The Double Disc Pump from Penn Valley Pump Co. does not rely on close tolerances within the pump chamber to generate flow, eliminating friction. It can run dry indefinitely without damage, and the short stroke allows the pump to incorporate a non-leak sealing trunnion that requires no maintenance, seal water, packing or lubrication. It is self-priming and can pass up to 2-inch solids and line-size semisolids. 215/343-8750; www.pennvalleypump.com.
