High Density Polyethylene (HDPE) Coated Ductile Iron Pipes

Samsun Makina PE series ductile iron pipes are designed for use in very high corrosive soils. High density polyethylene (HDPE) coating material is extruded and applied on the pipes coated with minimum 200 g / m2 zinc.

Physical properties of polyethylene (PE) material comply the below requirements:

Property Requirements
Melt Flow Rate 0.2 to 1.0 g/10 min
Density 0.910 to 0.960 g/cm3

PE coating generally consists of two factory applied layers:

  • an adhesive layer applied; and
  • an extruded PE compound outer layer applied by the flat die wrapping extrusion method immediately following the application of the adhesive. The different layers are welded together by means of a pressing roll

Due to the thickness of the polyethylene coating, ductile iron pipes are fully protected not only against the high corrosive soils but also against the damages during lifting and transportation.

The coating thicknesses of PE series pipes are much higher than other coating types (bitumen, epoxy, polyurethane, etc.):

PE EXTERNAL COATED PIPE Standard Thickness (µm) Increased Thickness (µm)
DN 80 - 100 1800 2500
DN 125 - 250 2000 2500
DN 300 - 450 2200 3000
DN 500 - 700 2500 3500
DN 800 - 1400 3000 3500
DN 1500 - 2000 3500 4000

PE coated ductile iron pipes are produced according to the EN 14628 standard. The European Standard defines the requirements and test methods applicable to factory applied extruded PE coating for the external corrosion protection of ductile iron pipes conforming to EN 545, EN 598, ISO 2531 and ISO 7186. The SMS pipes have been conformity tested to fulfill the below performance requirements of the EN 14628 standard:

Parameter Performances
Pealing Strength 10N (Zn-coated surfaces)
Impact Strength Fig 2, Range A
Indentation Resistance < 0,3 mm
Elongation at break > 200 %
Specific Coating Resistance in 0.1 M NaCl > 108 Ωm2
Ratio of Resistance > 0,8
Heat aging 100 days 100 °C < ± 35 %
Light aging 100 days xenon arc radiation < ± 35 %
Saponification properties of adhesive Saponification value < 3 mg KOH/g

The following order information shall be supplied by the purchaser besides the standard product data according to EN 545, EN 598, etc.:

  • PE coated DI pipe in accordance to EN 14628 standard,
  • Coating method either:
    • Standard thickness, pipe zinc-coated,
    • Increased thickness, pipe zinc-coated,
    • Standard thickness, pipe not zinc-coated or
    • Increased thickness, pipe not zinc-coated.