Today, the editor will share the sealing failure modes of O-rings and corresponding countermeasures.
O-ring sealing principle
In general, O-rings achieve reliable sealing effects through the mechanisms of compression deformation, closed sealing, and expansion and rebound. This simple and effective sealing principle makes O-rings widely used in various mechanical equipment and industrial fields.
Commonly used O-ring shapes and characteristics
Commonly used materials
O-ring failure forms and countermeasures
Common failure causes of O-rings include material problems, compression deformation, gap bite, distortion, abrasive damage and improper surface roughness.
Confirm before installation
1. Is the lead-in angle processed according to the drawing?
2. Is the inner diameter deburred? Are sharp edges rounded?
3. Have processing residues, such as debris, dirt, foreign particles, etc., been removed?
4. Is the thread tip covered?
5. Have seals and parts been coated with grease or lubricating oil? (Media compatibility with the elastomer must be ensured. It is recommended to use the sealed fluid for lubrication.)
6. Grease containing solid additives, such as molybdenum disulfide and zinc sulfide, must not be used.
Pay attention during installation
1. Use tools without sharp edges;
2. Ensure that the O-ring is not twisted and use auxiliary tools to ensure correct positioning;
3. Try to use installation auxiliary tools;
4. Do not overstretch the O-ring;
5. For O-rings bonded with sealing strips, they must not be stretched at the connection.
O-rings are threaded and splined for installation
When the O-ring is stretched and needs to pass through threads, splines, keyways, etc., an installation mandrel must be used. The mandrel can be made of softer metal or plastic and must not have burrs or sharp edges.
