8-11 Mechanical Seal design, operation, and maintenance practices that cause seal, pump and bearing problems

In my seminars I teach that mechanical seals fail prematurely because:

In the following paragraphs we will learn how these failures can be separated into:

These individual subjects have been discussed in other sections of this Technical Series. The purpose of this paper is to give you an overview of the subject, and assist you in your troubleshooting function.


Problems with the Seal Faces:

The Springs or bellows.

The Dynamic Elastomer (the one that moves)

Operating conditions too severe for the design.

Dual seals

Design problems that cause excessive shaft movement

The pump is cavitating due to a design problem.

Other design problems

Problems caused by the product you are sealing.


Operations that cause excessive shaft movement that will open or damage the seal faces

Operations that cause excessive heat and corrosion problems

Operations that cause the seal faces to open



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