Gear pumps use intermeshing gears to pump various types of liquids. Typically, one gear is the driver and the other is free wheeling. The gears have very tight tolerances so that the fluid being pumped cannot pass through them. Common uses for gear pumps include high pressure, metering, and flow control applications.
Piston pumps and plunger pumps are reciprocating pumps that use a plunger or piston to move media through a cylindrical chamber. The plunger or piston is actuated by a steam powered, pneumatic, hydraulic, or electric drive. Piston pumps and plunger pumps are also called well service pumps, high pressure pumps, or high viscosity pumps.
Positive displacement pumps use a mechanical force such as gears, bladders, pistons, plungers or diaphragms to push liquid through and out of the pump.
