For valves connected by flanges, good insulation includes insulation of the whole flange and bolts. After overall insulation, the temperature of all parts (valve body, flange, bolts, etc.) of the valve is basically the same during operation. However, for the exposed valve, the temperature of the flange is higher than the bolt temperature during operation, and the expansion of the flange in the axial direction is greater than the expansion of the bolt, which causes an additional temperature stress on the axial direction of the bolt. The superposition of this temperature stress and the tensile stress generated when the bolt itself is tightened may cause the creep and yield of the bolt. When stopping, the bolt cannot return to its original length after the temperature decreases, so it will become loose, and it is easy to leak when starting again.

Why is the net sleeve of stainless steel pneumatic butterfly valve damaged?
The net sleeve of stainless steel pneumatic butterfly valve is an important part of the hose, which can effectively maintain the hose and extend its service life. If the net sleeve of the stainless steel pneumatic butterfly valve is damaged, it will directly affect the service time of the hose. As for the cause of the damage and how to prevent the hose from being damaged, today I have summarized it for your reference.
1. The net sleeve is pulled off due to faulty welding
Due to the factors of welding quality, the corrugated pipe, ring and wire mesh sleeve form faulty welding of some wires during the trinity welding process (over burning or final welding). In this way, after the hose is installed in the pipeline, due to the uneven stress on the steel wire, under the effect of the medium pressure, the steel wire at the faulty weld will pull off first, so that the entire wire mesh sleeve will pull off, which will lead to the failure of the bellows drum and the risk of occurrence. In order to eradicate this situation, the welding quality should be improved. Before the hose leaves the factory, the water pressure and air tightness test should be stopped, and the hose can leave the factory only after it is qualified.
2. The mesh sleeve is pulled off due to improper device
During the installation of stainless steel pneumatic butterfly valve, the hose will be stretched and twisted due to improper installation or high pressure. When the stress generated by stretching or twisting exceeds the ultimate strength of the hose wire mesh sleeve, the mesh sleeve at the trinity welding part of the hose or other parts of the mesh sleeve will be pulled off, and then the bellows drum will be stretched and damaged, causing medium leakage Therefore, it is required that the design and model selection should be accurate, and the device should be correct.
Since the mesh sleeve is so important to the stainless steel pneumatic butterfly valve, we should pay attention to the welding quality of the hose before purchasing, and pay attention to the correct steps of the device in the process of use. Do not damage the mesh sleeve of the stainless steel pneumatic butterfly valve, which is good for the use of the stainless steel pneumatic butterfly valve connector device