SGT thermal power station valve shut-off valve BJ45HBJ41Y

Thermal 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 six o'clock the media from below the valve into the valve, the operating force required to overcome the resistance, is the stem and packing friction thrust by the pressure generated by the media, close the valve of the force is greater than the force to open the valve, so the valve The larger the diameter of the rod, or 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 the heat is turned off valve, 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. Types of liquefied gas cutoff valve stem threads are divided by location external thread type, thread type. According to the flow of media points, straight-through, DC type and angle type. Cut-off valve according to the sealing form points, shut-off valve packing and bellows sealed stop valves. Installation and maintenance should note the following: hand wheel, lever operated bellows globe valve can be mounted in any position on the pipeline. Hand wheels, handles and Wei actuating mechanism for lifting are not allowed to use. The flow of media should be consistent with the direction of the arrow body. Insulation valve, also known as stop-gates, is the most widely used of a valve, the reason it's popular is due to the opening and closing process between the sealing surface friction is small, more durable, opening height is not easy to manufacture, easy maintenance, not only for low-voltage, and suitable for high pressure. Its closure principle is to rely on the valve lever pressure on the valve sealing surface and the seat sealing surface snug fit to prevent the media circulation. Medium heat shut-off valve can only unidirectional flow, directional installation. Its structure is greater than the length of the valve, and fluid resistance, long-term operation, the sealing reliability is not strong. Thermal cut-off valve is divided into three categories: straight, right angle and DC-type oblique valve. When the heat is turned off valve, 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.