Gate valves are designed for fully open or fully closed service. They are installed in pipelines as isolating valves, and should not be used as control or regulating valves. Operation of a gate valve is performed doing an either clockwise to close (CTC) or clockwise to open (CTO) rotating motion of the stem. When operating the valve stem, the gate moves up- or downwards on the threaded part of the stem.
Gate valves are often used when minimum pressure loss and a free bore is needed. When fully open, a typical gate valve has no obstruction in the flow path resulting in a very low pressure loss, and this design makes it possible to use a pipe-cleaning pig. A gate valve is a multiturn valve meaning that the operation of the valve is done by means of a threaded stem. As the valve has to turn multiple times to go from open to closed position, the slow operation also prevents water hammer effects.
Gate valves can be used for a vast number of fluids. Bundor's gate valves are suitable under the following working conditions:Potable water, wastewater and neutral liquids: temperature between -20 and +70 °C, maximum 5 m/s flow velocity and up to 16 bar differential pressure.
Gas: temperature between -20 and +60 °C, maximum 20 m/s flow velocity and up to 16 bar differential pressure.
Our gate valves has two design of Rising stems and Non-rising stems
Rising stems are fixed to the gate and they rise and lower together as the valve is operated, providing a visual indication of the valve position and making it possible to grease the stem. A nut rotates around the threaded stem and moves it. This type is only suitable for above ground installation.
Non-rising stems are threaded into the gate, and rotate with the wedge rising and lowering inside the valve. They take up less vertical space since the stem is kept within the valve body. Weisidun offers gate valves with a factory-mounted indicator on the upper end of the stem to indicate the valve position.
Gate valves with non-rising stems are suitable for both above ground and underground installations.
