GRP pipes with Hobas centrifugal casting technology

Our promise: a solid sewer upgrade for solids-free wastewater

Hobas Technology

Amiblu pipes produced with the Hobas centrifugal casting technology are made of chopped glass fiber, thermosetting resins (e.g. unsaturated polyesters or vinyl ester resins), minerals, and silica sand. The pipes are circular with an even outer diameter.

Amiblu pipes with Hobas technology are produced by centrifugal casting in a 100 % computer-controlled process. The manufacturing machine’s arm feeds all raw materials – chopped glass fibers, thermosetting plastics (unsaturated polyester or vinylester resins), and reinforcing agents – into a fast-rotating mold. Layer by layer, in a predefined process, the pipe wall is built up from the outside inwards. The material quantities inserted by the machine are monitored and compared to the desired design values in order to assure that each product is fully traceable with respect to its raw material types and quantities. Once all raw materials have been inserted into the mold, the speed of rotation is increased. High centrifugal forces of up to 75 g press the materials against the mold wall and condense them to a maximum, creating a high quality, very solid and void-free pipe wall. Cold water is used to cool the mold and after the pipe is removed, the pipe ends are trimmed and beveled. Finally, a coupling is mounted onto one end of each pipe.

The centrifugal casting process ensures that the pipes are circular, the wall thickness is uniform over the entire length at exact outer diameter, and the material displays a high longitudinal compressive strength that is particularly important for jacking. Thanks to the three-dimensional chemical bonding of the thermosetting resin, the pipe retains its stability even in very warm environments. The sandwich construction of the wall also ensures that the pipes can withstand high loading without any trouble and enables the pipe’s strength to be customized to suit the specific load directions required.

Technical data Amiblu pipes with Hobas technology*

Main materialsresin, glassfibers, sand
Operating temperature-50 °C to +70 °C, higher temperatures may be considered for individual projects
Standard lengths6 and 3 m, other lengths on request
Pressure rangePN 1-24
Expected service lifemore than 150 years
Corrosion protectionnone needed, as materials used are inherently resistant to corrosion
Hydraulic roughnessk = 0.01-0.016 mm (Colebrook-White)
Water jetting resistancetested according to DIN 19523

*As currently manufactured and distributed by Amiblu for European markets. For the full range of products with Hobas technology please refer to the Hobas website

Amiblu projects realized with Hobas technology

Delivery of Hobas jacking pipes to Bristol, UK January 2021

Bristol, Gipsy Patch Lane, structual rehabiliation with Hobas pipes

Gipsy Patch Lane, Bristol is a main road forming part of a new…
Rury Hobas PU Line Zbiornik Roztoki Bystrzyckie, Polska

Rury Hobas PU Line w projekcie budowy zbiornika Roztoki Bystrzyckie

System przelewowy suchego zbiornika przeciwpowodziowego Od…
Kent Brewers Bridge

Kent, Brewers Bridge, Culvert strengthening with Hobas relining pipes

Kent County Council‘s programme of planned highways maintenance…


Technical data

Diameter, pressure, stiffness, and so much more… All the technical hard facts you need to plan, lay, and operate our pipelines.


Reference database

Over 30,000 projects in over 125 countries in over 60 years: Discover spectacular and technically challenging construction works with Amiblu’s technologies (Flowtite, Hobas, Amiblu, Amiscreen) in our reference database.


Our footprint

We aim to have life cycle assessments for all products by end of 2022 and a carbon-neutral pipe production by 2030. We use the resources we have—our business, our voice, and our network—to fight the climate crisis and inspire people around the globe to value water as we should.