The major reason for mechanical seal Failure is that the seal was run dry and over heated. Other reasons that I have come across are that it was dead headed " forced to run against a closed discharge valve" and the seal was the only outlet for the pressure. The last but not least was that the nut holding the impellor is loose or came off altogether and the lack of pressure on the seal " normaly 3/8"".
Depending on what is being pumped wear can be a factor as well. On one system I deal with CMP slurry is part of the waste stream being pumped. CMP does a fine job of accelerating the wear of seals. I would suspect that other abrasive meterials would have the same effect.
But being ran dry would definitely be at the top of the list.
Just depends, are you talking runtime failuire (seal fails after running 1000 hrs) the answers everyone is giving are good then, if it startup failure look at runout of shaft and excessive crush on seal.
From my experiance, if the pump shaft runout is more than the accebtable limits (i.e our Standard limits should be < 0.0025") at the coupling hub and face. This is considered excessive and is very likely to be the main contributory factor towards the repeated failure of the drive end mechanical seal and bearing.
Mechanical seal
Re: Mechanical seal
