The automatic drain valve will empty its sump whenever the reservoir air pressure drops. The sump will stay open until the sump pressure drops enough to allow the exhaust valve to close. The length of time that the exhaust valve stays open will depend on the amount of pressure change in the reservoir. The automatic drain valve can also be manually operated by using a tool to push the pin in the bottom center of the valve upward. Since 1972, Tectran has been a leading designer and manufacturer of high-performance tractor and trailer connection systems based in Buffalo, New York. The company is highly recognized for its range of AirPower hook-up lines, which come with revolutionary features such as kink-resistant tapered grips and rust-resistant brass construction. The company also offers a one-stop shop for line clamps, fittings, plugs and sockets, air tanks, junction boxes, trailer brackets, and other related parts and accessories. Tectran products are designed for the latest and older models of trucks, trailers, and buses, and they can withstand the most demanding applications. Each product is also built, assembled, and tested in-house to ensure safety and optimum performance.