This is the second tip in a two-part series on seals. Last week, we covered basic seal types and design. This week, we’ll take an even closer look at design and also discussed seal wear.
Seal design: An in-depth look
When designing a seal, choosing the correct material is essential to proper operation. Seal materials include:
The choice of seal type and design is influenced by the lubricant chosen, specifically grease or oil and the additives they contain:
Proper seal design and choice is critical to achieving maximum component life when lubricating rotating equipment.
The most common cause of seal wear is improper selection, particularly failure to consider the operating or environmental temperatures. With static seals, the polymers used may dry out with age and lose their memory. When that happens, leakage occurs and it is time to replace the gasket or o-ring. Mechanical seals, being more complex, can suffer from many different types of wear. These include:
It is difficult to state causes of shaft seal failures exactly without performing a root cause failure analysis. This would include a look at the shaft seal, rings, elastomers and other parts, in addition to knowing the operating and environmental conditions.
If it’s not already obvious, seals are super important. They are designed to not only keep the lubricant in but also to keep environmental factors out. Just 0.002% water entering a bearing will cut the rated life by 50%, so clearly proper seal selection impacts productivity.
I hope you enjoyed reading this tip as much as I did creating it. If you have any questions, leave them in the comments section below. Thanks for reading!