Cryogenic valve is prone to stuck stuck cause

Why is the phenomenon of low-temperature valve stuck stuck can not move, how to solve? A: The low temperature valve installed at room temperature, low temperature work, a wide range of temperature changes. If the design, installation is not easy to generate thermal stress or deformation. At the same time, the operating part of the valve is at room temperature, the circulation part is at a low temperature. In order to reduce the cold loss, the stem often do very long, it is easy to produce deformation and stuck. Cryogenic valves are often flexible at room temperature, low temperature is very tight, not even open. Valve stuck at low temperatures are the main reasons: 1, the installation, the valve and pipe configuration unreasonable and prestressed; or pipe cold compensation capacity is poor, low temperature valve position change; or lack of valve stent, deformation occurs at low temperatures; Or improperly fixed valve, cold box at low temperature deformation and affect the stem and valve body concentricity. 2, in design, due to the different material of the stem and the valve sleeve, linear expansion coefficient is different. General valve stem with stainless steel, linear expansion coefficient of 1.73 × 10-6 ℃ -1; valve sleeve is brass, the linear expansion coefficient of 19.9 × 10-6 ℃ -1, brass shrinkage than stainless steel, low temperature may Biting the thread. Especially when using the dark rod structure and fine thread, the threaded buckle temperature range, thread gap is small, more prone to biting phenomenon. 3, in operation, due to incomplete heating of the valve, or valve packing at the water, causing freezing at low temperatures, or the valve closed at room temperature too tight, so that the wire bites and so on. In order to prevent the phenomenon of valve stuck in the design should adopt the rod structure and coarse thread trapezoidal thread; in the installation should have a solid valve at the bracket to prevent the valve displacement with the valve will be bent. The valve and the cold box can be fixed by elastic connection to prevent valve stem deformation and the valve body is not in the heart; naked cooling period, to check and adjust the valve installed in the cold state, when the valve is found to be stuck after cooling phenomenon , Adjustable valve in the cylinder shell fixed flange, so that the switch freely. In operation, before the start of the heating should be thorough, the valve is closed to the principle of airtight, do not force too much. This keyword search: Yongnian Inoteco Valve Co., Ltd. more valve supply