To ensure the perfect seal, a long-lasting seal that you can trust to prevent fluids and gases from escaping…. not any type of o ring will do.
There is a lot of consideration that must go into choosing the right o ring for the application for which it is intended.
For example, material type is significant, as each material will have advantages and disadvantages, making it suitable for only certain environments.
If you’re looking to buy O-rings and have questions or require further information on which type of o ring would be most suitable, speak to a member of the SSP team today on 01535 274 776, we’re happy to help.
What is an o ring?
O rings are designed to ultimately prevent leaks from occurring. O rings are available in various shapes and sizes and are designed to meet specific application requirements.
Working with the right o ring helps to keep applications operating smoothly.
Designed to sit within the groove and be compressed between two mating parts to form a tight seal, o rings are used in all industries across a range of applications.
Cost-effective and easy to install and maintain, o rings may be small, but they perform a vital role.
O ring for hydraulic fluid
O rings are ideal for hydraulic applications as they can provide a tight seal in varying temperature, pressure, and tolerance situations.
They’re also lightweight, require little space, and can be reusable depending on material choice.
Available in various shapes and sizes, in hydraulics, o rings seal the connections as they are positioned and held in place by the hydraulic pressure – preventing leaks and stopping contaminants from entering the hydraulic system.
Things to consider when choosing the right o ring for your application
Measurements – size matters with o rings, and as such, you will need to take into account the inside and outside diameter of the o ring as well as the cross-section. Diameters can vary significantly, and this must be built into decision-making as some space will be required to account for swelling and thermal expansion.
Note: O rings should not be stretched more than 5% because this can lead to the cross-section of the o ring flattening.
You must choose the most appropriate cross section to avoid extrusion and tearing and to ensure the perfect seal.
O-ring material for hydraulic fluid
There are various types of materials which o rings can be manufactured from; these include:
Nitrile (Buna N) is the most common material for o rings and is often paired with quick-acting couplings. An all-around great seal with excellent resistance to hydraulic fluids, Nitrile o rings perform best in temperatures ranging from 45 to 250 degrees Fahrenheit. These o-rings are predominantly found in oil, gas, and water applications. Note: Nitrile is not good when faced with ozone or sunlight but is resistant to compression, tear, and abrasion. NBR is the most common choice in hydraulic applications.
EPDM is a material best suited to the medical industry and automotive sector (within waste and water systems), as this type of o ring is resistant to most chemicals, heat, water, and steam and can withstand harsh environmental conditions.
FFKM – this type of metal ring gasket is not only strong but incredibly dependable. Offering users a long lifespan, the material FFKM is resistant to extreme temperatures, pressure variances, and a range of chemicals.
Fluorocarbon (Viton) – o rings manufactured in this material will be used in applications that face extreme temperatures and chemicals. Resistant to ozone, oxygen, and oils, this material is a suitable O-ring material for hydraulic fluid. In addition, increasing the fluorine content in FKM will also increase the o ring resistance to chemicals.
Silicone – odourless, non-toxic, and suitable in temperature ranges from 70 to 400 degrees Fahrenheit, this o ring type is most suitable for medical devices, food storage products, electronics, and specific automotive applications.
VMQ – resistant to ozone and weather. This is a flexible material for o rings; however, it has low tensile strength and is susceptible to wear. It is not usually a good material of choice as a hydraulic o ring.
O ring suppliers UK
When looking for an o ring for your application, it’s essential that you choose the right one.
You need to be aware of the pressure and operating temperature range that the o ring will be subject to, as the sealing capability of the o ring can be compromised if the o ring is exposed to conditions beyond what it can withstand.
For example, if the pressure is too high, you may experience some extrusion of the o ring and lose material through wear, leading to seal failure.
To combat these challenges, a backup ring that fits between the o ring and the extrusion gap may be used.
O rings are a very small part of a much larger hydraulic system; however, they are also a part that is critical to overall performance, so choosing the right one is critical.
If you’re unsure or have any questions, call us at 01535 274 776 or email your requirements to sales@specialistsealingproducts.co.uk.
