Teflon PTFE Split Backup Ring AS568A-114 - 2806

High-Reliability PTFE Backup Ring in AS568A-114 Size

A PTFE backup ring AS568A-114 is a specialized anti-extrusion device that sits alongside a standard dash 114 O-ring to prevent it from being forced into the clearance gap between mating metal surfaces under pressure. The AS568A-114 size references a nominal inside diameter of 0.612 inches and a cross-section of 0.103 inches, a configuration found across hydraulic cylinders, pneumatic manifolds, directional valves, and chemical processing pumps.

This ring delivers one core function: it protects the 114-size O-ring from extrusion and premature failure in high-pressure, chemically aggressive, or thermally demanding service. Back-up rings prevent O-rings from extruding under pressure, and in the AS568A-114 size, that protection translates directly into longer seal life, fewer unplanned shutdowns, and reduced maintenance cost across many applications.

Why You'll Rely on the PTFE Backup Ring AS568A-114

PTFE back up rings in this size keep sealing systems running longer between overhauls and eliminate the nibbled, extruded O-ring failures that cause fluid leaks and production stops.

• Extrusion Protection for Dash 114 O Rings – Back-up rings increase the pressure capability of O-rings by filling the extrusion gap on the low-pressure side of the gland. In AS568A-114 grooves, this means the elastomer stays intact at pressures where an unsupported O-ring would fail. PTFE backup rings are used in high-pressure systems exceeding 1,500 psi, and they are essential in hydraulic cylinders experiencing pressures over 5,000 PSI.

• Chemical and Fluid Compatibility – PTFE offers outstanding chemical resistance against acids and solvents, as well as hydraulic oils, glycol-based coolants, fuels, and aggressive media encountered in process equipment. PTFE back-up rings are used in valves handling aggressive chemicals, where elastomers alone may swell or degrade.

• Temperature Stability Across a Broad Temperature Range – PTFE backup rings operate reliably from -65°F to +500°F, covering cryogenic through high-temperature duty cycles without brittleness or softening. The ability to withstand high temperatures and deep cold makes PTFE the best material for sealing applications exposed to wide operating temperature swings.

• Reduced Maintenance Interruptions – PTFE backup rings help reduce maintenance frequency due to reduced seal damage. By preventing extrusion, the O-ring retains its original cross-section and sealing function over more pressure cycles, which extends service life and cuts replacement part consumption.

• Consistent Performance in Tight Glands – PTFE is highly wear-resistant and dimensionally stable under pressure. In the AS568A-114 gland geometry, this means the backup ring holds its shape through sustained static loads and slow dynamic motion without cold-flowing out of position.

• Low Friction in Dynamic Applications – PTFE has a low coefficient of friction, reducing wear in dynamic applications such as reciprocating rods and pistons. This extremely low friction also reduces breakout force and stick-slip behavior in hydraulic and pneumatic cylinders using 114-size seals.

What Makes This AS568A-114 PTFE Backup Ring Different

Generic anti extrusion rings may approximate the right size but leave tolerance gaps that compromise sealing performance. A PTFE backup ring manufactured to AS568A-114 dimensions matches the groove geometry, the O-ring cross-section, and the clearance gap of dash 114 hardware without guesswork.

• Precision to the AS568A-114 Standard – AS568A specifies standard O-ring sizes, and the corresponding backup ring dimensions are tightly controlled. For dash 114, the backup ring ID is approximately 0.640 inch (±0.009 inch), with a radial width of about 0.086 inch (±0.003 inch) and an axial thickness of roughly 0.053 inch. These tolerances ensure the ring fills the sealing gap without interfering with O-ring squeeze.

• Virgin or Engineered PTFE Options – Virgin (unfilled) PTFE delivers the widest chemical resistance and temperature range. Glass-filled or carbon-filled PTFE compounds reduce creep and increase mechanical strength for applications where sustained high pressure or abrasive media would cause virgin PTFE to cold-flow over time. The availability of multiple compounds lets engineers match the ring to a specific application rather than accepting a one-size-fits-all material.

• Split or Solid Profiles – PTFE back-up rings come in solid, split, and spiral types. Solid back up rings provide maximum extrusion protection in new-build assemblies with open grooves. Split PTFE back-up rings feature a 45° scarf-cut for easy installation into closed glands. Spiral back up rings use overlapping coils for even pressure distribution. Each profile is available in AS568A-114 dimensions.

