KWH Pipe offers marine applications such as outfalls, intakes and water crossings. The pipes can be delivered in long lengths, welded on site and then sunk.

Weholite Marine 

For marine applications, KWH Pipe offers Weholite, a structured-wall polyethylene pipe with smooth internal and external surfaces for low-pressure applications up to 2 bar internal pressure. It is one of the few polyethylene pipes in the world that can be produced in dimensions larger than two metres. In fact, it is manufactured in sizes ranging from 300mm to 3,500mm internal diameter, and can be supplied in ring stiffness classes up to 8kN/m². Pipe lengths are normally 12m - 18m, but pipes can be supplied in even longer lengths depending on transport capabilities. Weholite is extremely suitable for intakes and outfalls for power plants, sewage treatment plants, refineries and desalination plants.

The main benefits of Weholite compared to alternative materials are that it is durable and light-weight, and has outstanding resistance to chemicals and corrosion, making it ideal for use in marine projects. Weholite provides all the technical advantages of equivalent PE solid wall pipes but with substantial savings in weight, combining greater ease of installation with increased cost effectiveness. Installation is quick and reliable, with the pipes easily transported to the job-site, even in poor ground conditions. Weholite pipes have a natural ability to 'flex', which enables them to adjust to different loading conditions, vibrations, stress and soil movements, without causing damage to the pipe.

Installation of marine pipelines

As polyethylene’s density is lower than water’s, pipes can be towed by tugboat to the installation site. What makes Weholite truly unique and especially suited for marine projects is that it has a hollow profile wall that can be filled with a non-hardening cement mortar mixture. This counteracts the natural buoyancy of the polyethylene while preserving the flexibility of the pipes. Internal weighting also reduces total project costs as the need for dredging is much smaller compared to pipes with external weights.

Services offered by KWH Pipe for marine pipeline projects

- Hydraulic calculations

- Strength calculations

- Material supply

- Welding and assembly work

- Installation or supervision of the installation

Advantages of Weholite Marine

- Low weight, easy handling

- 100% tightness with welded joints

- Several ring stiffness classes: 2kN/m², 4kN/m², 6kN/m², 8kN/m² or tailor-made

- Internal working pressure up to 2 bar

- Flexible at installations

- Superb with bad ground conditions

- Long service life

- Corrosion resistant material – low maintenance

- High abrasion resistance

- Delivery lengths flexible

- Good hydraulic properties

- Tailor-made fittings

KWH Pipe supplies a range of Weholite products, including pipes from 300mm to 3,500mm (tailor-made sizes are also possible), bends, T-pieces, manholes, special fittings and diffuser ports.

Solid-wall pressure pipes for marine applications

KWH Pipe also offers solid-wall PE-HD pipes for marine applications where the internal pressure is above 2 bar and for diameters below OD 1600 mm. PE-HD pipes are corrosion resistant and have high abrasion resistance. Furthermore they have a long service life and are virtually leak proof. External weighting is designed based on conditions on-site.

Project Services

Marine installations require a significant amount of experience and expertise. KWH Pipe's Project Services unit can assist in every stage of a marine project or offer a comprehensive solution.