Gate Valve Series

Description:
Gate valve is a slide gate that equips with parallel slide valve as closure member. The slide gate moves along the parallel axis in vertical direction. The closure member is single board or double disc with shoving force. Pressing force between the gate segment and is measured by the pressure from floating gate segment or the medium of the valve seat. The shoving force of double disc flat gate valves will replenish the pressing force.Gate valve is various in structures. There is flat gate valve, wedge gate valve, lifting rod type, rotary rod type depending on the potted component used. The flat gate valve and wedge gate valve are common. There are lifting rod (rising stem) gate valve and rotary rod (non-rising stem) gate valve according the valve stem structure.
Gate valve has the advantages of small flow resistance. The flow resistance of the riser is close to that of short straight pipe. Flat gate valve with diversion hole is installed in pipelines. It can be cleaned directly by the pipe cleaner. The flat gate valve fluid is applicable for particles for the gate segment slides on the surface of the two valve seats. The seal face of the flat gate valve is automatic positioning and free from thermal deformation. Even the valve is closed due to the cold condition; the thermal extension of the valve rod won't overload the seal surface. The motor-driven flat valve can be used to control opening and closing position.
But when medium pressure is low, the sealing force is unsatisfactory. On the contrary, if the sealing surface is lubricated by the medium, frequent start and stop may generate a heavy surface friction. In addition, the round gate segment moves transversely along the circular runner. Only in the middle of the valve, can the valve measure the flow. The gate segment vibrates strenuously when it flows in high density medium. If the valve seat is made into V shaped port and contact with gate segment directly, it will throttle. 
Gate valve is widely used and cut off as medium in pipeline. Usually, the gate valve is not used to regulate flow. It's suitable to low and high temperature, voltage. It is seldom used in pipeline that delivers granular medium like slurry. Pipe whose aperture is bigger than DN50 is taken as cutting off medium. For small apertures, cast steel gate valve is widely applied.