• October 22. 2021

The back up ring, also called anti extrusion ring, is aptly named as they do just that: they back-up an O-ring. The purpose of using the backup ring is to prevent the O-ring from extruding into the sealing gap under the system pressure. The structure of the increased back up ring will bear much higher pressure than using the O-ring alone. The profile shape of the back up ring is usually rectangula...

• June 18. 2025

EWT series Hammer Union Seals are static seals, which are used in hammer union-style pipe connections to establish flow lines and prevent leakage. JST provides a number of compounds compatible with mud, crude oil and chemicals with acid or H2S. JST offers two lines of hammer union seals, one from elastomer, another one from elastomer reinforced with anti extrusion ring which is normally used for h...