Case leak and stud failure on multi stage split case pump BB3

[Mech5656]

Hello,
We have a split case pump here with max running temp of 240F and discharge pressure of 1500psi. The case leaked from the center and the stud in that area broke when it was running. Attached is picture of what we found. The gasket is gone in the center area while it was running. Have you see something like this? What can cause this? Can you recommend solutions so this doesn’t happen again?

 

[TugboatEng]

The gasket appears to be your typical aramid/rubber compressed fiber gasket. Most commonly these gaskets use nitrile rubber (Garlock 3000 for example) as a binder. 240° is too high for nitrile rubber when water is present. You should consider switching to a gasket with an EPDM rubber binder (Garlock 3700 as an example) if the pumped fluid is water.

Even better, go gasketless.

 

[mk3223]

What it means....

The gasket is gone in the center area while it was running.

1st - Verify is "gasket" was installed.
2nd - Check if correct gasket for the application
3rd - How long the equipment was in the service? And, if the equipment had any issue during the testing and/or startup process?

Suggest to involve the Ops and Maintenance with Engineer and pump vendor to investigate the incident and identify the root causes, and then, decide the proper solution to fix it.

 

[Artisi]

Analyse the stud failure as well as gasket material selection.
Check casing halves for straightness / warped etc.
Check remaining studs, or dump them all for new ones.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[quadtracker]

I would check the flatness of the casing halves looks like the fluid has washed out the gasket area. Improper torque sequence and value could be a factor. Improper gasket material. Gaskets must be hand fitted and cut at the very edges of the casing otherwise high pressure fluid will erode the gasket. All casing edges must be sharp to insure gasket sealing integrity. Looking at the stud holes, the gasket was not hand fitted but factory cut leaving metal areas exposed, if this gasket was a poor fit down the center rotor area then high pressure fluid will erode the gasket area.