Air-operated pumps with removable cartridges for groundwater sampling and other applications

Abstract

A pump of the type used for groundwater sampling, including the removal of gasoline or other hazardous materials, utilizes a cartridge which, in the preferred embodiment, is easily removable for bailing and other operations. The cartridge may be in the form of a flexible-walled bottle or other device, including a corrugated bellows, thereby providing a number of advantages over conventional designs, including the potential for truly automatic operation and higher throughput. The open end of the bellows or other collection device according to the invention is also preferably positioned with the open end oriented upwardly during normal operation, thereby allowing trapped gas to escape. Air-supply and fluid-discharge lines are coupled to the pump body through a pump head from an above-ground location. If removable, the bellows or other fluid collection device is fastened to the pump head within a shell which is removably attached to the pump head. The fluid-collection cartridge may be connected to the pump head through a threaded fitting, a press fitting, or other means providing an appropriate seal to the surrounding environment. In any case, cartridge is operable through pressurization be the air-supply line between a refill state, wherein fluid is drawn into the pump body through the fluid inlet, and a discharge state wherein fluid is forced out of the pump body through the discharge line.