The Top Gear API 676 internal gear pump TG-G, TG-H and TG-L, are suitable for general purposes duties, high demand applications and low viscosity fluids. All three models have a rotor and idler in the pump case that un-mesh, resulting in an under pressure being created and the liquid entering the newly created cavities between the rotor teeth and the idler. The liquid is then transported in sealed pockets to the discharge side. The pump casing walls and the crescent create a seal that separates suction from the discharge side followed by the rotor and idler meshing and the liquid being pushed into the discharge line.
The Johnson Pump Top Gear TG-G, TG-H and TG-L pumps have small radial clearances which reduce slip and improve rotor/gear shape. In the TG-L pump, the large vertical ports help improve the priming capability and reducing the risk of cavitation. The pump and motor are also flange mounted to pedestals to achieve correct alignment between the pump and the drive shaft.