Electric gate valve consists of stem, valve body, bonnet, gate, drive and other parts (fasteners, stem nut, sealing packing). Rod (torsion shaft), gate valve is thus divided into two types: open rod gate valve and dark rod gate valve.
1. Rising stem gate valve.
The handwheel (or another drive) is stationary on the valve stem nut. When the handwheel (or another drive) shifts and turns the valve stem nut to twist, the valve stem moves in a concave and convex manner, thereby enabling the gate valve to move up and down to open and close the pipeline. When the rising stem gate valve is closed, the valve stem protrudes from the top of the handwheel, which probably directly shows the closing level of the electric gate valve. The trapezoidal rib of the valve stem is on the upper half of the valve stem, which is not directly arranged by the medium, is not corroded by the medium, and is smooth. Therefore, it is suitable for the electric gate valve of corrosive medium, dirty medium and high temperature steam medium. The opening and closing level of the valve can be seen directly from the rib, which is also one of its advantages to be easy to dominate. The disadvantage is that because the rib leaks out, it is easy to stick to the dust in the air and accelerate the wear of the rib, so it should only be placed indoors. Even so, monopolies are more common.
2. Dark stem gate valve.
The handwheel (or another drive) is stationary on the valve stem, and the valve stem rib is stationary on the top of the gate. When the handwheel (or another drive) transitions, the electric gate valve rib starts the gate for ups and downs. The valve stem can only do torsional flow. The advantage is that the valve stem does not lift high when closed, and requires less space for placement. Therefore, it is often used as a large channel gate valve, or where the installation space is limited. Because the valve stem does not move up and down, it cannot display the closed level through the extension length of the valve stem like a rising stem gate valve, so an opening pilot should be installed.