Back-up Rings
A Back-up ring is a rigid ring that holds an elastomeric seal to its designed shape, and holds it in its correct position. Back-up rings are not seals themselves, but are commonly used with O-rings, lip seals, and as reciprocating shaft seals. They prevent those seals from extruding through spaces while under pressure. Often times, it is best to use two Back-up rings installed above and below the sealing ring for extra protection.
Back-up rings are of either solid or spiral (overlapping and coiled) construction. The spiral contruction allows the overlapping rings to produce many different contact levels, thus providing extra support.
Techno Ad offers Back-up rings in a wide array of sizes, in various properties (hardness, compression-set, etc.), and tolerances in all kinds of elastomers.
Common Uses:
Back-up rings are found in a wide range of industries, including:
- Hydraulic cylinders
- High-pressure hydraulic systems
- High-pressure valves
Standards:
Techno Ad offers Back-up rings in all standard AS568 and ISO 3601 sizes, and many additional non-standard sizes.
Special tooling can be manufactured to produce exact sizes where such accuracy is required.
Techno Ad – Explore The Possibilities
Techno Ad offers Back-up rings in all standard AS568 and ISO 3601 sizes, and many additional non-standard sizes. We also offer a large selection of PTFE Back-up rings including solid, spiral, and split types.
Small minimum order quantities (MOQ) can be processed for in-stock Back-up rings.
Special tooling can be manufactured to produce exact sizes where such accuracy is required.
Frequently Asked Questions About Back-up Rings
What is a Back-up Ring and what is it used for?
A Back-up Ring is a rigid support element used alongside O-Rings or other seals to prevent extrusion under high pressure. At Techno Ad, we supply high-quality Back-up Rings that enhance the sealing system’s integrity, extending the life of O-Rings especially in demanding pressure applications.
When is it necessary to use a Back-up Ring?
Back-up Rings are critical when:
High pressures exceed the extrusion resistance of the sealing material.
Large gaps exist between mating components.
Pressure spikes or pulsing loads are present.
Soft seal materials are used that might deform under load.
Our experts at Techno Ad will recommend Back-up Rings whenever they can significantly increase sealing reliability and performance.
What materials are available for Back-up Rings?
Techno Ad offers Back-up Rings in a variety of materials to match different operating environments, including:
PTFE (Teflon®) – for chemical resistance and wide temperature ranges.
NBR and FKM (Viton®) elastomers – when compatibility with the primary seal material is essential.
Nylon and PEEK – for extreme mechanical loads and high-pressure systems.
We select materials based on pressure, media, temperature, and dynamic/static application needs.
Are there different types of Back-up Rings?
Yes. At Techno Ad, we provide:
Contoured (profiled) Back-up Rings – designed for better fit and lower friction.
Solid (un-split) Back-up Rings – ideal for smaller sizes and static applications.
Split and spiral Back-up Rings – easier to install, especially in field repairs or larger assemblies.
We assist our clients in choosing the optimal design for each application.
Can a Back-up Ring be retrofitted into an existing system?
Often, yes. Many sealing failures caused by extrusion can be corrected by adding a properly sized Back-up Ring without requiring major system redesign. At Techno Ad, we offer retrofitting advice and custom manufacturing to ensure seamless integration into your existing assemblies.
Do Back-up Rings require special groove designs?
In most cases, a standard O-Ring groove can accommodate a Back-up Ring with minor modifications. However, for best performance — especially in high-pressure dynamic applications — groove dimensions might need adjustment. Techno Ad provides full engineering support to optimize groove design for maximum sealing efficiency.
In which industries are Back-up Rings most commonly used?
Back-up Rings are essential in industries where high pressure and reliability are critical:
Hydraulic and pneumatic systems
Oil & gas exploration and production
Aerospace and defense
Heavy machinery and equipment manufacturing
Techno Ad’s Back-up Rings are designed to meet the stringent demands of these sectors and more.
Can Techno Ad provide custom Back-up Rings?
Absolutely. We specialize in custom Back-up Rings for non-standard sizes, unique groove configurations, and specialized materials. Whether for prototype development, high-volume production, or replacement of obsolete parts, Techno Ad is ready to deliver tailored solutions.