Tech Bulletin Back-Up Ring MS28774 Scarf Cut Sizing Guide

Backup ringsĀ provide extrusion resistance, preventing o-ring and seal damage when subjected to high pressures, temperatures, and larger extrusion gaps.

PTFE back-up rings may be used with most elastomeric O-ring seals. For installation, PTFE back-up rings are supplied either scarf or spiral cut.

This Back-Up Ring guide follows the MS28774 Scarf Cut dimensions and will discuss the dash number, Inner Diameter (ID), tolerances, thicknesses, and gap.