External Three-Layer Polyethylene Coating

Three-layered coating provides the best and long lasting corrosion protection because of the merged excellent anti-corrosion properties of epoxy resin and excellent mechanical properties of polyethylene.

Unlike two-layer coating that is designed for the pipeline operating temperature up to 50˚C or 70˚C, three-layer coating uses the following temperature areas: up to 50˚C with low density polyethylene (LDPE), up to 80˚C with medium-density polyethylene (MDPE) and up to 85˚C with high-density polyethylene (HDPE).

Preparing the surface of the tube is performed by grit/shot blasting to ensure Sa 2½ degree cleanliness (with a steel shot and steel grit).

Coating consists of three layers:

  • Layer of epoxy resin (FBE) electrostatic applied to the heated pipe at a temperature of 180˚C to 220˚C,
  • Layer of adhesive electrostatic applied immediately after application of epoxy resin and
  • Polyethylene layer applied by sleeve extrusion.

Outside diameter of pipe (D): from 88.9 mm to 813mm.

Standard for coating application: DIN 30670, NF 49710, EN 10285.

Performing: N and S according to DIN 30670;

Coating thickness: 1.5 mm to 3.7 mm depending on a diameter of pipe, up to 8mm at the request of customer

100% porosity test – test voltage 25 kV

Cut-back: 130mm to 150mm

Protective caps or steel rings – at the request of the customer

Pipe Length: 6 meters to 12.2 meters

Each pipe has written text that contains a trademark and company name, size and quality of materials, the standard by which the pipe is made and the type and standard of making the external coating. When pipes are packaged in bundles (diameter less than 219mm), marking text is on the label fixed to each package.