Effect of relief load on Flare KO Drum sizing

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It was considered that inadvertent closure of the compressor discharge outlet valve can cause system overpressure. If this occurs, a PRV was designed to relieve the gas into the flare system. The relief load is equivalent to the gas flow rate through the compressor. This relief load gives the highest worst case load expected at the compressor station.

The design conditions for the Flare KO drum is stated below:

Relief load: 1750 MMSCFD (1,617,236.51 kg/hr)
Design KO drum pressure: 50 psig
Gas MW: 18.51
Temperature: 65 deg.C
Gas compressibility: 0.880

Liquid flow rate: 16,172.37 kg/hr
Liquid density: 550 kg/m3


Please, I need your engineering guidance on how to design a flare KO that can handle this type of flow rate because the size i obtained look outrageous to me (50 m Length and 6m dia.).

also, what is your line of thought if we rely on the PSH on the compressor discharge line to trip off the compressor when it detects high pressure?

What if the PRV is sized only to relief the gas volume that would be contained in the discharge piping?

The MAWP of the discharge piping can handle the maximum shut-in pressure from the compressor.
Normal discharge pressure from compressor = 1250 psig
Maximum shut-in pressure from compressor performance curve = 92.5 bara ( 1327 psig)

Please, I would appreciate your anticipated response to that I can make headway with this design.