The flat gate valve is a sliding valve whose closing part is a parallel gate. The closing part can be a single gate disc or a double gate disc with a supporting mechanism between them. The pressing force of the wedge to the valve seat is controlled by the medium pressure acting on the floating wedge or floating valve seat. If it is a double wedge flat gate valve, the support mechanism between the two wedges can supplement this pressing force.

Features of flat gate valve:

1. The valve seat adopts O-ring seal and floating valve seat structure with preload, so that the inlet and outlet of flat gate valve are sealed in both directions. The opening and closing torque is only 1/2 of ordinary valves;

2. When fully open, the channel is smooth and straight, the flow resistance coefficient is very small, there is no pressure loss, simple cleaning;

3. The packing structure with self sealing ability is adopted, the sealing performance is more reliable than ordinary graphite packing. In addition, grease is injected into the sealing surface of the packing, the sealing surface meets the zero leakage standard;

4. When the flat gate valve is closed, it can automatically remove the high pressure in the inner cavity to ensure the safety of use;

5. Fully enclosed structure, good protection performance.

Flat gate valve is divided into single gate plate and double gate plate. According to the connection mode, it can be divided into butt welded flat gate valve and flange flat gate valve.

Features of butt welded flat gate valve:

1. Small fluid resistance and small scouring and erosion of sealing surface by medium;

2. Opening and closing is labor-saving;

3. The flow direction of the medium is unrestricted, no turbulence and no pressure reduction.

4. Simple shape, short structure length, good manufacturing technology and wide application range.

Flange flat gate valve is stable and reliable when used in pipeline, Therefore, DERVOS recommends that flange flat gate valve could be used in high pressure pipeline.

Features of flange type flat gate valve:

1. The sealing structure of flange flat gate valve is elastic with preload, and the upstream and downstream sealing seats are sealed at the same time. There is always face-to-face seal between the valve seat and the seal;

2. The valve seat has self-cleaning function and is not directly scoured by the air flow during the opening or closing of the valve. The valve seat is made of lubricated and non abrasive materials;

3. The problem of the valve actuator will not affect other parts of the valve, and the maintenance and replacement can be carried out without removing the valve;

4. When the flange flat gate valve is fully opened, the channel is smooth and straight, the flow resistance coefficient is very small, there is no pressure loss, and the pipeline can be cleaned by wool ball.