Alert 13 – 09 High Pressure Release Results in Injury
The maintenance team, consisting of three crew members, had been involved in stripping a pulsation damper’s bottom plate, which had a damaged seal groove. Prior to starting the task, the crew checked the pulsation damper gauge for pressure and verified a zero pressure reading. After unscrewing all flange mounting studs and Allen-screws from the bottom plate, the crew started to remove the bottom plate with the extractor studs, which enabled them to move the bottom plate slightly. As per the advice of the crew supervisor and in order to remove the stuck bottom plate, it was decided to utilize the two inserts in the gap between the bottom plate and dampener body in combination with the extractor studs. While two of the crew members forced the bottom plate open with wedges from opposing sides, another crew member (injured person), who was positioned in front of the bottom plate, was using the pneumatic spanner to screw-in the extractor studs. Without warning, the diaphragm burst out due to the pressure inside, resulting in the bottom flange being discharged from the pulsation dampener. The bottom plate struck the injured person on the thigh of his right leg, throwing him approximately 6 meters (20 feet) due to the differential pressure wave, and causing serious injury to his right leg.