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Why Should You Invest in Quality Seals?

While industrial seals might seem like something you could save a little money on, this is one part that we don’t recommend cutting costs on. A quality seal will offer many benefits to your business and operations, so it’s worth taking the time to find a solution...

All you need to know about Neoprene O rings

Popular in the refrigeration industry, neoprene o rings are also growing in popularity across a wide range of other sectors due to their incredible resistance to hazardous materials. Also known as chloroquine o rings, these o rings provide excellent resistance to...

Why all sealants are not the same

It's important to understand just how critical it is to use the correct type of sealant. It's especially the case when working with heavy machinery or any industrial situation. You don't want to have to worry about whether your sealing products are working correctly...

How to understand O-rings and their design

O-Rings are a critical component for the proper sealing of specific pipes. They have to sit within a specified groove, which can vary based on the hardware used. That's why it's important to note the various types of o-ring groove design to understand better what kind...

The importance of gasket thickness

Choosing the right gasket material for specific applications is vital. However, gasket thickness is also a feature that must not be overlooked in the decision-making process. Choosing the right gasket thickness can help when you’re experiencing challenges with...

How Temperature Impacts Gasket Performance

When using a spiral wound gasket, there are many things you need to keep in mind. The most common issue we hear people discuss regarding gasket performance issues at high temperatures. If you are using a gasket for the first time at a new temperature and notice it...

How Thick Should Gasket Paper Be?

When creating gaskets, one of the most common questions we receive is regarding gasket paper thickness. You’ll find there are various options on the market, which come in different sizes and thicknesses. Today we’re going to discover what gasket paper is and how you...

O-Rings for the Beer Industry

O-rings offer a wide range of applications, and many people aren’t aware of just how versatile an o-ring can be. When working with o-ring suppliers in the UK, you’ll soon find out that we supply these to a range of businesses, including to breweries. Today we’re going...

Gasket Safety

Gaskets and seals are vital components for applications requiring a solid seal, helping prevent leaks and stop gases and other chemicals from escaping.  However, over time, and due to the fluctuating temperatures, compression sets, and exposure to chemicals, seals do...

Is fluorosilicone rubber o rings a sustainable choice?

Fluorosilicone rubber, also known as FVQM or MFQ, contains 23-28% fluorine and has nearly the same physical and mechanical properties as standard silicone rubber as matches on par with their flexibility at low temperatures.  However, due to its fluorine...

BACK-UP RINGS

Also referred to as anti-extrusion rings, these are not actual seals themselves but are used in conjunction with ‘O’ Rings and are installed to prevent the extrusion of an elastomeric ‘O’ Ring in its housing groove under certain operating conditions. They can be used in all applications but primarily are used when higher pressures or pressure spikes, higher temperatures and / or larger extrusion gaps form part of the operating conditions. 

They are normally recommended for applications where; 

  • Fluid media pressure exceeds 10 MPa 
  • ‘O’ Rings of low strength elastomers are used 
  • Adverse mechanical conditions prevail 

Back-up Rings

Materials available

  • Virgin PTFE 
  • Filled PTFE – Fillers are sometimes added to the Virgin PTFE to improve some of its basic properties and characteristics, such as, enhanced compressive strength and thermal conductivity, reduced thermal expansion and reduced wear 
  • PEEK™ (from Victrex plc) 

This range of materials, the chemical resistance of which is almost universal, with the exception of molten alkali metals, fluorine gas and elemental fluorine, making them the ideal material choice for ‘O’ Ring Back-Up Rings. 

There are three main manufactured styles of Back-Up Rings 

Spiral Wound – A spiral of two turns is the most commonly used type of construction. This method of production allows the back-up ring to be easily opened to enable easy installation over a shaft and it also ensures the ‘O’ Ring is supported around its entire diameter. 

Solid – Generally used on very small diameters but can be difficult to install 

Endless Split  Single turn can also be supplied as an endless configuration to ensure good support. These can also be scarf split if required although we do not generally recommend this as extrusion can occur at the split 

Alternative Material Options 

Nitrile or Viton Back-Up rings are also available and have the following characteristics 

  • Molded in one-piece contoured design which enables the ‘O’ Ring to keep its shape under high pressure 
  • Can be stretched easily into place 
  • Do not cause the localised wear on ‘O’ Rings  

 

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