Dynamic Static Sealing Backup Rings AS568 Rubber O Rings

AS568 O-Rings and PTFE Backup Rings for Static Gland Assemblies

For a static seal, the O-ring provides sealing contact while a correctly fitted backup ring supports it at the extrusion clearance. Specify the O-ring dash size and groove drawing together; a backup ring does not replace the primary seal.

Review PTFE grade, O-ring compound, fluid composition, temperature and pressure cycles for the complete static assembly. Compatibility and pressure capability depend on these conditions and the clearance under load.

PTFE Material and Ring Construction
Virgin PTFE hardness reference: 55 Shore D; grade and test acceptance range to be confirmed.

Solid, scarf-cut and spiral rings require different installation procedures. Identify the ordered construction and check its fit within the static groove before assembly.

Material range:

Virgin PTFE: review compression and creep requirements at the specified temperature and load.

Filled PTFE: specify glass, graphite, carbon or bronze filler grade and content, with fluid and mating-surface requirements.

Send the AS568 O-ring dash number and static gland drawing with backup ring ID, OD, thickness and tolerances for quotation.

Include the groove width required for the O-ring and support ring, O-ring squeeze and the maximum operating clearance. Define the pressure direction and any pressure reversal.

Inspect seals and mating surfaces when extrusion damage is suspected. Record the clearance, pressure peaks and temperature so the replacement assembly can be reviewed against the failure conditions.

Consider seal compound, hardness, groove dimensions and backup support together. Specify the assembly access and installation route; avoid treating increased hardness or an added ring as a universal correction.

For a defined pressure direction, support the O-ring on the low-pressure side. Pressure reversal may require rings on both sides, with groove space and orientation confirmed on the drawing.

NBR or FKM 90-durometer rubber support rings are separate options requiring the compound and hardness scale. Do not apply rubber Shore A values to PTFE.

Contoured backup ring profiles require their own section drawing and material specification.

Related Rubber and Oilfield Components

Rubber O rings:

1) Standard O-Rings

Sizes: AS568 dash sizes or specified metric dimensions with tolerances.

Materials: NBR, silicone, FKM, HNBR or EPDM by specification; food-contact requirements need compound documentation.

Color: Black, Brown, or custom color.

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

Custom parts are quoted against approved drawings or samples with mating dimensions.

Specify shape, color and hardness requirements on the part drawing.

Hammer union seals

Rubber union seals with or without brass or stainless-steel backup rings; fit by assembly drawing.

Available Material: NBR, FKM, HNBR.

Nominal union sizes: 1, 1.5, 2, 3 and 4 inches; seal fit by assembly specification.

Plug seals

Available Material: NBR, FKM, HNBR ect.

Nominal sizes: 1, 2 or 3 inches; plug seal dimensions by assembly drawing.

Dust Seals or Swivel Dust Seals

Oil saver rubbers

Pipe wipers

Swivel Ball Plugs

Thread Protectors

Related product photographs for reference; confirm the ordered seal assembly by drawing:

Additional related product photographs:

For a static O-ring and backup ring enquiry, provide the dash size, groove drawing, pressure direction, fluid and temperature. Specify both material designations and quantity, then confirm sample fit and assembly inspection requirements.