-
Inter-shop gas pipeline is a system of pipelines for supplying gas to two or more workshops or to one workshop with a length of more than 100 m. It usually includes many linear sections. For its assembly, sections made in pipe-procuring shops no more than 40 m long are used. Their size is limited by the technical equipment of the installation team, the availability of rigging equipment and the capabilities of the site where the structure is installed.
Depending on the location, pipelines are divided into those that pass inside the building or outside. The design of pipelines should provide ease of assembly, the possibility of access to its sections for condition control. Installation of intershop gas pipelines in accordance with PB 11-401-01 “Safety Rules in the gas industry of metallurgical and coke-chemical enterprises and industries” is performed only by ground method on overpasses, racks or supports.
For laying pipes, walls and roofs of structures are used, taking into account the characteristics of gas pipelines, the fire resistance class and the fire hazard category of buildings. When designing, terrain features are taken into account, calculations are performed, pipe laying drawings are prepared taking into account the requirements of manufacturers of technological equipment and operating conditions. The standards for the remoteness of the overpass from the ground must be maintained if there are pedestrian passages or carriageways under them.In preparation for the installation of inter-shop gas pipelines, a number of works are carried out:
- By this point, construction work should be completed: the installation of foundations, precast concrete elements, fixed supports.
- Geodetic survey is carried out in order to check the correctness of marking on the intermediate racks. An act of conformity of marks to the project bias is drawn up.
- Mobile devices (forests, scaffolds) are being prepared, installation equipment provided for in the RWP is being installed.
- Sections and pipes are delivered, sorted and placed along the track. All elements of the gas pipeline are inspected, cleaned of dirt and rust.
Installation of the intershop gas pipeline begins with the installation of sections on overpasses with the help of lifting cranes or pipelayers. Work begins from a fixed support, with two-tier overpasses, the bottom row is first mounted.
Part of the sections of pipelines on the ground are installed on overpasses, and installation is made in enlarged blocks. Immediately after installation of the block, its mounting is performed. The pipes are attached to the project condensate traps, shut-off valves, metering devices.
The welds shall not coincide with the anchorages to the supports. If thermal insulation of the pipeline is necessary, it is carried out before the installation and assembly of sections. Installation of pipes is carried out by welding, using GOST 16037-80 “Joints of welded steel pipelines”. Principal types, structural elements and dimensions.” Inter-shop gas pipelines are welded with joint, flyover, angular connections.