The Vacuum pump employed in the OCS’s pipeline pre commissioning operation spread is a Stokes model 412-11 Micro Vac Pump with stokes 615M series blower.

The piston of this vacuum pump is driven by an eccentric mounted on the drive shaft and the piston slider is guided by two floating hinge bars that are free to oscillate in the pump housing. Air enters the pump through the intake and then through the piston slide until the piston completes one stroke. As the piston continues to rotate, the air in front of it is compressed and discharged through the exhaust valve and finally out the exhaust outlet. Lubrication of the pump internal parts is automatic when the pump is in operation. This pump also incorporates a solenoid valve which automatically prevents the oil from flooding the pump in the event of a power failure, or when the pump is shutdown without vacuum being broken. This pump is also provided with a manually operated gas ballast valve to overcome adverse affect on vacuum resulting from oil contamination.

The Stokes Vacuum M seal 6 inch blowers are standard with keyless timing, roller bearings, mechanical vacuum seal and large oil level sight glasses. This blower is single stage positive displacement unit. It also incorporates helical gears for quiet operation and maintains proper impeller timing.

The Stokes vacuum pump is associated with the services as per below

• PIPELINE PRE-COMMISSIONING