Medium carbon steel casting off valve J41H-16C

Cut-off valve opening and closing parts of the plug-shaped valve, leaving it flat or cone seal, valve seat along the center line of a straight line. Stem form of exercise, (generic name: dark bar), but also lift rotating rod, (generic name: the next shot) cut-off valve is closed parts (valve) moves along the centerline of the valve seat. According to this mobile form of valve and valve seat port change is associated with the valve stroke is proportional. As such the valve stem to open or close the relatively short trip, but also have very reliable cutting function, but also because the trip is proportional change in the seat and the valve port valve is very suitable for flow regulation. Therefore, this type of valve is suitable for cut or regulation and throttle use. Cut-off valve is mandatory sealed valve, so when the valve is closed, pressure must be applied to the valve to force the sealing surface does not leak. When the medium enters the valve from the underside of the disc, the operating force needed to overcome the resistance, the frictional force by the thrust generated by the pressure medium and the valve stem packing, close the valve opening force larger than the force of the valve, so that the stem The diameter should be large, otherwise the stem benders failures occur. In recent years, from the emergence of self-sealing valve, the medium flow shut-off valve on the change into the valve chamber from above the valve, then at medium pressure, a small off valve force, and force open the valve, the valve stem diameter can be reduced accordingly. Meanwhile, in the role of the media, this form of valve is also relatively tight. China's valve "three to" has been provided, closing the flow valve, should be top-down. When this valve is to be installed horizontally off valve is open, the valve opening height, the nominal diameter of 25% to 30%, the flow has reached the maximum, that valve has reached the fully open position. So off fully open position of the valve, the valve stroke should be determined.