As568 Rubber Contoured PTFE Backup Rings Extrusion Resistance

As568 Rubber Contoured PTFE Backup Rings 90 Shore A

In a sealing application, backup rings provide added extrusion resistance and prevent damage to o-rings and seals when subjected to high pressures, larger extrusion gaps, and/or high temperatures.

Extrusion failure is one of the most common types of o-ring failure. When the internal pressure of an application becomes too great, the o-ring will actually extrude into the clearance gap. This extrudate will quickly be nibbled away causing a loss of material, and once sufficient material is lost, seal failure will quickly follow.

There are three options to prevent this, the first of which is to reduce the clearances to lower the extrusion gap. This is obviously an expensive option, so a cheaper solution is to raise the durometer of the o-ring. Even though a higher durometer o-ring offers superior extrusion resistance, this is often not a feasible solution due to material availability, and to the fact that harder durometer materials have limited low-pressure sealing ability. The last and best option is the addition of a backup ring. A backup ring is a ring of hard, extrusion resistant material such as high-durometer Nitrile, ® (FKM), or PTFE.

A backup ring is designed to fit between the o-ring and the extrusion gap and prevent the extrusion of the o-ring. Depending upon the direction of pressure in the sealing application, you can either use one backup ring or two backup rings. If unsure, it is always best to use two backup rings per one o-ring.

Commenly all back up rings in in Nitrile 90 Durometer and FKM 90 Durometer.

We can also provide contoured backup rings in other materials by request. 

Backup rings

Shanghai Qinuo can supply all American Standard Sizes for Backup Rings, details size, please contact our staff.

(PTFE) Backup Rings (VIRGIN PTFE 55 SHORE D) also available.

We also offer a large selection of PTFE Backup Rings including; Solid (uncut), Single Turn (scarf cut), and Spiral (multiturn) PTFE Backup Rings.

We Shanghai Qinuo Industry Main Products List:

Rubber O rings:

1) Standard O-Rings

Sizes: Standard AS-568 o rings, National standard of rubber o rings Ect.

Material: Nitrile (Buna-N), Silicone, Food Grade silicone, FKM,HNBR, EPDM ect.

Color: Black, Brown, or custom color.

2) Custom rubber o rings, X rings, or kinds of seals and washers&gaskets.

We Shanghai Qinuo can exactly copy according to the samples or design drawings.

Custom shape, custom color and custom hardness all available.

Hammer union seals

Available types: Rubber Hammer union seals, rubber union seals w/brass back-up, rubber union seals w/stainless back-up.

Available Material: NBR, FKM, HNBR.

Available sizes: 1” 1.5” 2” 3” 4”.

Plug seals

Available Material: NBR, FKM, HNBR ect.

Available sizes: 1” 2” 3” ect.

Dust Seals or Swivel Dust Seals

Oil saver rubbers

Pipe wipers

Swivel Ball Plugs

Thread Protectors

Below are some pictures of our products for reference:

More Pictures of our products:

Welcome to contact us for more information.