Forums > General Discussion > What are the characteristics of gate valve? What parts are there?
| What are the characteristics of gate valve? What parts are there? | |
|---|---|
| Posted: 01 Aug 2022 05:12 UTC | Post #1 |
| Kaiwen Deck & Engine |
Registered Total Posts: 6 |
| Characteristics of gate valve ①The advantages of gate valve a. The fluid resistance is small. Because the medium channel inside the gate valve body is straight, the flow direction of the medium does not change when it flows through the gate valve, so the fluid resistance is small. b. The opening and closing resistance is small. Because the gate movement direction is perpendicular to the medium flow direction when the gate valve is opened and closed, compared with the globe valve, the opening and closing of the gate valve is more labor-saving. c. The flow direction of the medium is not restricted. The medium can flow in any direction from both sides of the gate valve, which can achieve the purpose of use, and is more suitable for pipelines where the flow direction of the medium may change. d. The structure length is shorter. Because the gate of the gate valve is placed vertically in the valve body, and the disc of the globe valve is placed in the valve body horizontally, the structural length is shorter than that of the globe valve. e. Good sealing performance. When fully open, the sealing surface of the gate valve is less eroded. Gate valve ② Disadvantages of gate valve a. The sealing surface is easily damaged. When opening and closing, there is relative friction between the two sealing surfaces in contact with the valve seat, which is easy to be damaged and affects the sealing performance and service life. b. The opening and closing time is long and the height is large. Since the gate valve must be fully opened or fully closed when opening and closing, the gate travel is large, a certain space is required for opening, and the overall size is high. c. The structure is complex. There are many parts, it is more difficult to manufacture and maintain, and the cost is higher than that of the globe valve. The structure of the gate valve A gate valve is mainly composed of the valve body, valve cover or bracket, valve stem, valve stem nut, gate plate, valve seat, stuffing box, sealing packing, packing gland, and transmission device. ①The valve body is the main body of the gate valve, which is directly connected with the pipeline or (equipment) and constitutes the pressure-bearing part of the medium flow channel. It is an important part of installing the valve cover, placing the valve seat, and connecting the pipeline. The valve body needs to accommodate the disc-shaped gate plate that is vertical and moves up and down, so the cavity height of the valve body is relatively large. The shape of the valve body section mainly depends on the nominal pressure. For example, the low-pressure gate valve body can be designed to be flat to reduce its structural length; Its pressure bearing capacity reduces wall thickness. The medium passages in the gate valve body are mostly circular sections. For gate valves with larger diameters, in order to reduce the size, opening and closing force, and torque of the gate, the form of constriction can also be used. After the constriction is adopted, the gate valve will be increased. The internal fluid resistance, pressure drop, and energy consumption increase, so the channel contraction ratio should not be too large. Usually, the ratio of the diameter of the gate valve seat channel to the nominal diameter is 0.8 to 0.95, and the inclination angle of the busbar of the reduced channel to the center line is not more than 12°. The structure of the gate valve body determines the connection between the valve body and the pipeline, and the valve body and the valve cover. The valve body blank can be cast, forged, forged welded, cast welded and tube sheet welded. Gate valve casting body is generally used for diameter ≥ DN50, gate valve forging body is generally used for diameter ≤ DN50, forged welded valve body is used for valves that have difficulties in the overall forging process and is used on important occasions, gate valves Gate valve cast-welded valves are used for those that cannot meet the requirements of integral casting, and cast-welded structures can be used. ②The valve cover is connected with the valve body and forms the main pressure-bearing part of the pressure chamber with the valve body, and there is a stuffing box on it. For medium and small diameter valves, the valve cover is provided with a mechanism for supporting parts such as the stem nut or the transmission device. ③Bracke t It is connected with the valve cover and is used to support the valve stem nut or the parts of the transmission device. Gate valve：https://www. kwvalvescontrol.com/ Gate-Valves | |
1 / 1