Clad vs Lined vs Solid Alloy
Three ways to solve pipeline corrosion. One right choice for your operating conditions. Technical comparison to help engineers and procurement teams specify with confidence.
Solid CRA Alloy Pipe
The entire wall is corrosion-resistant alloy (316L, 2205, 625, etc.). Maximum corrosion resistance, maximum cost.
Metallurgically Clad Pipe
Carbon steel outer wall for strength. Thin CRA inner layer metallurgically bonded for corrosion protection. Best of both metals.
Mechanically Lined Pipe
CRA liner inserted into carbon steel pipe and held by mechanical interference. Lowest cost, lowest bonding strength.
Head-to-Head Comparison
Every dimension that matters for pipeline specification
| Dimension | Solid CRA Alloy | Metallurgically Clad | Mechanically Lined |
|---|---|---|---|
| Construction | Single-material wall | Carbon steel outer + CRA inner, metallurgically bonded | Carbon steel outer + CRA liner, mechanically fitted |
| Bonding Strength | N/A (homogeneous) | 0.2 – 16 MPa (53× API 5LD min) | 0.3 – 0.8 MPa (mechanical interference) |
| Cost vs Solid Alloy | 100% (baseline) | 30 – 50% lower | 40 – 60% lower |
| Weight | Heavy (full alloy) | Light (thin CRA layer) | Light (thin CRA liner) |
| Corrosion Resistance | Excellent | Excellent (equivalent to solid CRA) | Good (liner barrier only) |
| Pressure Rating | High | High (structural CS wall) | Moderate (liner deforms under extreme pressure) |
| Cutting | Standard | Standard (bond holds) | Requires care (end seals needed) |
| Welding | Standard CRA welding | Requires transition weld overlay | Standard (weld into liner) |
| Bending | Standard | Standard (liner stays bonded) | Limited (risk of liner buckling) |
| Max Size | Unlimited | DN15 – DN1400+ | Typically ≤ DN600 |
| Temp Range | Alloy-dependent | -20°C ~ 350°C | -20°C ~ 200°C |
| Key Standards | ASTM A312, A790, etc. | API 5LD, ASME SA-263/264/265, DNV-ST-F101 | API 5LD, DNV-OS-F201 |
Which One for Your Project?
Scenario-based recommendations from our engineering team
Oil & gas transmission, sour gas (H₂S), high pressure
Metallurgical bond withstands thermal cycling, pressure surges, and bending during installation. No risk of liner delamination.
Drinking water, fire protection, building plumbing
Mechanical lining is cost-effective for low-pressure, ambient-temperature applications. Food-grade inner surface meets GB/T 17219.
Chemical processing, chlorides, acids, thermal cycling
Aggressive media + temperature swings demand metallurgical bonding. Mechanical liners can fail under thermal expansion mismatch.
Desalination, seawater cooling, marine
Clad for high-pressure subsea or power plants. Lined acceptable for low-pressure intake lines.
Budget-constrained, moderate corrosion, static conditions
Lower cost while still achieving corrosion resistance. Ensure operating conditions stay within liner mechanical limits.
The RSP™ Difference
ZONX proprietary Right Spinning Pressure (RSP™) technology achieves metallurgical bonding forces of 0.2–16 MPa — far exceeding the API 5LD minimum of 0.3 MPa.
- Bonded at the molecular level — cut, weld, or bend without delamination
- Thin CRA layer (typically 1–3 mm) vs. full alloy wall = 30–50% cost savings
- Full traceability: every pipe serialized with bonding test report
- Lead drafter of Chinese national standard GB/T 31940-2015
Still unsure which pipe type fits your project?
Send us your operating conditions — media, temperature, pressure, and installation method. Our engineering team will review your requirements and respond during business hours.
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