O-rings typically fail in their applications because of the combined adverse effects of several environmental factors.
The most common causes of O-ring failure have been found to be:
- Improper gland design; allowing for too much or too little compression, not enough room for seal expansion, and tolerance stack-up.
- Incorrect O-ring size.
- Incompatibility of O-ring elastomer and environmental elements.
- Improper O-ring installation.
- Inadequate O-ring lubrication.
The combination of stresses on the O-ring can be complex and difficult to evaluate. Therefore, it is very important that both the O-ring compound and size be tested in the real environment of its service. The following examples are a classification of the types of O-ring failure that can occur.