Wireline Packing: PTFE-Coated High-Durability Seals
Wireline Packing features an exclusive engineered design: a resilient elastomeric core (typically HNBR or FKM) precisely molded, then overcoated with low-friction PTFE (Polytetrafluoroethylene) via dispersion impregnation or skiving. This hybrid construction delivers 50% longer service life than conventional stuffing box packings, reducing maintenance cycles from 100-200 hours to 150-300+ hours in slickline/electric line operations.
The PTFE coating (0.1-0.5 mm thick) minimizes stick-slip (friction coefficient <0.1), prevents wire galling, and enhances chemical resistance (pH 0-14), while the elastomer provides radial expansion under pressures up to 10,000 psi (69 MPa) and temperatures -20°C to 250°C.
Standard Sizes for Stuffing Box Applications
| Bore ID (inches) | Stack Height (inches) | No. of Elements | Pressure Rating (psi) | Wire Size Compatibility |
|---|---|---|---|---|
| 1-1/2 | 2.50-3.00 | 5-7 | 5,000 | 0.092-0.125″ |
| 2-1/4 | 3.25-3.75 | 6-8 | 7,500 | 0.125-0.156″ |
| 3 | 4.00-4.50 | 7-9 | 10,000 | 0.156-0.188″ |
| 4 | 5.00-5.50 | 8-10 | 7,500 | 0.188-0.219″ |
Performance Comparison
| Feature | Conventional Packing | Wireline Packing (PTFE-Coated) |
|---|---|---|
| Service Life | 100-200 hours | 150-300+ hours (+50%) |
| Friction Coefficient | 0.3-0.5 | <0.1 |
| Max Pressure (psi) | 5,000 | 10,000 |
| Temp Range (°C) | -10 to 150 | -20 to 250 |
| Shaft Speed (fpm) | 500-800 | 1,000-1,500 |
Material Specifications
| Component | Material | Key Properties | Standards Compliance |
|---|---|---|---|
| Core | HNBR/FKM elastomer | 80-90 Shore A; 300% elongation | ASTM D2000, NACE MR0175 |
| Coating | PTFE dispersion | 260°C max; zero water absorption | FDA-compliant, API 16A |
| Reinforcement | Optional Kevlar plies | Tensile >20 MPa | API Spec 6A Annex F |
This design undergoes accelerated aging tests showing <20% hardness increase after 70 hours at 150°C, ensuring consistent sealing in sour service environments.