Static Spiral Multi Turn Rubber Backup Rings 55 Shore A

PTFE Backup Rings — Pressure Reversal and Support Placement

PTFE backup rings support the O-ring at the extrusion clearance. For a gland exposed to pressure from either direction, specify the pressure sequence and the space available on each side of the primary seal.

Review steady pressure, transient peaks, temperature and clearance under load when selecting a PTFE support ring. Fluid compatibility depends on the selected PTFE grade and any fillers; a backup ring alone does not establish the pressure or temperature rating of the assembly.

(PTFE) Backup Rings
Virgin PTFE: legacy hardness reference 55 Shore D; confirm the selected grade and test method.

Construction options include solid (uncut), single-turn scarf-cut and spiral multiturn PTFE rings. Specify the required construction and installation route on the drawing; these options are not interchangeable solely by nominal size.

Material range:

Virgin PTFE is an unfilled material option; specify deformation and support requirements for the operating gland.

Filled PTFE options require the filler type, content and grade data. Review mating-surface compatibility and deformation behavior for the intended duty.

For a replacement or new gland, provide the O-ring size reference, backup-ring inner and outer diameters, axial thickness and groove drawing. AS568 identifies O-ring sizes; confirm the support-ring dimensions separately.

For one-way pressure, the backup ring supports the O-ring on the low-pressure side adjacent to the extrusion gap. For reversing pressure, evaluate support on both sides and confirm that the groove accommodates the complete seal stack.

Extruded or nibbled O-ring material can indicate inadequate support at a loaded clearance. Record the damaged side, pressure direction, temperature and operating clearance before choosing the replacement arrangement.

Compare clearance control, O-ring compound and hardness, and backup-ring geometry together. Adding a second support ring changes groove occupancy and installation requirements; retain the specified O-ring squeeze and allowance for fluid-related dimensional changes.

State whether pressure reversal is normal operation, a transient event or a maintenance condition. Include the maximum differential pressure in each direction and identify the support-ring position on the assembly drawing. Do not select two rings merely because the pressure direction is unknown.

NBR and FKM rubber backup rings are separate material options. Specify rubber hardness in Shore A and PTFE hardness in the applicable scale; hardness values are not interchangeable between these materials.

For contoured support rings, provide the section profile, mating O-ring dimensions, groove width and permitted clearance. Confirm the profile and material before ordering.

We Shanghai Qinuo Industry Main Products List:

Rubber O rings:

1) Standard O-Rings

Sizes: provide 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.

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

Specify the 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

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