A Sprague hydraulic air driven pump is a kind of pump that operates pneumatically. It is considered an ideal source of power for a variety of frame, body and alignment applications, and can be used with shop presses or ram kits. The air-driven machine comes with an adapter and air nipple for ease of use.
The Air Drive Section of a Pump
The Sprague hydraulic air driven pump features two main sections: the air drive section and the hydraulic section. The air drive section usually comes standard with a piston that is light in weight and which consists of a seal placed inside an aluminum barrel. The size of the piston is the same for all air-driven pumps in an established series. The drive air forces a piston down on the pressure or compression stroke, then forces the piston up on a suction stroke.
The Hydraulic Section
The hydraulic section of the assembly features a hydraulic piston/plunger that is affixed to an air piston. The bottom section is contained within the pump head. The size determines the pressure ratio of a Sprague hydraulic air driven pump, which then designates the optimum pressure capacity. The purpose of the hydraulic section is to pull liquid into the hydraulic body via an inlet check valve and force it out via an outlet check valve at an increased pressure.
The check valves are designed to direct the passage of the liquid through the air-driven pump. During the suction stroke of the piston/plunger, the inlet check valve opens maximally. The liquid is then drawn into the pump, while a spring and differential pressure hold the outlet check valve shut. On the pressure stroke, the piston/plunger directs liquid from the outlet check valve, while the inlet check valve is shut.
This type of design features a seal that is positioned around the piston/plunger of the device. The purpose of the seal is to hold the pressurized liquid during the cycling phase, to prevent external leaks and leaks inside the air drive. A variety of seal designs and products are used, based on the liquid that is pumped, the pressure rating and the operational temperature.
