Zatkoff Seals & Packings 55551316 NBR Back-Up Ring

This is a nitrile rubber (NBR) back-up ring supplied by Zatkoff Seals & Packings under part number 55551316. Zatkoff is a stocking distributor and fabricator of sealing products, so the number on the bag is a Zatkoff item number rather than a molder's catalog size; the bag label carries a batch number and a cure date code for traceability.

A back-up ring is fitted in the gland beside an O-ring or other elastomer seal, on the low pressure side. It supports the seal and keeps it from extruding into the clearance gap between the mating parts. Zatkoff's catalog states that back-up rings extend the operating pressure range of O-rings, increase O-ring life with fewer service replacements, and improve seal performance. Zatkoff lists back-up rings in contoured continuous, solid continuous, split and spiral styles, with 90 durometer nitrile as its stock standard material.

Hydraulic and pneumatic cylinder rebuilders, valve and pump repair shops, and plant maintenance departments use back-up rings when rebuilding high pressure seal glands. Buyers should confirm the ring dimensions against the gland before ordering.

Available from King Surplus inventory in Del Rio, Texas.

• Product: Back-up ring
• Material: NBR (nitrile rubber), per label
• Part Number on Label: 55551316
• Label Batch No.: 0072742758
• Label Cure Date Code: 4012
• Country of Origin on Label: China
• Supplier on Label: Zatkoff Seals & Packings, stocking distributors and fabricators of sealing systems
• Function (Zatkoff catalog): Extends the operating pressure range of O-rings, increases O-ring life and improves seal performance
• Spec Basis: Bag label photo (ZATKOFF SEALS & PACKINGS, 55551316, DESCRIPTION: NBR BACK UP RING, BATCH NO 0072742758, CURE DATE 4012, MADE IN CHINA); Zatkoff O-Ring Backup Rings catalog section (https://www.zatkoff.com/catalog/master-catalog/backup-rings). Ring size, durometer and profile are not on the label and no published data was found for this part number.