SUR 881 Pump (pneumatic)
The SURE 881 is a pneumatically operated piston pump intended for use in progressive lubricating systems. The pump is capable of flow rates of 85 cc/min up to 196 bar pressure. It may be used with greases from #000 to #1. The pump is available in 3 different reservoir sizes, each having an integrated low level switch.
Air is supplied to the air inlet via a 2/2 solenoid valve. The speed of pump operation may be regulated by means of the air flow regulator. When air is fed into the pump, the air piston moves forward, pushing the lube piston forward, and ejecting grease through the outlet check valve and into the main lubrication line. As the piston nears the end of the forward stroke, it actuates the reversing valve, which dumps the air pressure through a vent hole on the underside of the pump. The piston is forced back by the return spring. In doing so, the metering chamber once more fills with grease. The outlet check valve prevents grease being sucked back from the outlet. The air piston returns to the original position, it closes the vent port, enabling the cycle to begin again. Outlet pressure is determined by the inlet air pressure and the fixed piston ratio of 28/1. The maximum flow rate achievable is 85cc/min. The pump will continue to operate until the 2/2 solenoid valve is de-activated.