Authorized Distributor of Parker O-Rings, Parker Seals and Parker Products
Authorized Distributor of Parker O-Rings, Parker Seals and Parker Products
What is a Parbak backup ring?
A Parbak backup ring is a hard (90 durometer or greater) rubber piece that improves the pressure rating of a softer rubber seal. The seal groove width must be made wider to accommodate the backup ring. See our design recommendations for more information.
What’s the difference between a Parbak rubber backup ring and a PTFE backup ring?
PTFE backup rings come in three varieties - solid, spiral wound, and split. Solid PTFE backup rings are extremely difficult to install. Since PTFE is not resilient, the backup rings must be “reformed” after being installed in the groove to return them to their original dimensions. Spiral wound and split PTFE backup rings overcome this problem - they can be opened slightly during installation without deforming them. However, they leave a sharp edge that can damage the O-ring. Parbak rubber backup rings eliminate all of these problems. Because they are rubber, they can be stretched during installation and will snap back into position. Since they have no sharp edges, they cannot damage the seal during use. Please note that Parbak backup rings are not intended to provide a seal themselves - they provide additional support in high pressure applications.
Does Parker make custom backup rings?
Yes. Click here to Request Quote on This Product
Extrusion Chart shows the relationship between rubber hardness, clearance gap, and pressure rating.
Are there backup rings for face seal grooves?
Face seal grooves are designed to have metal-to-metal contact between the mating faces, making a backup ring unnecessary. If this is not possible in your application, contact us for engineering assistance. This problem is too complex to be solved over the internet.
Does Parker make PTFE backup rings?
We offer industrial-grade solid, scarf cut, and spiral wound PTFE backup rings from compound number Z1415.
Should I use backup rings in my application?
If the pressure rating of your current design is insufficient, using a backup ring may be the key. Parker's
Are there backup rings for 5-xxx o-rings?
We can create them as custom backup rings, but they are not available off-the-shelf. Click here to Request for Quote on This Product
What materials are Parbak backup rings made from?
Parbaks are generally made in N1444-90, a 90 durometer nitrile (NBR) rubber material specifically developed for use as a backup ring material. Backup rings are also available in N0300-90 (NBR,) E0652-90 (EPDM,) V0709-90 (FKM,) V1238-95 (high pressure FKM,) and V8588-90 (Parofluor.)
