Most pipeline failures start on the inside
When a buried pipeline corrodes, the public usually blames the soil. The truth is harder to swallow — in most upstream and water-network failures we've seen, the real damage was internal, driven by H₂S, CO₂, brine, low-pH water or product contamination. External 3LPE only protects half the picture.
Our internal lining service applies a smooth, chemically inert epoxy film to the inside surface of pipes from 4-inch up to 60-inch diameter, with full-length internal-camera inspection on every piece we ship.
Two problems, one coating
Every internal epoxy lining we deliver is doing two jobs at once.
Corrosion isolation. The epoxy film completely separates the steel from whatever the pipe is carrying — produced water, raw seawater, sour gas, brine, fire-water, sewage. Even at trace H₂S/CO₂ levels that would slowly eat bare steel, the lining holds the line for 25+ years.
Flow improvement. Internal absolute roughness drops from ~50 µm (bare steel) to ~5 µm (epoxy-lined). Friction factor drops by 50% or more. For a long pipeline, that translates directly into pumping kWh saved or extra throughput at the same head.
Service applications we cover
- Potable water supply pipelines (NSF/AWWA compliant, no metallic taste)
- Crude oil and multiphase flowlines — reduces wax adherence, protects from sour service
- Natural gas transmission per API RP 5L2, improving throughput
- Firewater mains and ring networks
- Wastewater and sewage networks
- Refinery process piping for hydrocarbons, brines, amines
- Sea-water service lines for coastal industry and desalination plants
Performance figures
| Parameter | Value |
|---|---|
| Pipe diameter served | 4" to 60" (100-1500 mm) |
| Lining thickness | 250-600 µm (project-spec dependent) |
| Maximum service temperature | 95 °C standard, 150 °C high-temperature grade |
| pH tolerance | 3 to 12 |
| Pull-off adhesion | ≥ 10 MPa |
| Holiday test voltage | 4 V/µm DC |
What goes into the lining
We use two-component, 100%-solids (solvent-free) liquid epoxies — bisphenol-A or novolac base resin, polyamide/polyamine hardener, mix ratio either 4:1 or 2:1 by volume, 30-40 minute pot life at 25 °C. For potable water lines we shift to NSF/ANSI 61-certified formulations with no taste-or-odour transfer.
Standards on every project
- AWWA C210 — liquid epoxy lining of steel water pipes
- API RP 5L2 — internal flow-coating of natural gas pipelines
- ISO 15741 — friction-reducing coatings
- NSF/ANSI 61 — drinking-water contact
- NACE SP0394 — offshore internal coatings
Our application process
The line spins. We blast. We line. We inspect every metre.
- Hydroblast or chemical wash to remove mill scale, oils and salts
- Internal abrasive blast to Sa 2½, controlled anchor profile
- Vacuum dust removal with low-dew-point air purge
- Spray application — airless internal spray (long-lance) or rotating-disk
- Cure — IR-induction-accelerated or ambient (24-48 h)
- Full-length internal camera inspection
- Holiday detection at 4 V/µm
- DFT readings at 5 points per metre
Frequently asked
Can you line existing pipelines that are already in service? Yes — for rehabilitation projects we deploy cured-in-place epoxy methods. Send us the line size, length and current condition.
Is internal lining safe for drinking water? Yes when we use the NSF/ANSI 61-certified formulations. We carry the certification documentation for every project.
Does the lining make the pipe smaller? Marginally — 250-600 µm is added internally. For a 12" pipe that's 0.4-1.0% of the inner diameter. The friction-factor improvement more than compensates.
