Eaton's model 52 duplex basket strainer features a butterfly valve diversion design. Two synchornized butterfly valves are used to switch flow from one chamber to the other. This allows for continuous up-time and very low pressure loss during chamber switch. Other features include quick open covers and convoluted baskets for maximizing straining area. Part number ST052100AF40C is a 10 inch cast iron model 52 with flat face flanged connection points. Additional options available.