What are possible causes for mechanical seal leaking?

[Mech5656]

Hello Dear Engineers,

I am not working on specific pump but I have a general question about seal leak in pumps. I am looking for a matrix or checklist for possible seal leak reasons. Do you have or mind sharing this document or book you can refer? Basically, I am trying to narrow down root cause for sea leak or any other seal problem will be best. Thanks

 

[3DDave]

Seals leak because there is either a discontinuity in the contact between the seal and the mating surface, there is less contact pressure between the seal and the mating surface (considering surface adherence in the case of fluids) than the fluid pressure, or the seal itself has developed a discontinuity such as a crack.

There are plenty of causes for each of these to occur, but it will depend too much on the exact circumstance to avoid an infinite book of the infinite possibilities they may take.

Usually one contacts the pump maker and the seal maker to see if they have experience they would like to share.

 

[TugboatEng]

Don't forget about failures elsewhere in the seals including the bellows, spring breakage, and stationary seat to housing seals.

 

[EdStainless]

I believe that Crane seal has published troubleshooting guides for mechanical seals.
Contact you favorite seal supplier and ask for general troubleshooting information, most of them have training materials in this subject.

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P.E. Metallurgy, consulting work welcomed

 

[bimr]

1. ALLOWING THE PUMP TO RUN DRY

2. VIBRATION

3. HAMMERING COUPLINGS ONTO THE SHAFT

4. OPERATOR ERROR

5. IMPROPER USE OF, OR COMPLETELY OMITTING MECHANICAL SEAL FLUSH PLANS

6. SELECTING THE WRONG MECHANI¬CAL SEAL OR MATERIALS

Why mechanical seals link

 

[georgeverghese]

Selecting the right seal and the barrier flush plan is a right pain in the neck till you get everything sorted out, so expect a rough ride. It gets much worse when you have project cost controllers and project managers thrown into the pot. Problems I've come across are poor, incomplete and conflicting info from seal vendors, conflicts of interest between seal supplier and pump supplier, and interface issues between process and mechanical engineers, sometimes extending to electrical engineers also. Unfortunately, "minor details" such as seal systems for pumps dont sufficient attention from design engineers or from the Plant Owner at conceptual design phase.