Complete failure can occur in destructive scenarios like severe surge, but can also occur if the outer secondary seal has failed but the failure has not been detected. A subsequent failure of the primary seal will then release gas to atmosphere. Secondary seal failure can be caused by oil...
You would use plan 52 when contamination of the buffer fluid with the pumped fluid is acceptable; as raronen states a plan 52 is generally simpler.
For example I have seen plan 52 on a heat transfer fluid circulation pump, where to avoid carbon buildup it was important to keep air away from the...
This is a big subject! I think Steve has the right direction.
For some useful info on good fitting practices, read ESA / FSA Publication No. 009/98
Guidelines for safe seal usage
-Flanges and Gaskets -
Are the thermal growth assumptions contained in the vendor alignment specs valid? They will be based upon an assumed cold condition and temp rise to operating temp which may not be valid. Can set up laser to measure actual relative thermal growth of bearing housings which will validate the cold...
We have an (old) electric driven recip pump in this service from Duraqual, try www.pumpingequipment.com.au. Not sure of their packaging experience/capability for diesel drives though.
Good luck.
I have come across turbo-expanders used in natural gas plant applications - try contacting www.mafi-trench.com. They should be able to help you or suggest other mfrs if they aren't into this application.
40 to 90 seconds suggests that the bearing is starting dry and may stay dry due to the heat generated by contact friction.
You are dealing with a high vapour pressure fluid, and unless the bearing is designed to run dry you need to ensure that it remains a liquid all the way through the bearing...
This posting is a little late, but here goes anyway....
We have experienced a failure of both primary and secondary seal on a gas compressor, but I suspect that the outboard seal had already failed, and we had not picked it up due to problems with our detection instrumentation.
monaco8774 we...
Suggest that you contact the mechanical seal vendor, as they should be able to advise expected leakage rates for the specific application, and provide guidance on what leakage rate indicates serious damage to the seal.