As568 Rubber Contoured PTFE Backup Rings Extrusion Resistance

Contoured Rubber Backup Rings — 90 Shore A Material and Profile Selection

Contoured rubber backup rings support the O-ring adjacent to the extrusion clearance. For a replacement, identify the NBR or FKM compound, nominal 90 Shore A hardness and section profile together with the mating O-ring and groove drawing.

O-ring nibbling at a loaded clearance can indicate inadequate support. Record the damage location, maximum pressure, temperature and operating gap before selecting the replacement ring; hardness alone does not determine the assembly pressure rating.

Compare the contoured ring profile with the O-ring cross-section and available groove space. Include inner diameter, outer diameter, axial thickness and profile tolerances. Review the rubber compound against the fluid formulation, temperature and exposure duration.

The support ring fits on the low-pressure side next to the extrusion gap in a one-way-pressure gland. For reversing pressure, review support on both sides, groove occupancy and O-ring squeeze before specifying the arrangement.

NBR and FKM options are referenced at nominal 90 Shore A. Specify the exact compound and agreed hardness tolerance on the order; these rubber specifications do not apply to PTFE alternatives.

For another rubber material or contoured profile, provide the section drawing and application conditions for review. Confirm fit with the selected primary O-ring before ordering.

Contoured Backup Ring Dimensions

For size selection, provide the AS568 O-ring dash number or metric inner diameter and cross-section, plus the support-ring dimensions and groove drawing. The O-ring size reference alone does not define the contoured backup-ring profile.

(PTFE) Backup Rings
Virgin PTFE is a separate material option with a legacy 55 Shore D reference; confirm the grade and test method.

PTFE alternatives include solid uncut, scarf-cut single-turn and spiral multiturn constructions. Confirm their dimensions, material and installation route independently; do not substitute them for a contoured rubber ring solely by nominal size.

We Shanghai Qinuo Industry Main Products List:

Rubber O rings:

1) Standard O-Rings

Sizes: specify an AS568 dash number or metric inner diameter and cross-section.

Material options: NBR, silicone, FKM, HNBR and EPDM; food-contact requirements need compound-specific documentation.

Color: Black, Brown, or custom color.

2) Custom rubber o rings, X rings, or kinds of seals and washers&gaskets.

Send a sample or drawing with critical dimensions and tolerances for quotation.

Specify required shape, color and hardness for feasibility review.

Hammer union seals

Available types: Rubber Hammer union seals, rubber union seals w/brass back-up, rubber union seals w/stainless back-up.

Available Material: NBR, FKM, HNBR.

Available sizes: 1” 1.5” 2” 3” 4”.

Plug seals

Available Material: NBR, FKM, HNBR ect.

Available sizes: 1” 2” 3” ect.

Dust Seals or Swivel Dust Seals

Oil saver rubbers

Pipe wipers

Swivel Ball Plugs

Thread Protectors

Below are some pictures of our products for reference:

More Pictures of our products:

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