BP's Fortiespipeline from the North Sea, which comes ashore at Grangemouth, carries about 700, 000 barrels of crude oil a day between a quarter and a fifth of Britain's offshore production.
The industrial action by 1, 250 workers at the plant in April was the first at any refinery in the UK for 73 years, and also led to the closure of the Forties North Sea oil pipeline.