Oberdorfer bronze straight centrifugal & self priming pumps for marine air conditioning and refrigeration. Macerator, single phase, close-coupled, bronze, self priming, rubber impeller pump. Designed for pumping sewage from boats to holding tanks or sewer connections. Close coupled, self priming, all bronze gear pumps with carbon bearings, lip seal & relief valve. Ideal for dockside quick oil change or for engine room use.