3L-SS-14 : HII Air-Driven Liquid Pump, 3" Single Acting, Single Air Drive, 1950psi, 0.46in3 (7.53cc), 3/4" NPT Inlet, 1/2" NPT Outlet, Hydraulics International, 316SS Hydraulic Body, 316SS Hydraulic Plunger, 316SS Check Valves, Buna-N Static O-Rings, UHMWPE Plunger Seal, Hydraulics International, Inc., also called 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. The pressure ratio is the method of determining maximum outlet pressure available. Hydraulics International model numbers reflect the nominal pressure ratio of the pumps. Hydraulics International liquid pumps operate at a drive air pressure of 12-150 psi 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. As resistance increases in the system, creating backpressure to the pump,, the pump will decrease its reciprocating action. Backpressure in the system finally balances with the incoming air drive pressure times the ratio. At this point, the pump will stall and maintain pressure without consuming any energy. If there is further demand on the system for flow, the pump will automatically start cycling again. Air Drive line lubrication not required. Advantages include - 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 as it requires no electrical power 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. Ideal for stop-start applications under full load. Easy to install and operate.