Low temperature stainless steel by the pneumatic valve pneumatic valve stem seal

low temperature stainless steel by the pneumatic valve pneumatic valve stem seal
the current low temperature stainless steel by the pneumatic valve pneumatic valve stem seal has two kinds of stuffing box and corrugated pipe in batch production of the pneumatic valve in the air separation plant, the pneumatic valve stem with gland seal structure. In toxic flammable and explosive gas medium in the work of the pneumatic valve, pneumatic valve stem wave tube seal can be used, but in high pressure gas is greater than or equal to MPa, the bellows can't bear such a high pressure, can only use gland seal gland seal because of its simple manufacturing process, convenient maintenance replacement is quite common in actual production application. But in order to ensure the packing performance, its working temperature cannot under - general ℃, which requires low temperature work on pneumatic valve packing device should be work under close to environment temperature. Frost that under normal circumstances, the packing is not in the positive work state, but if due to the packing itself or the working life of the original packing is not sealed, the low temperature gas through packing will cause leakage and stuffing box freezing cold cream, and can cause further leakage failure of packing. In space application of pneumatic valve series, many of the stuffing box USES mostly due to a sealing structure, and in order to ensure that the temperature of the pneumatic valve rod stuffing box, adopt the method of extended pneumatic valve stem length, caused by the low temperature of pneumatic valve sizes are relatively large.
low temperature stainless steel by the pneumatic valve leakage is not allowed to trace for medium and discomfort packing more occasions. In the design of corrugated pipe, its life is the key, the life of the corrugated pipe to the stroke size and initial installation state. Guarantee the life of the corrugated pipe cut-off pneumatic valve, the stroke of a certain situation, to ensure the installation corrugated don't bear the role of the additional external force; In the working status because of bellows under external pressure, the working condition is good, but by a pneumatic valve down quickly at low temperature or possible air pockets in the pipe can water diversion. So in the calculation of bellows under pressure, with safety coefficient, and the best corrugated pipe to avoid water hammer under directly.