The Schroeder Industries Duplex Cast Basket Strainer is a simple, economical, and trouble free design that has been time tested in applications around the world over many years. This type of strainer is actually a high quality, pressure rated plug valve with integral straining baskets. Switching the flow from one basket to the other is accomplished by moving the operating handle through a 90 degree arc. The design is such that it is impossible for this operation to stop the flow because of the unique port design in the diverter plug. The entire switching operation takes less than 30 seconds. No tools are needed. The plug is automatically positioned each time in exactly the right spot by integral stops.