Special applications


Today, ZMU coating, retained by PAM China, is a protection system including several layers deposited successively on the external wall of the pipe:

  • First layer consisting in the deposit of 99.9% pure zinc by electric arc spraying, with a surface density of 200 g/m2.
  • Second interstitial layer of a glue paint containing epoxy resin in thickness ranging between 70 and 100 µm.
  • Last layer of a cement mortar, composed of fine sand, high-strength cement, a polymer dispersion and specific admixtures. The nominal layer thickness is 5 mm.

Product Range

Field of use

Horizontal directional drilling.This type of pipe laying is suitable for crossing under obstacles, rivers, motorways, without recourse to an open trench and without disrupting the activity on the surface.
ZMU pipes are used wherever high mechanical loads are to be expected, besides horizontal directional drilling, ZMU pipes can be used even in highly aggressive soils of floor class III or in rocky soils. The ZMU coating prevents the entry of aggressive media.

Working Mechanisms

For trenchless pipe laying, PAM has designed a particularly effective anchoring system which guarantees optimum sealing and flexibility while withstands pulling forces.
The fiber-reinforced, plastic-modified cement mortar coating on the exterior ensures the safety of the pipe against the resistivity of soils and rocks during the pulling process.


The ZMU for HDD pipe adopts UNIVERSAL Ve joint, which enables the joint to be flexible, sealing and strong pulling-force resistant. Taking DN600 for example, the UNIVERSAL Ve joint can withstand pulling force over 850 kN. The exceptional mechanical strength of UNIVERSAL Ve type anchored joints combined with their ability to high angular deflection enable a very long pulling distance. For example, PAM China has successfully conducted HDD projects as long as 564 m and 336 m for DN400 and Dn600, respectively.
The ZMU coating provides a protection layer against impacts during transportation, pulling or laying process. Additionally, it also ensures the longevity of pipes during the service process by its strong anti-corrosion property.
Saint-Gobain PAM has experience over 5 years using ZMU pipes in HDD projects in China. The total trenchless laying length with ZMU pipe in China is about 10 km till 2017. The accumulated experience enables PAM to provide the best trenchless solution to our customers.


Water supply: GB/T 13295, ISO 2531
Sewage: GB/T 26081, ISO 7186
ZMU layer: EN 15542


All projects are supported by customized assistance which guarantees the success of the pulling operation, including:
Pre-sales technical consultation
Product usage guidelines
On-site guidance on joint installation, water-pressure test, etc.

See also

Ductile iron pipes DN 300 to 1000 can be laid without a trench using either techniques: new pipe laying by horizontal directional drilling (HDD), or trenchless replacement of existing pipes.