Coatings & linings
During a service life extending over many decades, large-diameter pipes are frequently exposed to environmental extremes. Therefore, reliable coatings for protection against corrosion and mechanical damage are indispensable in most cases.
We provide our pipes with coatings and/or linings to customer requirements and/or in line with applicable standards. Our offering includes:*
Before coating/lining, our pipes can be subjected to a high-pressure water scrub.
Besides passive corrosion protection, an epoxy lining reduces the surface roughness on the pipe inside surface – and thus the flow resistance – to a minimum, which is particularly beneficial in the case of gas pipelines.
Other coatings and linings are available on request.
Polyethylene (PE) coating
Before coating, the pipe is dried, externally shot-blasted to SA 2.5 requirements and then inductively heated to about 220 °C. This is followed by a primer coat of electrostatically applied epoxy resin (EP) powder with a thickness of 60 to 255 µm. Then a single layer of an approximately 125 to 400 µm thick adhesive foil is wound over the EP. Finally, a PE foil is wound over the adhesive. The pipe ends are left uncoated and, if required, provided with temporary corrosion protection. As added protection against rust creep during extended on-site storage, the transition area from the PE chamfer to the bare pipe end can be provided with a bituminous coat.
Polypropylene (PP) coating
At service temperatures above 80 °C, a coating's indentation resistance becomes increasingly critical. In such cases, we recommend a 3-layer coating system in which the third layer consists of polypropylene. In all other respects the build-up of the 3-layer PP coating system is the same as of the 3-layer PE coating system. Here too, the pipe ends are left uncoated and can be provided with temporary corrosion protection. A bituminous coat can be applied to the transition area from the PP-chamfer to the bare pipe end.
Epoxy resin lining to API RP 5L2 is mainly used on gas line pipe. Its purpose is to reduce the pipe's surface roughness and thus flow resistance inside the pipeline for increased transportation efficiency.
At our coating facility, the airless spray technique is used to apply a low-solvent 2-component epoxy resin lining to a dry thickness of at least 60 µm.