• Designed for Hydraulic and Pneumatic Duty – The ring's dimensions and material properties align with the pressure ranges, motion types, and fluid exposures common in hydraulic systems and pneumatic systems using 114-size O rings. They enhance sealing in pneumatic systems with pressures up to several hundred PSI and support hydraulic service well above 5,000 PSI when paired with the correct O-ring compound and groove design.

How the PTFE Backup Ring AS568A-114 Works in a Seal Assembly

The backup ring does not seal fluid on its own. The O-ring handles sealing. The PTFE ring's function is to block the path the O-ring would otherwise be forced through under differential pressure, preventing extrusion and preserving the elastomer's shape.

1. Placement in the AS568A-114 Groove – The backup ring sits on the low-pressure side of the O-ring inside the standard dash 114 gland. When pressure can reverse direction, two back up rings are installed, one on each side of the O-ring, so the elastomer is supported regardless of which way the pressure acts. This arrangement is standard for back up O rings in bidirectional circuits.

2. Loading Under Pressure – When system pressure rises, the O-ring deforms toward the clearance gap between the piston or rod and the bore wall. The PTFE ring, positioned between the O-ring and the gap, absorbs contact from the pressurized elastomer and physically blocks the extrusion path. PTFE back-up rings maintain shape under extreme pressure cycling, so the ring does not deform into the gap itself.

3. Maintaining Seal Integrity – Because the O-ring cannot be pushed into the clearance gap, it retains its circular cross-section and continues to seal. Without a backup ring, repeated pressure cycles nibble the elastomer into the gap, causing seal failure. With the PTFE ring in place, the O-ring's sealing surface stays undamaged.

4. Performance Over Time – PTFE does creep under sustained load, which means that in long-term static applications, the ring slowly conforms to the groove surfaces. This gradual conformity can actually improve gap coverage. In slow-dynamic or reciprocating 114-size assemblies, PTFE's wear resistance and low friction keep the backup ring functional for thousands of cycles before inspection or replacement is needed.

Product Details: PTFE Backup Ring AS568A-114

These are the specifications engineers need when selecting or verifying a PTFE backup ring for dash 114 hardware.

• Material: PTFE (polytetrafluoroethylene), white, commonly called Teflon. Available in virgin PTFE and filled variants (glass-filled, carbon-filled, bronze-filled) for applications requiring higher stiffness or wear resistance. PTFE is FDA compliant, ensuring safety in industrial applications where food-contact or pharmaceutical standards apply.

• Standard Size Reference: AS568A dash 114, matching the standard 114 O-ring and gland dimensions used across hydraulic, pneumatic, and process equipment.

• Backup Ring Inner Diameter: Approximately 0.640 inch (16.26 mm), ±0.009 inch (±0.23 mm).

• Backup Ring Radial Width: Approximately 0.086 inch (2.18 mm), ±0.003 inch (±0.08 mm).

• Backup Ring Axial Thickness: Approximately 0.053 inch (1.35 mm).

• Compatible O-Ring: AS568A-114; ID 0.612 inch (15.54 mm), cross-section 0.103 inch (2.62 mm).

• Profile Types: Solid (continuous ring), split ring with scarf cut (bias-cut for field installation), and spiral (overlapping coil). Stock availability varies by profile; split rings are commonly stocked in this size due to their easy installation and broad demand.

• Temperature Range: Virgin PTFE operates from approximately UP TO 392°F. Practical operating temperature in a sealing application depends on the O-ring material, the fluid, and the pressure.

• Pressure Capability: In static applications with filled PTFE, backup rings in this size can support working pressures up to approximately 250 MPa (36,250 PSI) with minimal extrusion gaps. In dynamic applications with virgin PTFE, practical limits are closer to 40 MPa (5,800 PSI). These figures depend on gap size, O-ring hardness, and motion type.

• Standards and Compliance: Sized per AS568A. Compatible with groove designs referencing SAE ARP1802C (selection and application of PTFE backup rings in fluid power systems). Procurement cross-references may include MS28774-114 (single-turn PTFE backup for dash 114) in legacy aerospace specifications.

