Waste caustic relief to flare header

[liquidaim]

Hello all,

I am in the process to installing a PSV on a spent waste caustic header with relief to a nearby flare header.

Is it ok to relieve liquids into the flare header? There is a separator in the flare system near the flare stack.

One concern might be corrosion of the flare header, but the flare lines should be oxygen free and we shouldn't have corrosion taking place if there is water but no oxygen in the line.

Any thoughts?

Thank you

 

[ajs1972]

Obviously, liquids can´t come to flare, but you need to review the design of your separator. Maybe you need a quench tank in order to receive all the condensate and the liquids of the relief.

Review the Chemical Engineer Handbook from Perry in the Chapter 26 (Process Safety) in the section: "Emergency Relief Device Effluent Collection and Handling" and take a look of the equipment and their design for handle the effluent discharged.

 

[ajs1972]

Other things that you need consider are: from where the header receives the reliefs? Because the presence of liquids in header could increase the backpressure of the some emergency relief system from another equipment that needs release pressure and cause an accident or explosion.

 

[TD2K]

Some flare tips can handle liquids, Coanda's is one but I agree, the bulk of flares out there are not designed to handle liquids.

Relieving liquids to the flare is not preferred but does happen.