What matters should be paid attention to in installation and maintenance of globe valve
Publisher：Botou Valve
The installation and maintenance of globe valve should pay attention to the following matters:
1. Handwheel and handle operated globe valves can be installed in any position of the pipeline.
2. Handwheels, handles and large-scale mechanisms are not allowed to be lifted.
3. The flow direction of the medium should be the same as the arrow direction shown by the valve body. The purpose of globe valves Globe valves refer to valves whose closures (discs) move along the center line of the seat.
According to the movement of the disc, the change of the seat opening is proportional to the disc travel. Because the stem opening or closing stroke of this kind of valve is relatively short, and has a very reliable cut-off function, and because the change of the seat opening is proportional to the disc travel, it is very suitable for flow regulation. Therefore, this type of valve is very suitable for cutting or regulating and throttling.
Butterfly check valve
Once the valve disc of globe valve is removed from the closed position, there is no contact between the seat and the sealing surface of the valve disc, so the mechanical wear of the sealing surface is very small, so its sealing performance is very good. The disadvantage is that the particles in the flowing medium may be trapped between the sealing surfaces. However, if the disc is made into steel ball or ceramic ball, the problem will be solved. Because the seat and disc of most globe valves are easy to repair or replace, and there is no need to remove the entire valve from the pipeline when repairing or replacing the sealing elements, this is very suitable for the occasion where the valve and pipeline are welded together. The minimum flow resistance of globe valves is also higher than that of most other types of valves due to the change of flow direction when the medium passes through such valves. However, according to the structure of the valve body and the layout of the stem relative to the inlet and outlet passages, this situation can be improved. At the same time, because of the small travel between the opening and closing of the globe disc and the sealing surface can withstand multiple opening and closing, it is very suitable for occasions requiring frequent switching. Globe valves can be used in most media flow systems. Various forms of globe valves have been developed to meet various applications in petrochemical, power, metallurgical, urban construction, chemical and other sectors. Globe valves are widely used, but due to the large opening and closing moment and the long structure length, the nominal diameter is usually limited to less than 250 mm, but also to 400 mm, but special attention should be paid to the direction of import and export when selecting. Generally, the medium of cut-off valve below 15Omm mostly flows from the lower part of the valve disc, while the medium of cut-off valve above 20mm mostly flows from the upper part of the valve disc. This is due to the closing moment of the valve. In order to reduce the opening or closing moment, generally more than 20 mm globe valves are equipped with internal or external bypass valves.
