Pipeline coating and wrapping

Line pipe arrives factory coated. The joints do not. Every weld on a buried pipeline is coated in a trench, by hand, often in heat and wind — which is precisely why field joints account for the majority of coating defects found when a line is eventually excavated.

Systems

Heat-shrink sleeves

Cross-linked polyolefin sleeves with an adhesive backing, positioned over the prepared joint and shrunk down with controlled heat. The preferred field joint system where the parent coating is polyethylene or polypropylene, because the materials are compatible and the bond is continuous.

Tape wrapping

Petrolatum, bituminous or polymeric tape applied with a specified overlap over a compatible primer. Used for field joints, fittings, valves, bends and irregular geometry that a sleeve cannot follow, and for rehabilitation of existing buried assets.

Application control

• Surface preparation to the system’s stated standard, with mill scale and contamination removed
• Preheat to the specified temperature and verified with a contact thermometer
• Primer applied within its stated open time
• Overlap onto the parent coating to the specified distance
• Shrink or wrap tension controlled, with no voids or air entrapment
• Holiday detection across the full coated surface at the specified voltage
• Coating defects repaired and re-tested, not recorded and left

Also covered

• Rehabilitation coating of excavated existing pipelines
• Coating to valves, fittings, bends and buried steelwork
• Mechanical protection and rock shield before backfill
• Coating of exposed above-ground pipework and risers

Standards we work to

• ISO 21809-3
• ISO 21809-1
• EN 12068
• NACE SP0169
• ASTM G62
• DIN 30672