Product Overview Signal gate valves and signal butterfly valves are often used in automatic sprinkler fire protection pipeline systems to monitor the water supply pipeline and can remotely indicate the valve opening. Rising stem gate valves and gate valves with opening indication are also often used in fire protection systems. If the gate valve is installed at a higher position from the ground, a rising stem gate valve is generally used, which can clearly indicate the gate opening. If the installation position is lower, a gate valve with opening indication is required.