Troubleshooting
The table organizes general failures while using O-Ring and their responses.
| Failure | Description | Cause | Response |
|---|---|---|---|
| Stick-out |
If fluid is put under high pressure, o-ring sticks out from groove.
|
1) Pressure is too high. 2) Groove is too large. 3) Back up ring is not transformed. |
1) Narrow the groove. 2) Increase rubber hardness. 3) Transform Back up ring. |
| Permanent compression transformation |
Compressed part is flattened out.
|
1) Temperature is too high. 2) The material used has a low permanent compression transformation ratio. 3) Lack of curing in o-ring |
1) Change to a material with high permanent compression transformation ratio. 2) Cool down the seal part. |
| Oxidation and heat-cause hardness |
Rubber becomes hard initially from the surface later to the whole cross-section. Permanent compression transformation follows.
|
1) Temperature is too high. 2) Rubber material is cross-linked and plasticizer evaporates. |
1) Use a material with good performance at high temperatures and heat resistance. 2) Lower the temperature of operation. 3) Keep the surface away from oxygen. |
| Plasticizer extraction |
Volume decreases.
Dimensions decrease.
Rubber becomes hard.
|
Plasticizer inside rubber is extracted by surrounding liquid, grease, etc. | Use a rubber material containing plasticizer in less quantity or hard to extract. |
| Abrasion |
Linear abrasion is created in parallel with movement on the other contact side.
|
1) The other surface is too rough or too soft. 2) Poor lubrication 3) High pressure and much dust |
1) Take care of the surface properly. 2) Improve lubrication. 3) Select a proper rubber material. 4) Prevent dust from getting inside. |
| Ozone crack |
Multiple small gaps in the stressed direction and vertical direction.
|
Rubber dual joint is attacked by ozone to disconnect rubber. |
1) Change to an ozone-resistive rubber material. 2) Protect the surface. |
| Ubble(blister) |
Cracks on the surface. Some of them swells.
|
High pressure gas gets inside rubber to make it swell and damages rubber (after being released). |
1) Lower pressure slowly. 2) Use hard rubber, high modulus rubber. 3) Make blister-resistive formulation. |
| Skewness |
Skewness-caused damage on o-ring cross-section
|
1) O-ring is fixed on one side and skewed on the other side to be crooked. 2) Skewed loading 3) Uneven lubrication |
1) Improve lubrication. 2) Narrow gap. |
| Damage by poor installation |
Seal is partially cut. Part of seal sticks out of groove and pressed tightly.
|
1) Sharp edge on the other side or insufficient molding 2) Load diameter seal is small. Piston diameter seal is large. |
1) Mold sufficiently and remove sharp edge. 2) Adjust the seal size to groove size. |
| Abnormal abrasion in mark |
Large abrasion in marks.
|
Mark works as a foreign substance to wear out its surrounding area. |
1) Remove mark. 2) Change to color o-ring. |
