FILTERING OUT PREMATURE PUMP SEAL FAILURES IMPROVES MTBO

CHALLENGE

A gas extraction plant in Algeria suffered continual production problems due to failure of mechanical seals on its BB1 and BB3 gas pumping packages, despite the use of very hard materials for the stationary and rotating seal rings (silicon carbide / carbon). Investigation revealed that the mechanical seal faces were being damaged due to the presence of solid particles in the pumped liquefied gas, despite the presence of a filter at the pump’s suction. The filtration system was satisfactory for all other parts of the pump except the mechanical seals.

SOLUTION

The aftermarket team at ClydeUnion Pumps designed, manufactured and installed a secondary filtration system to remove particles from the flush for the mechanical seals. It is equipped with two filter cartridges, so that filters can be replaced without having to stop the pump. The duplex filter system also features a pressure sensor with an alarm, which alerts when a cartridge is clogged. A valve system allows the clogged cartridge to be isolated and the fluid to flow through the other clean cartridge without disrupting production.

OUTCOMES

The pump has operated well since the installation of the secondary filtration system and start-up, with no abnormal failure of the mechanical seals. The Mean Time Between Outages (MTBO) has increased from three months to more than 18 months.