The Slab gate valves is a sliding valve with closing parts as parallel gates. The shutter can be single gate or double gate with extension mechanism. The pressing force of the gate to the valve seat is controlled by the medium pressure of the floating gate or floating seat. If it is a double gate flat gate valve, the expansion mechanism between the two gates can supplement this compaction force.The flat gate valves can be divided into manual flat gate valves, pneumatic flat gate valves and electric flat gate valves according to the driving mode. It can be divided into flat gate valve with diversion hole, flat gate valve without diversion hole, flat gate valve of oil field, flat gate valve of pipeline and gas plate valve.