The characteristics of national standard gate valve
1, the opening and closing moment is small because the gate valve when it is opened and closed, the movement direction of the gate plate is perpendicular to the flow direction of the medium. Compared with the globe valve, the opening and closing of the gate valve is less effort.
2, the fluid resistance is small because the medium channel in the gate valve body is straight through, the medium does not change the flow direction when flowing through the gate valve, so the fluid resistance is small.
3, the length of the structure is shorter because the gate valve is vertically placed in the valve body, and the globe valve disc is horizontally placed in the valve body, so the length of the structure is shorter than the globe valve.
4, the medium flow direction is not limited medium can flow from both sides of the gate valve in any direction, can achieve the purpose of use. More suitable for the flow direction of the medium may change in the pipeline.
5, good sealing performance when fully open sealing surface by less erosion.
6, long idle time, high height because the gate valve must be fully open or fully closed when opening and closing, the gate travel is large, open with a certain space, high size.
7. When the sealing surface is easy to be damaged, there is relative friction between the two seals in contact with the gate plate and the valve seat, which is easy to be damaged and affects the sealing parts’ ability and service life.
8, complex structure more parts, manufacturing and maintenance is more difficult, the cost is higher than the stop valve.
The gate valve has the characteristics of small fluid resistance, wide applicable pressure and temperature range, etc. It is one of the most commonly used cut-off valves, used to cut off or connect the medium in the pipeline. In full open when the whole flow through, the medium running at this time the pressure loss is minimal. Gate valves are usually used without the need for frequent opening and closing, and keep the gate fully open or fully closed. Not intended for use as a regulator or throttle. For high speed flow media, the gate vibration can be caused when the gate is partially opened, and the vibration may damage the sealing surface of the gate and valve seat, and the throttling will cause the gate to be eroded by the media.
Cast iron gate valves are commonly used in China, and there are many serious problems such as freezing crack of valve body and sluice falling off. The carbon steel stem of cast iron gate valves is easy to rust, the quality of packing gasket is poor, and the leakage inside and outside is serious. The PN1.0MPa low pressure carbon steel gate valve of valve net replaces the traditional iron gate valve, and effectively solves the problems such as the shell of cast iron gate valve is easy to freeze and crack, the gate plate is easy to fall off, the valve stem is easy to rust, and the sealing performance is not reliable.
Post time: Mar-24-2021