1 reply to this topic

[alxthms]

Hey guys, first post here. I've been working as a process engineer in the PSM field for a few years now.

 

My group came across something that has even stumped our PSV SME so I thought I might pitch the situation on this forum. What we have is a conventional relief valve (Mercer 91 series 1/2" D 1" set at 1,650 psig) drilled into the dome of a pilot (Mercer 95 series 4" x 6" set at 1,440 psig) which protects a compressor suction header coming from an inlet coalescing filter. We cannot think of any credible overpressure scenario for the pilot but the conventional valve's original purpose is a mystery I'd like to figure out. Operations and the site engineers have no clue and of course there's zero documentation on its sizing. I've attached a few pictures.

 

Any ideas? It cannot be meant to be the pilot valve to depressure the dome since clearly there already is one plus the set pressure of 1,650 psig makes no sense in that regard. This problem is more of a curiosity thing now since we've flagged the valve to be replaced.

 

 Arrangement Picture.JPG   233.81KB   9 downloads

 

 PSV-WD1.JPG   79.09KB   5 downloads

 

Thanks!

 

-Alex

[latexman]

Ask Mercer, and let us know if they answer.