BBC Website 5 July 2011
The owners of Grangemouth refinery have been fined £100,000 over a spill of highly flammable oil. In the incident, a pipeline became pressurised and sprayed crude oil across a nearby pumphouse and pipelines containing other dangerous liquids.
An investigation found the company had been aware of the risk and the need to install controls.
But it also found Ineos chose to rely on staff to reduce pressure by manually draining oil from the pipeline, and storing it in a skip that was not designed for storing oil.
Further information from SHP magazine 8 July 2011
An incident occurred in May 2007 that resulted in more than 100 litres of crude oil being released on to the floor of a pumphouse. The HSE advised the company to install a hydrostatic release valve, which would divert some of the oil to a storage container once it reached a certain pressure.
However, INEOS failed to act on this suggestion, and it continued to be common practice to allow pressure to build up in the pipes until a warning alarm sounded in the control room when the pressure reached 19 bar. The controller would then instruct a field operative to drain oil from the pipeline to release the pressure.
On 7 May 2008, following a shift change in the control room, staff became confused by the method of work. When the pressure alarm sounded, the controller was unaware that the method of work required him to arrange for the pressure to be released manually. Four hours after the alarm sounded a gasket on the pipeline ruptured and oil began spraying across a nearby pumphouse and adjacent pipelines containing other dangerous substances. Nobody was injured during the leak but it posed a serious risk of causing a fire, or explosion.
According to HSE "Despite having recognised the need for engineered thermal relief on their crude-oil pipelines, following an incident at their refinery a year earlier, INEOS chose instead to rely on a manual system for managing thermal expansion. This system of work actually increased the risk of fire and explosion and ultimately failed to prevent the pipeline from becoming over-pressurised. The risk of over-pressurising pipelines and storage vessels, as a result of thermal expansion, are well-understood, as are the required control measures."