The functionality and performance of an o ring depends on several factors, with one of the most significant factors being the environment in which the o ring is placed and exposed to.
At SSP, we know that every o ring is chosen to suit the application and device it is being used within, with careful selection of materials, hardness, shape, density, etc., all taken into consideration.
This level of consideration is vital. Vital because every application will be and is, different.
For example, some applications will be exposed to extreme and fluctuating temperatures. Others may be met with harsh chemicals requiring a different o-ring material.
In all cases, the chosen o ring must be suitable and continue to perform to a high standard to avoid potential leaks and contamination.
We know that you want to have high functionality and longevity in your o rings, which is why many manufacturers now take on a number of preventative steps at the beginning of their processes. Mapping out application requirements and ensuring seals are fully compatible.
With this in mind, what steps can you take to prevent environmental factors from negatively impacting your o rings?
O ring environment
Heat
When rubber o rings are exposed to incredibly high temperatures, the o ring can deteriorate quickly. Affecting the o rings strength and overall compatibility with the complete application, impacting performance and no longer providing a secure seal.
O ring material choice in high-temperature applications could include nitrile or silicone rubber.
Cold
Cold weather conditions can mean rubber o rings will lose elasticity, affecting overall compression.
O ring materials suitable for cold applications include FFKM, HNBR, and EPR.
Water
Providing a seal to prevent leaks and spillages, o rings must still be suitable for cases where they may see too much water, excess moisture, or high humidity levels. All of these can lead to the o ring swelling, changing the o ring’s physical properties.
O ring materials suitable for these environments include nitrile, Viton, or EPR.
Ozone
UV light can result in the deterioration and cracking of o ring material. As such, o rings should be kept out of direct sunlight, correctly lubricated, and the material should be fluorocarbon or EPDM.
How to combat weather exposure to o rings
Choose the right material.
O rings must be compatible with the chemicals and external factors they will be exposed to. Failure to choose the right material can result in faster wear and tear in the o ring, leading to overall failure and more severe problems.
For example, if we look at the o ring climate of cold weather and its effect on rubber o rings, we’ll see that the rubber will fast lose its elasticity, making it less flexible, prone to snapping and breaking, with the o ring often struggling to return to its natural size after compression.
Know the pressure.
Pressure does and will affect o ring performance, causing the o ring to distort and twist. This, in turn, affects the gap between the two mating surfaces.
In addition, if the wrong o ring is exposed to increasingly high pressure, the o ring will extrude from the mating surfaces leading to the seal failing, potential leaks, and the risk of contamination.
To help manage the effects of pressure, you can increase the hardness of o rings, use backup o rings, and even look to lower the pressure of the application where applicable.
Be prepared for extrusion.
It’s essential that you check that o ring material will be compatible with fluids/chemicals, as well as choosing the right size o ring for the clearance gap it is required to fill – you’d be surprised how often this is a major cause of failure.
Be aware of friction.
Continuously moving parts place additional pressure on o rings. Understanding the friction level will help determine which o ring to opt for. The wrong o ring that is unable to withstand friction can experience swelling, tearing, and complete failure.
To help, o-ring suppliers often advise opting for cross-section o-rings, carrying out regular lubrication, and potentially increasing groove width.
Understand temperature ranges.
As mentioned above, some o-rings work well in extreme heat and cold, whereas others work better at room temperature.
You need to choose the appropriate sealing material for the application, understanding all the environmental factors that will have an impact.
O ring suppliers, UK
O rings are used in dynamic and static applications; however, both will be exposed to environmental factors like those mentioned above.
You need to know what type of o-ring you not only want but that you need for your specific application.
As specialists in our field, to find out more and have your questions answered, speak to a member of our experienced team on 01535 274 776 or email your requirements to sales@specialistsealingproducts.co.uk.
