Field-applied corrosion protection systems for girth welds, tie-ins, and repairs. The field joint is often the weakest link in a pipeline’s corrosion defense—proper material selection and application quality are critical.
1.1 Heat-Shrinkable Sleeves (HSS)
The industry-standard field joint coating for 3LPE, 3LPP, and FBE-coated pipelines. Crosslinked polyethylene backing with a heat-activated adhesive.
Applicable Standards: ISO 21809-3, NACE SP0303, DIN 30672
Sleeve Types:
Type Backing Adhesive Max Service Temp Application
Standard PE Sleeve Crosslinked HDPE Hot-melt adhesive 80°C Buried onshore 3LPE pipelines
High-Temp PP Sleeve Crosslinked PP High-temperature adhesive 110°C High-temp and 3LPP offshore
Two-Layer Sleeve PE + Butyl Mastic/Butyl 50°C Low-temp, repairs, fittings
Insulation Sleeve PE + Syntactic foam Hot-melt 80°C Subsea insulation continuity
Kit Contents (Typical):
· Heat-shrinkable sleeve (main wrap)
· Epoxy primer (two-component, field-mixed)
· Closure patch / sealing strip
· Application instructions and batch certificates
Key Selection Parameters:
· Pipe OD and coating type (3LPE, 3LPP, FBE)
· Operating temperature (continuous and peak)
· Factory coating cutback dimensions (per project WPS)
· Soil stress and burial depth
Quality Requirements:
· Peel adhesion ≥ 50 N/cm to steel (24 hours after application)
· Peel adhesion ≥ 50 N/cm to factory PE coating
· No wrinkles, bubbles, or voids
· Smooth adhesive squeeze-out at both edges
1.2 Liquid Epoxy Field Joint Coating
Solvent-free or 100% solids two-component epoxy applied by brush, trowel, or spray to field joints.
Applicable Standards: ISO 21809-3, NACE SP0303
Key Properties:
· Dry Film Thickness: 400 – 800 µm per coat
· Temperature Range: -30°C to +90°C (standard), up to 120°C (high-temp grades)
· Cure Time: 2 – 8 hours (temperature-dependent)
· Surface Preparation: Sa 2½, anchor profile 50-75 µm
Advantages:
· Seamless, monolithic bond to factory FBE or 3LPE coating
· No overlap adhesion concerns (direct bond to PE surface)
· Excellent for complex geometries (bends, tees, flanges, fittings)
· Resistant to cathodic disbondment
Limitations:
· Weather-dependent cure (humidity, dew point, temperature)
· Requires accurate mixing ratio and pot life management
· Longer application time vs. sleeve wrapping
Typical Packaging:
· Pre-measured kits (A+B components) per joint
· Bulk containers for larger repair areas
· Brush-grade and spray-grade formulations
1.3 Visco-Elastic Wrap Systems
Cold-applied, self-amalgamating wrap system. No heat required, no primer required in most cases.
Applicable Standards: ISO 21809-3, EN 12068
Key Properties:
· Application Temperature: -20°C to +50°C
· Maximum Service Temperature: 60°C (standard), 80°C (high-temp)
· Shelf Life: Unlimited (no curing, no pot life)
· Water Absorption: < 0.05% (excellent immersion resistance)
Advantages:
· No torch, no epoxy mixing, no pot life constraints
· Excellent wetting and self-healing properties
· Can be applied to damp surfaces (within limits)
· Simple removal and re-application for weld inspection
Typical Applications:
· Field joints in remote locations (no power or heating)
· Wet or humid environments
· Pipeline repairs and coating rehabilitation
· Transition zones (coated to uncoated pipe)
1.4 Petrolatum / Wax Tape Systems
Petrolatum-impregnated fabric tape. The original cold-applied field joint system.
Key Properties:
· Temperature Range: -30°C to +60°C
· Thickness: 1 – 3mm per wrap layer
· Application: Hand-wrapped, no special tools
Typical Applications:
· Temporary field joint protection
· Flange and valve body protection (above-ground)
· Buried fitting protection
· Secondary wrap over heat-shrink sleeves in rocky terrain
1.5 Field-Applied FBE (Fusion Bonded Epoxy)
Portable FBE application equipment for joints on FBE-coated pipelines.
Key Properties:
· Thickness: 350 – 500 µm
· Application: Induction heating + electrostatic spray or fluidized bed
· Cure: Rapid (seconds to minutes)
Typical Applications:
· Directional drill pullback sections (uniform OD required)
· FBE-coated pipeline tie-ins
· Project specifications requiring 100% uniform coating