Coating of HDD Field Joints and Tie-Ins

HDD projects require thick and very tough coatings for field joints, because the pipes and in particular the joints will be submitted to extremely high stress and abrasion, especially in rocky and hard soils.

Additionally, the field joint coating should form a perfect homogenous bond with the parent coating on the shoulders to prevent any disbondment in case that specific area is hit by any obstacle when pulled through.

Normally, a thickness of 5 mm or more is specified which is hardly achieved by Heat Shrinkable Sleeves or tapes.

PP10 Flame Sprayed coatings of 12 mm and more have been easily achieved and PP10 Flame Sprayed coatings have been qualified in a number of HDD projects.

The Flame Spray technology is particularly useful for off-shore tie-ins coating as it can coat special shapes at various coating thicknesses