Hydraulics International, Inc. (HII) air driven liquid pumps operate on the principle of differential working areas. An air piston drives a smaller diameter plunger or piston to provide a pressure ratio.

Hydraulics International liquid pumps operate at a drive air pressure of 12-150 psi (0.8-10 Bar) and will cycle automatically when compressed air is first applied to the drive. It will start cycling at its maximum speed thus producing maximum fluid flow. At this stage, the pump is acting as a transfer pump, filling the pressure system with fluid.

Click on each product below for more detail information.



■ Air Drive line lubrication not required.

■ Self-priming for immediate operation.

■ Compatible with all hydraulic fluids, plain water, distilled & deionized water, solvents, mild chemicals and most liquefied aerosol type gases.

■ Stainless steel hydraulic body, check valves, and trim are standard, except -4 and -7 models.

■ Alternative gases that can drive the pump include nitrogen, vapor from liquefied gas, pipeline natural gas and sour natural gas with proper modifications.

■ Offer a wide range of standard modifications.

■ Hydraulic pressure is held without energy consumption.

■ Explosion proof ... requires no electrical power or connections.

■ Intrinsically safe.

■ Compact, lightweight and weatherproof.

■ Easy to adapt automatic controls.

■ Contamination tolerant.

■ Outlet stall pressure pre-determined by the air drive regulator.

■ High pressure capability - up to 80,000 psi (5516 Bar).

■ Ideal for stop-start applications under full load.

■ Easy to install and operate.

■ ISO 9001: 2008 & AS9100-2009 Certified Quality System

Any questions?