Sun Qingjun, Liu Tongxi and Zhang Tianjun
Papers # 2016 Berlin
A new composite PE pipe for pressure applications has been developed which combines the following features: polyethylene based, of structural wall, of multiple layers and steel reinforced. Another outstanding feature of this product is that large diameters up to dn2200-2600mm can be made and higher ring stiffness is achieved, at much lower cost. In this pipe two reinforcements are used: steel meshes embedded in pipe wall and steel strips vertical to pipe wall. In production, layers of composite profiles are spirally wound and welded together to form the pipe, while the profiles are prepared by means of composite extrusion. Both profile preparation and pipe forming are accomplished on one continuous production line. Traditional electrofusion technology is used for pipe jointing, but a pioneering jointing element is introduced, i.e. multilayer steel reinforced PE electrofusion belt.
The diameter range of the pipe is dn200～2600mm, PN varies from 6 to 12.5bar, and ring stiffness of all diameters are greater than 10KN/m2 . Commercial production for dn315-2200mm has started ever since 2013. Laboratory tests and engineering practices has verified that all design criteria are met.
The pipe boasts quite a few benefits in comparison with other kinds of composite PE pipes and solid wall PE pipe, e.g. great raw material savings, high ring stiffness, good structural and dimensional stability, greatly-increased production speed, quick and reliable pipe jointing and low overall project cost, etc. Main applications include medium and large diameter water transmission lines from water sources, water mains in cities and towns, pressure drainage and sewers, water conservancy irrigation, intake and discharge pipelines in seawater desalination projects, etc.