Gaskets also age
We need to differentiate between the time for which a gasket can or should remain in storage and its time of use, or in other words, its passive shelf life and active service life.
The service life of O-rings is governed by international aerospace regulation SAE AS5316, which defines all storage and service life conditions for elastomer products:
| Material | Service life |
| FKM | Unlimited |
| FVMQ | Unlimited |
| HNBR | 15 years |
| NBR | 15 years |
| FFKM | Unlimited |
| PTFE | Unlimited |
| VMQ | Unlimited |
We should not forget, however, that the information in this table is not binding. This information should be used simply as a basis on which to establish the requirements for the service life of gaskets, which will depend on the conditions to which they are subjected.
To ensure the longest possible service life of gaskets without them losing any performance with regard to what they are intended for (sealing properties), they must be stored properly, installed carefully and the conditions to which they are exposed must be known in order to conduct replacement or maintenance work when required.
The efficacy and duration of the sealing effect of O-rings are linked to the maintenance of their chemical and physical characteristics.
Tips for proper storage
Following a few basic storage tips will enable you to ensure your gaskets have a long service life.
- They should be stored at a temperature of between 15 °C and 38 °C.
- Relative humidity should be less than 75%.
- Gaskets should not be exposed to direct sunlight.
- They should not be exposed to sources of ionising radiation.
- They must not feature any kind of deformation and they must be tension-free.
Tips for installation
If you assemble a gasket incorrectly, this could cause superficial scratches that will undermine its sealing capacity and cause the mix to age prematurely.
The replacement of any gasket (in poor condition) entails shutting down the facility and often complex maintenance activity that needs to be scheduled in order to mitigate the economic impact thereof.
The integrity of a gasket may be compromised in the assembly or installation phase, hence the following should be taken into account:
- Avoid superficial damage: for which we recommend the use of lubricants or stretching the ring in order to widen the inner diameter.
- Avoid twisting the O-ring section: for which we recommend the use of Quad-Rings and their four support points, which are ideal for hydraulic, pneumatic and mechanical applications.
Depending on whether the installation is radial or axial, we will select a gasket with an inner diameter equal to or less than the diameter of the part to be sealed.
Check out our installation tips.
Once gaskets are in place, it is almost impossible to define their service life, as this will depend on all the factors involved: time of use, friction, temperature, fluids…, however proper installation and monitoring while they are active are important.