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Virgin PTFE Union Seal (Solid & Split) for High-Pressure Anti-Extrusion

In the complex world of well stimulation and flowback, fluids are rarely pure. They are cocktails of acids, solvents, corrosion inhibitors, and hydrocarbons. Standard NBR seals disintegrate in these mixtures, and HNBR has limits.

Technical Specifications

  • Working Pressure Ratings: 1,000 PSI to 22,500 PSI (depending on union rating)
  • Durometer: 80-95 Shore A

Applications

  • Hydraulic Fracking: High-pressure sand and proppant injection lines.
  • Flowback Operations: Managing post-frac fluids and gases.
  • Choke & Kill Manifolds: Safety-critical well control connections.
  • Mud Lines: Circulating drilling mud systems.
  • Acidizing & Cementing: Handling abrasive cement slurries and acid fluids.

Virgin PTFE Union Seal (Solid & Split) for High-Pressure Anti-Extrusion

1. Executive Summary: The Backbone of High-Pressure Sealing

In hydraulic and downhole systems exceeding 1,500 PSI, the O-ring is the primary seal, but the Backup Ring is the hero that keeps it alive.

Our Virgin PTFE Backup Rings are engineered to prevent the single most common cause of high-pressure seal failure: Gap Extrusion. As system pressure

increases, the elastomeric O-ring tends to flow like a liquid into the clearance gap between mating parts. Without support, the O-ring is “nibbled” away, leading to

catastrophic blowout. Our PTFE Backup Rings provide a hard, lubricious barrier that closes this gap, extending the pressure rating of standard O-rings to 5,000+

PSI.

2. Technical Deep Dive: Solid vs. Split Design

We offer two distinct configurations to suit your installation requirements:

Type A: Solid (Uncut) Backup Rings

  • Design: A continuous 360° ring with no cuts.

  • Performance: Offers the absolute highest extrusion resistance because there is no seam for the rubber to bite into.

  • Installation: Requires an open groove or a two-piece gland design (e.g., a removable piston head). It cannot be stretched over a rod.

  • Ideal For: OEM assembly of hydraulic cylinders and valve stems.

Type B: Split (Scarf Cut / Spiral) Backup Rings

  • Design: Features a precision angled cut (Scarf Cut) or a spiral geometry.

  • Performance: The angled cut overlaps when installed, minimizing the gap effect.

  • Installation: Can be twisted and stretched to fit into closed grooves. Ideal for field maintenance and MRO where disassembling the entire gland is impossible.

  • Ideal For: Field repair kits, internal bore grooves.

3. Material Science: Why Virgin PTFE?

  • Cold Flow (Creep): While usually a disadvantage, PTFE’s tendency to “cold flow” under load is a benefit here. Under high pressure, the backup ring deforms slightly to perfectly fill the extrusion gap, creating a zero-clearance barrier.

  • Low Friction: Virgin PTFE has one of the lowest coefficients of friction of any solid material. It does not abrade the O-ring or the metal shaft, ensuring smooth dynamic operation.

4. Detailed Specifications

Technical Parameter Specification
Material Virgin PTFE (Polytetrafluoroethylene)
Grade Unfilled, High Purity
Color White
Standard Compliance MS28774 (Teflon Backup), MS27595
Configurations Solid (T1), Split (T2), Spiral (T3)
Temperature Range -328°F to +500°F (-200°C to +260°C)
Compatible Media Universal (Inert to all Oil & Gas fluids)
Pressure Rating Up to 5,000 PSI (Virgin) / 10,000 PSI (Glass Filled option)

5. Application Guidelines

  • Single Backup: Place on the low-pressure side of the O-ring.

  • Double Backup: For reciprocating cylinders or systems with bi-directional pressure, install one backup ring on EACH side of the O-ring.