and at that pressure it can offload 220 scfm.

Can I use relief valve sizing calcs to determine the scfm through the regulator if it fails? And if so, how can I calculate the resulting pressure change that would result from the excess scfm assuming the relief valve can't offload the entire flow rate through the failed regulator?

Thanks,
David

 

[georgeverghese]

Another alternate solution to replacing this regulator would be to add another regulator upstream to break the pressure down to a value that will bring this existing regulator back into its controllable range, and keep within the PSV relief capacity at 1.1x LP side design pressure. Preferably pilot operated also. Agreed this option may be more troublesome than a straightforward replacement of the existing regulator.

 

[Latexman]

Or add an orifice or flow nozzle u/s or d/s of the regulator to limit the flow less than the capacity of the PSV.

Good luck,
Latexman

Technically, the glass is always full - 1/2 air and 1/2 water.