BS 5106:1988

This standard BS 5106:1988 Specification for dimensions of spiral anti-extrusion back-up rings and their housings is classified in these ICS categories:

• 21.140 Seals, glands

This British Standard specifies the design and dimensions of a range of spiral anti-extrusion back-up rings that prevent “O”-rings, which are manufactured in accordance with BS 4518, from extruding under pressure or where extrusion clearances are in excess of those specified in BS 4518. These spiral back-up rings are particularly suitable for use in hydraulic diametral sealing applications where the pressures exceed 100 bar¹⁾ and are generally less than 200 bar.

This standard also specifies the shape and dimensions of housing grooves to accommodate one or two spiral back-up rings and their associated “O”-ring.

The range of spiral back-up rings specified in this standard is intended for use with “O”-rings selected from BS 4518.

Appendix A provides guidance for the assembly of spiral back-up rings.

NOTE The titles of the publications referred to in this standard are listed on the inside back cover.

Design and dimensions of a range of rings which prevent O-rings manufactured to BS 4518 from extruding under pressure.