Revêtements intérieurs - canalisations en fonte ductile - Saint-Gobain PAM

PUR - Internal Polyurethane

Technical solutions


The PUR range from DN 100 to 2000 features a polyurethane coating deposited on the pipes in the factory. The ends, socket and spigot, are protected by a thick epoxy coating.
This PUR range is intended for use with highly aggressive water with respect to cement mortar. It completes the NATURAL or CLASSIC ranges where the cement mortar coating cannot be used.

A polyurethane coating applied in PAM plants

The polyurethane lining is deposited inside the pipes in the PAM plants. Internal manufacture ensures rigorous control of the coating application conditions. The polyurethane used by PAM is a solvent-free two-component system. The pipe is heated to a temperature at which the coating can be sprayed on.

For pipes in the PAM PUR range:
– the inside of the pipe barrel is coated with polyurethane,
– the outside of the spigot and socket are coated with zinc-rich paint and epoxy.

Highly demanding technical specifications

Due to the thickness of its polyurethane layer, the ductile iron pipe is fully protected against the most aggressive water as well as during transport and handling operations.

Thickness of polyurethane coating on PUR pipes

DNAverage thickness μmMinimum thickness μm

The PUR coating complies with European standard EN 15655.

Technical specifications of the Polyurethane coating according to EN 15655

Refer to EN 15655 for the precise
definition of the test methods
1Chemical resistanceLess than 15% weight increase after immersion
in deionised water
Less than 2% weight loss after drying
1Chemical resistanceLess than 10% weight increase after immersion
Less than 4% weight loss after drying
2Indirect impact strength

8j/mm of PU on the pipe barrel coated with

3Resistance to ovalisation

Static deformation test
2% from DN100 to 250, then 4%
3% from DN 300 to 600, then 6%
4% from DN 700 to 2000, then 8%
After examination, no damage to the coating

4Elongation at break>2.5%
5Specific resistance of the coating
in 0.1 m NaCl solution
6Resistance ratio>0.8
7Resistance to light ageingAdhesion great to 8 MPa after 6 months'
outdoor storage
8Non-porosityNo breakdown with Holiday detector at 3kV
9HardnessShore hardness > 70
10Adhesion>8 MPa to 20°C


The PUR coating can be used for water at permanent operating temperatures up to 45 °C.
The PUR coating is suitable for water of pH between 1 and 13.

See also

The internal protection guarantees that the hydraulic performance of the pipe is maintained long term, prevents any risk of internal attack by the waters carried and maintains the quality of water carried.