SPIE SAG Group
Language

The right connection.
Whatever your plans are.  

SAG – Your reliable partner for projects of any size.  

With high-pressure to the line

With high-pressure to the line

Supplying biogas to the Mittelhessen line

A biogas and composting facility had to be connected to the Mittelhessen line. The tight schedule posed the biggest challenge.


Due to regulations set out in the German Renewable Energy Sources Act, EnergieNetz Mitte is obliged to feed the biogas produced and processed in a
biogas and composting facility into the 16 bar gas grid. To do that, the plant had to be connected to the Mittelhessen line. Planning and project management was carried out by the client EnergieNetz Mitte. SAG in Alsfeld was commissioned with the construction work. TÜV Hesse was responsible for overseeing the building work and acceptance of the line.

“The tight schedule posed the biggest challenge. One aspect that influenced this was the completion date for the biogas plant,” explains Hans-Peter Hämer, head of the Pipeline Engineering department in the Alsfeld branch. “We also had to contend with the fact that the weather at the end of the year would leave part of the route flooded. This also had an effect on the material selected for the pipes.” The winding course of the route also crossed several roads and a stream.

Trenchless laying
The HexelOne high-pressure pipe with protective sheath from egeplast was used for the supply line. The flexible pipes are 100 percent polyethylene, withstand pressures of up to 16 bar and can be laid with no or little need to dig a trench. The plastic pipes were laid for a length of 3,000 meters.

“We laid around 2,300 meters of the line using the plowing procedure and 130 meters in open trenches,” continues Hämer. Under roads and the stream, the line was laid within a protective pipe using flush drilling. The pipes were connected using combined welding (butt welding and additional socket welding) and special press-fit connectors (sliding sleeve technology). Client EnergieNetz Mitte was very satisfied with how the project progressed and with the materials used.