When any piece of equipment fails it can be annoying at best – but when your o-ring seal fails, it can be catastrophic. Here are seven tips you can use to help prevent o-ring failures.
Spiral failure typically occurs on long stroke hydraulic piston seals and rod seals. This usually occurs when the o-ring twists and gets caught, resulting in deep spiral cuts.
Prevention: regular lubrication of the o-ring will prevent the twisting that causes spiral failure.
Chemical degradation occurs when the chemicals in use are not compatible with the materials the o-ring is made from. Chemical degradation appears as hardening, cracking, discoloration, and/or blistering of the o-ring.
Prevention: to prevent chemical degradation, choose o-rings that are compatible with the chemicals that the o-ring will come into contact with.
Thermal degradation is less common and is likely a result of use in an environment that the o-ring is not rated for. Signs of thermal degradation are deformation and radial cracking.
Prevention: choose o-rings that are rated for use within your specific environment and operating range.
When the O-ring appears to be flattening out at the cross section you can assume that the failure is attributed to compression set. This usually happens when the o-ring has been exposed to temperatures or chemicals that are outside of the range for the seal.
Prevention: Make sure that the o-ring is rated for use within your specific equipment temperature range and chemical exposure.
User error is a very common reason for o-ring failure. When an o-ring is installed incorrectly it can result in gashes, nicks, and cuts in the seal.
Prevention: Make sure to follow the installation instructions closely. Frequently lubricating the seal is also a good way to ensure that the seal was installed correctly and prevent cuts and other damage.
Failure due to outgassing can be hard to spot as it typically presents as a decrease in the cross section. Outgassing failures can be the result of improperly cured seals or high vacuum levels.
Prevention: ensure that all seals are properly cured. This will minimize the effects of outgassing.
One of the most important things you can do to prevent O-ring failures is to properly maintain and care for them. This means following this maintenance routine:
- Regular inspection for signs of failure, wear and tear.
- Regular lubrication especially on seals that are opened and closed frequently. If the seal doesn’t feel wet or slippery, it needs to be lubricated.
- Regular cleaning with a soft brush or compressed air is another good way to prevent damage from abrasion and dust.
Prevention: when caring for an o-ring seal, make sure you refrain from poking and prying at the seal. This can create damage where there wasn’t any, to begin with. You’ll also want to refrain from introducing harsh chemicals to the seal when cleaning it or working on other parts of the equipment.