Cast iron gate valves are designed for circular and square outlets with unidirectional water flow. They feature a tight structure and reliable operation, requiring no manual operation as the opening and closing force is derived from the water pressure source. The gate opens when the water pressure inside the cast iron gate exceeds the external pressure, and closes otherwise. The cast iron gate valve consists of four parts: valve seat, valve plate, sealing gasket, and hinge. It is suitable for water conservancy systems, municipal sewage, urban flood prevention and drainage, wastewater treatment plants, and waterworks. The gate valves are available in two types: circular and square, and can be customized according to the size and shape of the outlet.