16 Nov

As we have looked at before, a failure in hydraulic cylinders is quite often related to a seal failure. Although the price of a seal is not particularly high, domino effects can make this a very expensive occurrence. The financial costs of loss of production, engineer downtime and / or calling in engineers can soon add up. It’s for these reasons that it’s important to look at what is causing the failure of the seal first.

The key issues behind seal failure are:

Bad installation of seal. When the seal is installed, the following facts need to be considered as this is something that can easily go awry:

·         Is the equipment and the room clean enough to insert the seal?

·         Protect the seal from cuts or any damage that may prevent it from working at its optimum performance.

·         Lubrication needs to be correct

·         The seal gland should not be overtightened.

·         The seal must be placed the right side up.

Contamination of the hydraulic system.

Another primary cause of failure of hydraulic seals.  Dirt, mud, dust or grit or even internal contamination through metal chips circulating can have a devastating impact on hydraulic seals. Once hydraulic fluid starts to breakdown it can turn to sludge. Another entry point for contamination is the rod retraction cycle. This is why it’s important to install a rod wiper and why the fluid system needs to be well filtered.

Incorrect material. Seals manufactured with unsuitable materials can lead to chemical breakdown. This can occur due to the changing of hydraulic fluid also. Watch for discolouration of your seal to identify when it’s undergoing chemical attack.

Degradation from heat. Once you see the seal change colour and go hard or brittle then there could be heat degradation going on. This can lead to loss of seal. It could be that you need to change the material of the seal, or even increase lubrication.

Summary. Sometimes seals fail because they aren’t the right size or the conditions for them are not optimal. If you cannot change the conditions, at least ensure that you have the right size seal, made from quality material and you should see some improved results.