Introduction – the Steps and Sequence of the Construction Process
Many steps are involved in constructing a pipeline. This process starts with a survey to mark-out the routing established as a precursor to the design phase, which is followed by clearing, grading, and trenching. This initial phase is followed by pipe stringing, which in turn is followed by field-bending as needed, then welding and coating the pipeline segments between the girth welds to complete strings of pipe between the tie-in weld sites. These steps occur on the side of the ditch with the pipe string setting on skids. Next, the pipe strings are lowered-into the trench, which as needed includes benches for the string to rest on, to avoid damage from the trench floor if that is an issue. Details such as trench breakers and cabling for the cathodic protection system are dealt with next, with the pipe string then jeeped to ensure the coating has not been damaged. Thereafter the line is bedded and padded prior to backfilling, and the restoration of the right of way.
The Details Involved in Pipeline Construction via Videos
Several instructive videos are online that illustrate the usual construction sequence for cross-country pipelines. These include:
(Spectra now Enbridge)
Many others can be found by webcrawl using keyword combinations involving pipeline + construction.
Practices exist that have been used and proven effective for pipeline construction using the sequence noted above. While this sequence must be adapted to address rough terrain, or Arctic conditions the basic process remains the same.