The AODD pumps feature the design parameters necessary for pumping larger solids that are found in the mining industry. The pumps are available in two models, a 51mm (2-inch) pump and a 76mm (3-inch) pump. What sets these pumps apart from competitive models is the presence of flap-valve technology, rather than the more traditional ball-valve technology, which allows odd-shaped large solids to pass through the wetted path. The pumps also have a bolted configuration, which ensures total product containment, while a redesigned liquid path reduces internal friction to maximize output and efficiency. The pumps feature the manufacturer’s patent-pending air distribution system (ADS) that greatly improves the performance characteristics of air-operated, double-diaphragm pumps. This air distribution system incorporates three moving parts: The unbalanced air valve spool, the pilot spool, and the main shaft/diaphragm assembly. The ADS results in maximum reliability, lower operational costs and superior flow rates.