What Is Pipe Lining?
Pipe lining is an internal protective layer applied to steel pipe to prevent corrosion and erosion from the transported fluid. While external pipe coating protects against soil and environmental attack, internal lining addresses the often more aggressive corrosion from process fluids, produced water, acid gases, and abrasive slurries.
Internal lining allows the use of carbon steel pipe (lower cost, higher availability) in services that would otherwise require expensive corrosion-resistant alloys.
Lining Types
| Lining Type | Material | Temp Range | Thickness | Best For |
|---|---|---|---|---|
| Cement mortar | Portland cement | 5-50°C | 3-25 mm | Potable water, wastewater |
| Epoxy | Liquid or powder epoxy | -30°C to 90°C | 150-500 microns | Oil/gas/water pipelines |
| FBE | Fusion bonded epoxy | -40°C to 85°C | 300-500 microns | Gas pipelines (drag reduction) |
| Rubber | Natural or synthetic rubber | -20°C to 120°C | 3-12 mm | Abrasive slurries, acidic media |
| PTFE | Polytetrafluoroethylene | -200°C to 260°C | 1-3 mm | Strong acids, pharma |
| HDPE | High-density polyethylene | -40°C to 60°C | 3-10 mm | Water, mild chemicals |
| GRE/GRP | Glass-reinforced epoxy/polyester | -40°C to 110°C | 3-6 mm | Seawater, produced water |
| Polypropylene | PP sheet or spray | -10°C to 100°C | 3-8 mm | Acid, brine |
| Alloy overlay | Inconel, SS, nickel | Up to 800°C+ | 3-6 mm | High-temp, high-corrosion |
Cement Mortar Lining
The oldest and most cost-effective lining for water pipelines. Cement mortar (per AWWA C205/C602) is centrifugally applied to the pipe interior, creating a smooth, alkaline surface that passivates the steel and reduces friction. Used in:
- Potable water transmission and distribution
- Wastewater force mains
- Cooling water systems
Cement lining reduces the Hazen-Williams C-factor roughness, improving flow efficiency by 15-25% compared to unlined pipe.
Epoxy and FBE Internal Lining
Thin-film epoxy linings (150-500 microns) protect against mild corrosion and reduce friction in:
- Natural gas pipelines (FBE internal lining reduces drag and prevents internal corrosion from condensed water)
- Crude oil pipelines (prevents CO2 and H2S corrosion)
- Produced water lines
Rubber Lining
Rubber-lined pipe handles abrasive slurries and acidic fluids that would rapidly erode or corrode unlined steel. Typical thickness is 3-12 mm of natural rubber, neoprene, or butyl rubber. Applications include:
- Mining slurry pipelines
- Chemical plant acid piping (HCl, H2SO4 dilute)
- Desalination plant intake piping
- Flue gas desulfurization (FGD) slurry systems
Lining vs Coating vs Cladding
| Feature | Lining | Coating | Cladding |
|---|---|---|---|
| Location | Internal | External (or internal thin-film) | Internal (metallurgical bond) |
| Bonding | Mechanical or adhesive | Fusion bond or adhesive | Weld overlay, roll-bond, or explosion-bond |
| Material | Non-metallic or metallic | Non-metallic | Metallic (CRA alloy) |
| Thickness | 1-25 mm | 0.3-6 mm | 2-6 mm |
For a detailed comparison of clad and lined pipe, see clad vs lined pipe. For the complete overview of all protection methods, see pipe coating, lining, and cladding.
Leave a Comment
Have a question or feedback? Send us a message.