Automated, air-operated bellows pumps for groundwater sampling and other applications

Abstract

An air-operated pump for groundwater sampling features a corrugated bellows as opposed to the traditional bladder used for fluid collection. The preferred embodiment includes an air-supply line and a fluid-discharge line, each coupled to the pump body through a controller disposed at an appropriate above-ground location. The bellows is operable 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. An apparatus disposed within the pump body governs the air received through the air-supply line to, at least, semi-automatically cycling the bellows between the refill and the discharge states. To assist in cycling, the pump may further include one or more magnets for latching the bellows in the refill or discharge state, and an electrical sensor for detecting whether or not the bellows is latched. As an alternative, the apparatus for governing the air received through the air-supply line may include a valve in the air-supply line which is mechanically coupled to the bellows. A separate exhaust line may also be provided to expel air received through the air-supply line, in which case the apparatus for governing the air received through the air-supply line also governs the air expelled through the exhaust line.