The NAPCO rotary gear pump is available in 316 stainless steel and ductile iron, and can handle a broad range of pumping applications from water to highly viscous or abrasive fluids. It can also handle some corrosive fluids. It comes fully lubricated and ready for use. It operates clockwise or counter-clockwise with equal efficiency. The rotary gears come standard in high temperature nitrile rubber, but neoprene, viton and other gear material can be ordered to handle special higher temperature or corrosive fluid applications.
NAPCO rotary gear pumps are positive displacement pumps. As the rotary impeller turns, the gear teeth open, creating an expanding cavity on the inlet side to vacuum fluid into the pump chamber. The impellers carry the product around the pump cavity to the outlet side and, upon meshing on the outlet side, force the fluid out of the pump.
The drive gear and idler gear are the only moving parts in the pump. The outer lip seals (low pressure) and inner seals (high pressure) ride on especially hardened shaft surfaces. The four inner high pressure seals seal the pump chamber and the four outer lip seals create lubrication chambers. The two shafts ride on four outboard roller bearings –one on each shaft end-- that are spatially separated from the seals and pump chamber by weep holes in the bearing housings/side covers. Anti-cavitation traps on the inside walls of the bearing housings/side covers minimize shaft flex that would otherwise result from product being trapped between the meshing gears. The discharge ports are designed to allow the gears to rotate and move product in either direction through the pump chamber.