The model AL is a cast, gate valve duplex strainer offering bank vault construction and quality. Designed for longevity, the model AL has only one set of moving parts—the gate valves. These sliding valves have wedge seating, meaning they are wedged to the body when in the closed position. Therefore, the valves do not come in contact with the body during the chamber change over process, virtually eliminating wear. The body walls are the thickest in the industry, providing decades of service. Easy operating features include quick opening covers, cover-lifting davits, and interlocking chain drive on the valve hand wheels, allowing both valves to operate with the turn of one hand wheel. And with the lowest pressure drop available, it becomes the least expensive strainer to operate. The outstanding longevity of the model AL plus its low operating expenses com bine to give you a strainer with the lowest life cycle cost available.