Globe Valve manufacturing and maintenance are more convenient
Nov 29, 2017
Globe Valve refers to the opening and closing parts are plug-shaped disc, sealing surface was flat or cone, the valve flap along the center line of the fluid for linear movement of the valve. The movement of the stem, there are lifting rod (stem lift, hand wheel does not lift), there are lifting and rotating rod (hand wheel and stem together with the lift, the nut is located on the valve body). The cut-off valve is only fully open and fully closed, and is not allowed to be adjusted and throttled.
The stop valve is a forced seal valve, so when the valve is closed, pressure must be applied to the valve to force the sealing surface from leakage. When the medium from the bottom of the valve into the valve, the operating force to overcome the resistance is the stem and packing friction and pressure generated by the pressure of the valve, close the valve force than the valve, so the stem Of the diameter to be large, otherwise there will be stem stem bending failure. In recent years, from the self-sealing valve appears, the valve flow of the valve will be changed from the top of the valve into the valve chamber, then under the action of the media pressure, the valve is small, and open the valve force, The diameter can be reduced accordingly. At the same time, in the role of the media, this form of the valve is also more tight. China's valve "three to" has been provided, the flow of the valve, all from top to bottom.
When the valve is opened, the opening height of the valve is 25% ~ 30% of the nominal diameter, the flow has reached the maximum, indicating that the valve has reached the full position. So the full stop position of the cut-off valve should be determined by the stroke of the valve.
According to this movement of the valve flap, the change of the valve seat is proportional to the valve stroke. As the valve stem valve opening or closing stroke is relatively short, and has a very reliable cutting function, but also because the valve seat and the valve seat is proportional to the stroke, is very suitable for the regulation of the flow. Therefore, the valve type valve is very suitable for cutting or adjustment and throttling use.