Installation and Best Practices for AS568A-114 PTFE Backup Rings

Correct installation determines whether the PTFE backup ring delivers its full anti-extrusion capability. A mispositioned or damaged ring can accelerate the seal failure it was meant to prevent.

• Confirm Groove Dimensions – Verify that the rod or piston gland conforms to AS568A-114 dimensions before fitting the ring. The groove must have sufficient axial depth to accommodate both the O-ring and the backup ring without over-compressing the elastomer. If the groove was originally cut for an O-ring only, check that the added ring thickness does not reduce O-ring squeeze below the minimum required for sealing.

• Choose Correct Orientation – Place the backup ring on the low-pressure side of the O-ring. When pressure can act from either direction, install two back up rings, one on each side. This bidirectional arrangement is standard in reversing hydraulic cylinders and shuttle valve circuits.

• Avoid Sharp Edges – Chamfer and deburr all edges that the PTFE ring must pass during assembly. A sharp corner can shave material from the ring surface, creating debris in the gland and reducing the ring's ability to fill the extrusion gap. This step is equally important for solid, split, and spiral profiles.

• Use Suitable Assembly Tools – Non-metallic tools (nylon or PEEK pushers, for example) reduce the risk of nicking or gouging the PTFE surface during installation. Scratches on the ring face that contacts the O-ring can concentrate stress and accelerate creep.

• Verify O-Ring Compatibility – Pair the backup ring with an O-ring of the correct hardness (commonly 70 Shore A durometer for general hydraulic service) and a compound suitable for the fluid and temperature in the system. A PTFE backup ring paired with a chemically incompatible or too-soft O-ring will not prevent extrusion at the rated pressure; both components must be selected together for the sealing application.

Frequently Asked Questions About PTFE Backup Rings AS568A-114

These questions come up when engineers and maintenance teams specify or install dash 114 PTFE backup rings.

Do I always need a backup ring with an AS568A-114 O-ring? No. At low pressure (below roughly 1,500 PSI in static applications with tight clearance gaps and a 70-durometer O-ring), the elastomer alone typically resists extrusion. Backup rings become essential when pressure exceeds 1,500 PSI, when the clearance gap is wider than recommended for the O-ring hardness, or when the system handles aggressive media that softens the elastomer over time. They are essential in high-pressure sealing applications where the factors driving extrusion are present.

Can I use the same backup ring for both rod and piston glands? AS568A-114 defines the size, not the gland type. A backup ring matching dash 114 dimensions fits both rod and piston grooves of that size. The choice between solid, split, or spiral profiles depends on how the gland is assembled and whether the ring must pass over a shaft (rod gland) or fit inside a bore (piston gland).

Should I install one or two backup rings with a dash 114 O-ring? One ring is standard for unidirectional pressure. Place it on the low-pressure side. For bidirectional pressure (common in double-acting hydraulic cylinders and shuttle valves), install two back up rings, one on each side of the O-ring. The groove must be deep enough to accommodate both rings plus the O-ring without sacrificing elastomer squeeze.

How do PTFE backup rings compare to other materials in this size? Nylon backup rings cost less and resist creep better than virgin PTFE but fail in contact with many chemicals and above roughly 120°C. PEEK offers higher mechanical strength and stiffness but costs several times more than PTFE and is harder to machine in small quantity. Hard rubber (e.g., 90A durometer) is inexpensive but degrades in solvents and at high temperatures. PTFE covers the widest combination of chemical resistance, temperature range, and low friction, which is why it remains the most common backup ring material for demanding applications across industries.

Can an AS568A-114 PTFE backup ring be reused? Inspect the ring for visible deformation, surface scratches, and signs of creep (permanent thinning or widening). If the ring has maintained its original dimensions and shows no damage, reuse is physically possible. In critical service (aerospace, high-pressure hydraulic systems, chemical processing), replacing the backup ring during each overhaul is standard practice because PTFE's creep behavior can reduce extrusion resistance after prolonged service under load.

Ready to Renew Your PTFE Backup Ring in AS568A-114?

PTFE backup rings in AS568A-114 protect dash 114 O-rings from extrusion in high pressure applications, chemically aggressive environments, and systems cycling across a broad temperature range. They are the standard anti extrusion solution for 114-size grooves in hydraulic systems, pneumatic systems, chemical processing, and aerospace hardware.