In addition to the advantages of elastic seat sealing valve, XXZ41 fire special signal elastic seat sealing gate valve is often used in automatic sprinkler fire pipeline system to critically control the water supply pipeline and can indicate the valve opening remotely. Rising rod gate valve and attached opening indication gate valve are also often used in fire protection systems, if the gate valve installation position is high from the ground, generally use the rising rod gate valve, can clearly indicate the gate valve opening, if the installation position is low. Then a gate valve with an opening indicator is required.