-We have to survey a route, make sure that the route we’re using is easily reached. Also we have to make sure that our route is not located in areas close to the animal habitat i.e. water bodies so that oil spills won’t affect living organisms living in that environment.
-When we’ve found the route we’re going to use, we stake the area and every temporary working space required for the construction.
-After that, we clear the area, trees and vegetation are removed from the right-of-way (ROW) and the topsoil is removed and stockpiled and protected for future reclamation. We install silt fences along edges of streams and wetlands to prevent erosion of disturbed soil and for protection of the water courses. The ROW is then levelled and graded to provide a safe working space.
In order to make this process safe, we build the pipeline using carbon steel since it is: * It’s easy to weld * It can withstand high operating temperatures and pressures * It can be protected from corrosion hence less pollution to the environment * It can remain indefinitely in service if properly maintained After all this has been done, the following processes are carried out:
-Trenching Excavators dig the trench to the required depth of about 6-8 meters and place the excavated soil to the side. ---
-Stringing Individual lengths of pipe ranging from 12 to 24 metres long are brought in from stockpile sites and laid out end-to-end along the right-of-way.
Individual joints of pipe are bent using a hydraulic bending machine for directional changes and to fit the terrain.
Welders join the pipes together using either manual or automated welding processes. Both manual and automatic welds are of the highest quality, with every weld inspected and certified using non-destructive examinations including X-ray or ultrasound methods.
Coating on the outside of the pipeline is used to prevent it from corrosion or rusting. The new pipe (and any repairs to the existing pipe) will typically be coated with fusion bond epoxy. In rockier areas, enhanced external coatings such as concrete, abrasive resistant fusion bond epoxy or polyethylene will be used to mitigate the impact from abrasives or stress-concentrating conditions (such as rocks or backfill) and to provide additional mechanical protection. Prior to lowering the pipe section into the trench, the integrity of the coating is checked by means of a high voltage tool that will detect even the smallest defect in the coating. If a defect is noted, an epoxy repair coating is applied.
The welded pipeline is lowered into the trench using heavy lifting machines called sidebooms.
Valves and Fittings
Valves and other fittings are installed at intermediate locations as required by