Plan 52 buffer fluid changing

[aalexsantoss]

From my understanding, API has recommendations on the frequency to refill 53s. However, it seems that changing your 52 fluid is ona case by case basis. At my refinery, they never change the oil in the 52s and run the pumps until failure. After failure, they clean the pots out and put in fresh fluid. The pots get pretty nasty after 2 years of service with no change of the fluid.

My question is, what are some general guidelines (other than look at the pot to see color of fluid) that you guys use to determine when to change the fluid? I have read some API documents that says get samples of the fluid from time to time to check the quality and assure no degradation, but i can guarantee they wont do that here.

I have stated to try and change the fluid in the pots every 6 months to maximize seal performance.

Thoughts?

 

[Pumpsonly]

For Plan 53s, because the barrier fluid is pressurised, it does not get contaminated by the pumped liquid. You refill it when the pressure is almost reaching the the seal chamber pressure.

For Plan 52,the pump liquid gets into the reservoir and mixed with the buffer fluid. If the pumped liquid is non flashing, it will remained in the pot and mixed with the buffer fluid.
So you have to monitor the condition visually or analytically.

 

[JJPellin]

We have PM tasks to change the barrier fluid in all Plan 52 pots every 6 months. If we fail emissions testing (LDAR sniffing), our first attempt is always to change the barrier fluid. Our most common barrier fluid is a high temperature synthetic oil. We used to use #1 fuel oil as our most common barrier fluid. The synthetic oil is much more expensive, but we have seen much better reliability with this barrier fluid. We have a few pots that used 50/50 ethylene glycol.

Johnny Pellin