Low temperature stainless steel globe valve stem seal At present, there are two kinds of stuffing box and bellows seal on the valve stem of the low temperature stainless steel globe valve. Among them, the valve on the mass production air separation device adopts the stuffing box sealing structure mostly. In toxic and flammable explosive gas medium valve, stem can be sealed with a wave tube, but in the high pressure gas greater than or equal to 80MPa, bellows can not withstand such high external pressure, only use stuffing box sealing stuffing box Sealing due to simple manufacturing and processing, maintenance and replacement easy to use in the actual production is quite common. However, in order to ensure the packing density, its working temperature generally can not be lower than -40 ℃, which requires low-temperature valve packing work on the device should be as close to ambient temperature work. Under normal circumstances, the filler does not frost that is in a positive working condition, but if the filler itself or the working life of the original so that the filler is not sealed, then the low temperature gas through the filler will cause leakage and stuffing box freeze frost, and Will result in further leakage of filler failure. In the field of aerospace applications, many low-temperature valve series, due to the reasons for most of the stuffing box sealed structure, and in order to ensure the temperature of the stem stuffing box, lengthen the length of the stem are used, resulting in the size of these cryogenic valves bigger. Low-temperature stainless steel globe valve is used for medium not to allow micro-leaks and unfilled packing occasions. In the bellows design, its life is the key bellows life expectancy and its size and the initial installation of the state. Corrugated pipe to ensure the life of the valve, in the case of a certain stroke, the installation of corrugated to ensure that they do not withstand the role of additional external force; in the working state of the bellows is subjected to external pressure, the working condition is good, but by Rapid closure of cryogenic valves or cavitation in pipes may cause water hammer. Therefore, the bellows to withstand the calculated pressure, to add a predetermined safety factor, and as far as possible so that the bellows to withstand direct water hammer. Hydraulic Retarder,Truck Hydraulic Retarder,Truck Braking Retarder,Heave Truck Hydraulic Retarder Fuxin Dare Automotive Parts Co., Ltd. (DARE AUTO) , https://www.fuxindareauto.com
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