High pressure condensate pumps are an integral part of the gas processing system on offshore platforms. The Piper had two of these pumps, which were identified as condensates pumps A and B. These were located in the gas processing module "C," with one operating and one on standby. As well as being exported to MCP-01, Piper also used the processed gas to fuel the main power generators that supplied the electricity to the platform.
On the morning of the accident on July 6, 1988, a Pressure Safety Valve (PSV #504) had been removed from pump “A” for routine calibration checks, with the statutory “Permit to Work” being raised and left in the Main Control Room.
Two blanks (machined blind flanges) were bolted to the inlet and outlet flanges, in place of the removed PSV, as shown below.