Backup rings provide additional extrusion resistance and prevent damage to O-Rings and seals.
Backup rings can be used in all applications but primarily are added when higher pressures or pressure spikes, higher temperatures and / or larger extrusion gaps form part of the operating conditions.
Backup rings are not seals themselves, but are used in conjunction with O-rings or other seals in high-pressure applications. Backup rings are installed in the downstream side of the gland, however can be installed either side of the O-ring to give a high performance double acting seal.
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VICTREX PEEK
It is a linear, aromatic, semi-crystalline polymer widely regarded as one of the highest performing thermoplastics in the world. It provides a unique combination and range of high performance properties.
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PTFE
Being hydrophobic, non-wetting, high density and resistant to high temperatures, PTFE is an incredibly versatile material with a wide variety of applications, though it's perhaps best-known for its non-stick properties.
Detailed design and manufacture
AFT Fluorotec is a registered and approved processor of VICTREX PEEK materials. We can design and manufacture an almost limitless range of VICTREX PEEK backup rings (BURs) as well as PTFE rings.
We can manufacture to customer drawings/specifications and design backup rings to suit your specific applications.
Many materials can be used but primarily VICTREX® PEEK is used in backup rings.
Plain PEEK backup rings
- Flat-faced rectangular section rings similar to washers
- These are dimensioned to neatly fit the radial cross section of the seal groove
- Length (thickness) can be to BS or ASTM standards or specified to suit any application
Contoured PEEK backup rings
- A step up in performance over plain PEEK backup rings
- Designed with a concave or contoured face on one side and a flat face on the other
- The contoured face has a greater contact area with the O-Ring and provides better grip and support than a standard flat option.
- Length (thickness) can be to BS or ASTM standards or specified to suit any application
Positively actuated backup rings
- Automatically forced (actuated) by the system pressure both axially and radially to blank the extrusion gap
- Can be integrated into a seal design or they can be specially shaped individual items
- Often in the form of two individual rings, which work against each other to completely eliminate any gap
Backup ring - Material Selection
Whilst Virgin PEEK is the mainstay of backup ring materials, other materials can be used. For example, Acetal may be used in applications which are high pressure but do not require the chemical or temperature resistance of VICTREX PEEK.
Virgin PTFE or Glass-filled PTFE may be used where medium pressure and chemical resistance form the criteria but the temperature is not an issue.
At the other end of the scale, filled VICTREX PEEK materials such as Glass-filled VICTREX PEEK or Carbon Filled VICTREX PEEK may be used to offer increased compressive strength and extrusion resistance over Virgin PEEK.
VICTREX PEEK is inert to all common solvents and resists a wide range of organic and inorganic liquids. VICTREX PEEK has a maximum continuous working temperature of 260°C and retains its mechanical properties up to 300°C in steam or high-pressure applications.
Fluorotec can advise you on the optimal material to use for your application.
Backup Rings
Have a query about our back up rings? Get in touch.
Our team are happy to answer any questions you have about using our products and services in your next project. Fill in your details below and we'll be in touch.
PTFE O-rings are used in high pressure, static applications, and dynamic applications.
They offer:
- Sealing capabilities
- Chemical resistance
- Prevent extrusion (especially when paired with back up rings or anti extrusion rings)
- Reduce the risk of O ring extrusion
Back-up rings are made from PTFE, hard rubber materials, or similar tough polymers. PTFE back up rings are preferred for their strength, chemical resistance, and ability to handle system pressures. They are available in solid and split styles depending on your system needs.
Yes, PTFE lubricant is safe for most O-rings. It reduces friction during installation and protects the seal in the groove.
Yes, PTFE is safe to use with rubber materials. It doesn’t react and supports sealing performance when used with O-rings, back up rings, and anti extrusion rings.
PTFE O-rings work in temperatures from -200°C to +260°C This is ideal for static and high pressure applications, and aggressive environments. Their stability offers many advantages.
PTFE back up rings are a common type of anti extrusion ring. They are used to protect an unsupported O ring in a groove. The right ring improves sealing and extends seal life. Visit our page to learn more about choosing the right ring for your setup.
At AFT Fluorotec, we specialise in high-performance PTFE back up rings. Our in-house machining ensures top-quality materials like PTFE and hard rubber materials, ideal for both static and dynamic applications. This guarantees consistent quality and full customisation to match your system.
With many advantages and fast lead times, AFT is your trusted choice. Visit our page to learn more.
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