Designing a gas pipeline involves:
These enable us to prepare a report about the site before work starts; this can be used as the basis of any compensation payments at the end of the work.
Once in place, this allows a constant route for machinery and storage areas for material excavated from the trench.
The pipes are transported, unloaded and arranged along the access track.
The pipes are bent on site to match the contours of the land and changes in direction along the route.
The pipes are butt-welded using techniques and procedures meeting currently applicable standards and regulations.
The welded joints are x-rayed to ensure that the pipeline has been assembled correctly.
The welded joints are encased in corrosion-resistant sleeves.
Earthmoving is carried out in two stages, to separate the subsoil at the base of the trench from the topsoil.
The quality of the corrosion-resistant coating is checked just before the pipe is lowered into the trench.
The pipe is progressively laid along the bottom of the trench, taking advantage of the elastic properties of the steel in the pipes.
A precise survey of the pipe is conducted so that a map can be drawn which accurately records the work carried out. Those maps are submitted to the local town hall.
The trench is backfilled in two stages, ensuring topsoil is restored to the surface layer.
The pipeline is filled with water and then tested at a pressure of approximately 100 bar to make sure it is fully gas-tight before being filled with gas. This operation is carried out under the supervision of an authority (DREAL) representative.
The land is fully returned to its original state. Ditches and embankments are re-established, and field boundaries rebuilt. Soil which has been flattened by the machinery is decompacted by subsoiling.
These enable us to assess damage caused and to work out the amount of compensation payable.
For more information, see: