Restore burst pressure to a corroded pipeline without taking it out of service
Pipelines lose wall thickness slowly. A 12 mm-wall trunkline that started life with 30 bar burst margin can drop to 15 bar after 20 years of service — still operating, but no longer at design pressure. The traditional fix is to cut out the corroded section and replace it: line shutdown, cut, weld, hydrotest, recoat, restart. Days of lost throughput, often weeks.
Composite reinforcement wraps fix the same problem in hours, on a live pipeline.
How composite reinforcement works
A multi-layer wrap of high-strength fibre (glass, carbon, or aramid) is applied around the corroded section using a structural epoxy adhesive matrix. As the resin cures, the wrap becomes a load-bearing composite shell that takes a portion of the hoop stress away from the original pipe wall. Effectively, the wrap restores (or exceeds) the original pipe's burst pressure capability — without depressurizing or replacing the line.
Where we use it
- External corrosion losses — wall-thickness reductions up to 80% of original wall
- Mechanical damage — dents, gouges, third-party damage
- Weld defects — porosity, cracks, lack of fusion (with appropriate qualification)
- Riser splash-zone repairs on offshore platforms
- Buried pipeline rehabilitation without excavating-cut-replace-recoat cycles
- Bend and tee reinforcement — composite wraps conform to complex geometries
- Tank and vessel stiffening — composite reinforcement of corroded shells
Wrap systems we supply
Glass-fibre composite (E-glass)
General-purpose, cost-effective, suitable for most pressure-pipe repairs up to 100 bar service. Good corrosion resistance, electrical insulation, ease of installation.
Carbon-fibre composite
Higher modulus, lighter weight, suited to high-pressure or stiffness-critical repairs. Used where the wrap thickness must be minimised (clearance issues, drag-sensitive offshore service).
Aramid (Kevlar) composite
Maximum impact and tear resistance. For applications where the wrap may see secondary mechanical loading (river crossings, traffic-load zones).
Pre-impregnated wrap kits
Factory-pre-impregnated fibre tape on a release liner — speeds up field application, eliminates resin-mixing on site, gives more consistent fibre/resin ratios.
Build properties (typical glass-fibre system)
| Property | Value |
|---|---|
| Layer thickness | 0.5-1.0 mm per ply |
| Number of plies | 6-30 depending on repair calculation |
| Total wrap thickness | 5-25 mm |
| Tensile strength | 400-800 MPa (longitudinal) |
| Modulus of elasticity | 25-40 GPa |
| Service temperature | -40 °C to +120 °C standard; 180 °C for high-temperature systems |
| Cure @ 25 °C | walk-on 4 hours, full cure 7 days |
| Cure @ 70 °C | full cure 4 hours |
Standards
- ASME PCC-2 Article 4.1 — non-metallic composite repair systems
- ISO 24817 — composite repairs of pipework
- DNV-RP-F113 — pipeline subsea repair
- API 2200 — repair of crude oil, LPG, product pipelines
- NACE SP0102 — in-service inspection of pipelines
- ASTM D2992 — design basis for fibreglass pipe (related testing)
Application workflow
- Defect assessment — UT thickness mapping, defect characterization, fitness-for-service calculation per ASME FFS-1
- Wrap design — calculate required ply count based on repair pressure, defect dimensions, service conditions
- Surface prep — abrasive blast or power-tool clean to Sa 2½ in the repair zone
- Filler application — fill any deep pits or gouges with structural epoxy filler
- Wrap layup — apply pre-cut fibre layers with structural epoxy, layer-by-layer, ensuring no air entrapment
- Cure — ambient or accelerated (heat lamp / induction)
- Inspection — adhesion test, visual check, dimensional measurement
- Documentation — repair record with location, design, materials traceability, cure log
Common questions
Can I wrap a leaking pipe? Through-wall leaks need to be sealed first — typically with a Type-B steel sleeve over the leak, with the composite wrap applied over the sleeve assembly for hoop reinforcement. Pure composite-only repair on a through-wall defect requires careful engineering and is usually inferior to sleeve + composite.
Repair life expectancy? Properly engineered composite repairs are qualified for 20-25 year design life per ASME PCC-2. Many repairs in service since the 1990s are still performing.
Compatible with cathodic protection? Yes — composite wraps are non-conductive, so they don't interfere with the original CP system. The CP current continues to protect any remaining bare-steel exposure.
