2 replies to this topic

[asade abiodun]

Good day All,

I am designing a PRV on the discharge line from a compressor. I considered block outlet as the worst relieving scenario. The relieving load is taken as the expected flow rate through the compressor. The PRV will be installed downstream of the discharge air-cooler, upstream of the anti-surtge line connection.

The challenge i am having is that if i connect the PRV outline line to the flare line, it would result in large flare header, large flare KO drum and large flare stack because of its load.

What is the implication if i connects the PRV discharge outlet into the compressor train suction line upstream of the suction scrubber? OR what other method should one consider to avoid designing a massive flare system.

Compression Data:
Flow rate - 1750 MMSCFD
Compressor suction pressure: 850 - 900 psig
Gas inlet temperature: 25 - 35 deg. C
Compressor discharge pressure: 1250 psig at 65 deg.C
Expected outlet pressure from air-cooler- 1240 psig.

I would appreciate your technical response in solving this problem.

Regards

[ankur2061]

asade,

I am attaching a reference which recommends that the compressor PRV should not be routed back to the suction of the compressor.

Hope this helps.

Regards,
Ankur.

Attached Files

•  Compressor_Pressure_Relief.doc   22KB   458 downloads

[asade abiodun]

Thanks Ankur,

I appreciate your response. Since the PRV relief is not advised to be resend into the suction line, then the flare system would be designed to handle the relief load from the compressor because it the scenario that provides the maximum expected relief load from the booster station.

Like i said in my earlier post, this will result in resizing the flare KO drum, Flare header and other system.

Thanks.