Parker CPI™ / A-LOK® Two Ferrule Tube Fittings
Engineered for Leak-Free Performance in Instrumentation, Hydrogen, and Critical Fluid Applications
Parker’s CPI™ (inch) and A-LOK® (metric) two ferrule tube fittings deliver outstanding leak-tight connections for demanding applications including hydrogen refueling, analyzers, process instrumentation, and critical gas handling. Manufactured to the highest tolerances, these fittings ensure reliability even in high-pressure and corrosive environments.
Key Features & Benefits
- Dual-system compatibility: CPI™ for imperial tube sizes and A-LOK® for metric—fully interchangeable in design and performance.
- Hydrogen-ready design: Certified under EC-79 for hydrogen use; designed to resist gas leakage and embrittlement.
- High-pressure operation: Rated up to 1378 bar (20,000 psi) depending on size and material.
- Temperature performance: Handles cryogenic and high-temp service, ranging from -425°F to +1200°F (-254°C to +649°C).
- Parker Suparcase® hardened ferrules: Increase wear resistance and eliminate galling, improving fitting longevity.
- Repeatable leak-free seal: Proven design provides gas-tight integrity with consistent reassembly and minimal torque variation.
- Superior corrosion resistance: Available in 316 Stainless Steel, Alloy 625, Monel 400, and C-276 to meet NORSOK and NACE standards.
Technical Specifications
| Attribute | Details |
| Tube Sizes (OD) | CPI™: 1/16″ to 2″ / A-LOK®: 2 mm to 50 mm |
| Materials | 316SS, 6Mo, Alloy 625, Alloy 825, Monel, Titanium, Brass, C-276 |
| Max Pressure | Up to 1378 bar / 20,000 psi (size-dependent) |
| Temp Range | -254°C to +649°C |
| Seal Type | Two-ferrule mechanical grip |
| Compliance | EC-79, ISO 19880-2, NACE MR0175/ISO 15156, ASTM, ASME, PED |
| Certifications | TÜV, ECE R110, ABS, Lloyd’s, DNV |
Why CPI™ / A-LOK® is Ideal for Hydrogen Systems
- Gas-tight sealing essential for hydrogen’s small molecule size
- No galling or seal degradation under torque or vibration
- Certified for EC-79 hydrogen service, ensuring safety in mobility, fuel cell, and gas distribution systems
- Trusted globally across hydrogen refueling, storage, and electrolyzer infrastructure
Applications
- Hydrogen refueling and storage systems
- Process instrumentation and analyzers
- Offshore and marine control systems
- Research laboratories
- Power generation & nuclear
- Oil, gas, and petrochemical plants
- Cryogenic and CNG/LNG systems