Overpressurize the M-Seal!!

[Ayden]

How is it possible to overpressurized a Mechanical Seal?
When Starting a pump? Turning one out? By starting the third one?
If I have the suction valve open, fluid should flow to lower pressure area right?

Any help would be appreciated... Thanks

 

[tonyh]

Lots of different possibilities - you name it - it can be done.
Most commonly in my experience is pressure surge in the line from a fast acting valve - but start and stop with valves wide open is a possibility. Blocked in pump with thermal expansion is also a possibility. If you have designed the pump system properly (another set of possibilities there) you should not be able to overpressure the seal from normal operation. However, if the seal is not rated for the maximum discharge pressure of the pump (pressure in stuffing box is lower) and it is possible to get reverse pressure from the delivery with the suction valve closed, this also will provide overpressure. Your question implies that you have multiple pumps so this is a possbility.

 

[scalleke]

Should it be possible to overpressurise the machanical seal?

The manufacturer should have given you proper start up procedures to make sure that that can not happen.

What type of seal configuration do you have? Tandem and you do not have buffer pressure ???

In any case, if you follow manufacturers recomended operation procedure it should not be possible to overpressurize. but to dtermine what is the problem we need to know the type of pump, the type of installation, the type of seal, the seal configuration and the circumstances under which the seal failed.

Best regards,

Scalleke