Intermediate Pressure Diversion
Hilton Road, Alloa
Scotia Gas Networks
The project involved the laying of a 100m new section of 200mm diameter welded steel 7 Bar Intermediate Pressure main to abandon an existing short section of 200mm steel pipework, to facilitate the removal of 3 No. faulty steel valves.
This Project included deep excavations, welding & hot tap works, flow stopping and various live gas operations.
We identified at an early stage that we would be required to carry out deep excavations for connections to the existing 200mm I.P. mains at both ends of the diversion, with restricted access at both sides.
Trial pits were excavated by hand to locate the exact position and depth of both the mains at the required connection points.
Both pits were shored and the hot tap under-pressure tees were welded onto the existing live mains.
Once the hot tap connections onto the existing mains were completed, the new 200mm welded steel main was fabricated and installed. This was subjected to a hydrostatic strength test and a final air test before being commissioned.
The final part of the works was the flow stopping and capping off of the old 200mm main, this was completed successfully, as was the final wrapping, construction of the pipe supports & all backfilling and reinstatement works as required.