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April 2022

Duesseldorf International Airport


PLASSON LightFit wastewater program guarantees leak-proof pipe connections and manhole connections for major construction projects at Duesseldorf International Airport, Germany

Flughafen Duesseldorf GmbH has been expanding and renovating its rainwater treatment and waste water drainage systems at great expense for years. In these large construction projects, those responsible rely on fully welded wastewater sewers, especially in sewer construction. The PLASSON LightFit wastewater program is used, which guarantees long-lasting, tight pipe connections and manhole connections in the sense of a fully welded sewer network.

Duesseldorf Airport ( is the third largest airport in Germany and the largest in North Rhine-Westphalia (NRW). More than 20 million passengers can fly to over 180 national and international destinations in around 50 countries with up to 60 airlines. This makes Duesseldorf Airport the most important international hub for the state of NRW. The high performance of the Airport results from a perfectly functioning and coordinated infrastructure. The existing sewer network with the associated special structures also makes an important contribution to performance. Especially when it rains, the sometimes-enormous amounts of rain that fall on the sealed areas of the airport, such as the runway and taxiway areas, must be drained off quickly and reliably in order to ensure safe airport operations. Against this background, several systems for rainwater treatment and drainage, including sewage systems, were successfully renovated by Flughafen Duesseldorf GmbH as part of various large-scale construction projects.

The “RKB Ost” project involved the construction of a new 5,400 cubic meter rainwater treatment system, two stormwater treatment tanks each with a capacity of around 1,500 cubic meters, a pumping station, a light liquid separator, an operating building with the control and monitoring electronics and, especially in the rainwater tank area, several hundred meters of newly laid wastewater sewages made of weldable plastic pipes made of polyethylene and numerous concrete manholes (see Fig. 1).

Fig. 1

Construction of the 5,400 m³ rainwater treatment system. In the background the huge concrete manholes into which the LightFit manhole adapter system will be integrated.

With the project “U81”, Duesseldorf Airport will be connected to the city rail network in the future. The implementation will take place in a total of four construction phases with planned commissioning in 2024. The total costs are around 230 million euros. During the construction process, the existing supply and disposal pipelines are laid out of the required construction site. In this context, welded sewage pipes up to a dimension of 800 mm are laid outside the construction site of the shell construction measure (see Fig. 2).

Fig. 2

PE wastewater sewer with concrete manhole, welded with PLASSON electrofusion fittings.

Conditions speak for fully welded sewage system

In view of the sewers to be laid, in particular, those responsible decided to use a fully welded PE sewer network based on years of excellent experience from previous large-scale projects. PLASSON LightFit waste water fittings are used, such as fully welded manhole connections, electrofusion couplers and wastewater connecting saddles up to d 800 mm, which result in safe, watertight pipe and manhole connections designed for sustainability (see Fig. 3).

The core of the massive overall is construction of the three rainwater tanks
and the pumping station. However, special attention was also paid to construction of the required canal system, which connects the rainwater tanks to the pumping station via appropriate manholes.
Use of welded pipe connections and manhole connections is essential to ensure that no sewage gets into the ground and groundwater in an uncontrolled manner or that groundwater does not infiltrate the sewers.
As these sewers reach a depth of 9.0m below ground, seasonal rising of groundwater can lead to pipe system overflowing, to which the welded system provides a good solution.

Fig. 3
Laying the sewage pipes and
manhole connections.

Order for welding work on the PE sewers and electrofusion fittings went to WIDDIG Pipelines Construction GmbH.


״Thanks to the trusting and professional cooperation between the civil engineering trade, PLASSON GmbH and us as the executing company, smooth material logistics were ensured at all times during the entire construction project, which is absolutely necessary for the successful completion of this type of complex construction work.״
Frank Widdig clarified Managing Director, WIDDIG Pipeline Construction GmbH
״With the LightFit concrete manhole adapter, our engineers in PLASSON Ltd. have developed a fully welded manhole connection system that guarantees an angle ability of up to 3.6° degrees with simultaneous external watertightness. The unique properties of the system were furthermore confirmed by an independent, neutral
explains Markus Engelberg Technical Manager, PLASSON GmbH
״The successful implementation of this major project once again underlines PLASSON's strong bond with the customer, both in the entire logistics chain from the dealer to the processor to the end customer, as well as on a technical level through well-founded professional advice, technical support and, in particular, in the realization of customer-specific requirements.״
Sandro Eller-Vainicher Managing Director, PLASSON GmbH

Tight manhole connection with the PLASSON LightFit concrete manhole adapter

When laying and processing the PE pipes and fittings, particular attention was paid to connecting the sewers to the precast concrete and in-situ concrete manholes. Material transitions or manhole connections in particular, often represent weak points of a drainage system when it comes to the criterion of tightness.
In order to ensure a reliable, watertight and durable manhole connection, the decision to use a fully welded manhole connection system was made as early as the planning phase. With use of PLASSON LightFit concrete manhole adapter, a component is available for this application to permanently connect sewers made of
PE to the concrete manhole in a tight and root-resistant manner, while at the same time reliably meeting requirements for flexible manhole connections (see Fig. 4).

Fig. 4
Left – practical tests of
angleability and tightness
on a scale of 1:1
right – FEM analysis with
strength and deformation
analysis of the manhole

PLASSON LightFit manhole connection system consists of the concrete manhole adapter and a corresponding electrofusion coupler. In practice, installation of the concrete manhole adapter already takes place in the concrete plant, where it is professionally integrated into the precast concrete manholes. The manhole adapter is then homogeneously welded to the supplied electrofusion coupler and the PE pipe on site. As part of the large-scale project, precast concrete manhole bodies with an individual weight of up to 28 tons were manufactured in the concrete factory and delivered to the construction site with the integrated LightFit concrete manhole adapters (see Fig. 5).

Fig. 5
Factory-integrated PLASSON
LightFit concrete manhole adapter

On the other hand, it was necessary, particularly due to the huge manhole structures constructed using in-situ concrete, to anchor the concrete manhole adapter precisely with reinforcement and form it on the construction site.
This took comparatively more time to process and required manual formwork for the manhole adapter. But here, too, the installation quality is completely convincing: all PLASSON LightFit concrete shaft adapters were professionally and safely integrated into the in-situ concrete manholes (see Fig. 6).

Fig. 6
Inspection of the manhole
connections manufactured on
site. right: Avi Blau, Technical and
Standardization Manager with
Yoav Livne, manager of the R&D
Department, PLASSON Ltd.

connections, connection saddles and manhole connections would also be used in this dimension range. This required a custom-made product according to customer requirements, especially for the necessary manhole connections, since commercially available welded manhole connection systems are usually available up to d 630 mm.
The technicians and engineers from PLASSON Ltd. R&D department then took over the development and construction of a manhole adapter for the special size d 800 mm based on existing system and production drawings and combined the concrete manhole lining with an 800 LightFit electrofusion coupler. After being appraised by the planning
engineering office, the custom-made product created in this way was specified as the lead product in the tender and was thus specified (see Fig. 7).

Fig. 7
Product and installation:
custom-made LightFit manhole
connection-system in dimension
800 mm.

As part of the project, a LightFit manhole connection-system in the dimension d 800 mm was welded for the first time in Germany. Thanks to the excellent and fast cooperation between PLASSON LTD and PLASSON GmbH, the large-diameter pipe project could be realized to the complete satisfaction of the customer.

With implementation of the major construction measures at the airport, latest state of the art is now being met. The airport operator is thus making a safe start into the future. The fully welded wastewater system made of polyethylene makes an important contribution to environmental protection and sustainable use of materials.

With PLASSON LightFit wasterwater program, permanently tight and durable connections are created as a result.