Dynamic PTFE Flat Backup Rings For Hydraulic Fluids

PTFE Backup Rings — Dynamic Gland and Operating Clearance Review

PTFE backup rings provide extrusion support for the primary O-ring. For a reciprocating or moving gland, specify the motion type, stroke, speed and duty cycle together with the seal-stack geometry. Dynamic suitability requires review of the complete assembly.

Provide normal and peak pressure, fluid formulation, temperature and the maximum clearance under operating load. PTFE grade, fillers and support geometry must suit those conditions. A general material description does not establish wear life, friction or a pressure rating for a moving seal.

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

Solid uncut, scarf-cut single-turn and spiral multiturn constructions require different installation routes and joint details. Specify the construction on the drawing and check its fit through the full motion range.

Material range:

Virgin PTFE is an unfilled option. Review deformation and dimensional stability for the pressure, temperature and duty cycle.

For filled PTFE, specify filler type, content and grade data. Review the mating-surface requirements and suitability for the intended motion.

For a dynamic-gland enquiry, provide the O-ring size, backup-ring ID, OD and axial thickness, groove dimensions and motion details. An AS568 O-ring reference alone does not define the support-ring geometry.

Define the operating extrusion gap with tolerances, eccentricity and deflection considered. A nominal assembly clearance may not represent the maximum gap reached during service.

Nibbled O-ring edges or a deformed support ring can prompt a review of clearance, pressure peaks and seal placement. Record where damage occurs and whether it changes with stroke direction before selecting a replacement.

Review the complete seal stack, including O-ring compound and squeeze, support-ring thickness, groove occupancy, lubrication and surface finish. Do not assume that adding a support ring automatically resolves friction, leakage or wear in a moving gland.

For one-way pressure, position support adjacent to the extrusion gap on the low-pressure side. Reversing-pressure arrangements require review of support on both sides and enough groove space for the specified stack.

NBR and FKM rubber backup rings are separate alternatives requiring compound and Shore A hardness data. Their dynamic suitability must be reviewed independently from PTFE.

For contoured support rings, include the profile drawing, mating O-ring and motion envelope. Specify the approved geometry and material before ordering.

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.

Provide samples or drawings with critical dimensions and tolerances for quotation.

Specify shape, color and hardness requirements 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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