Elevator Guide Rail Machine The production line has the characteristics of high precision, production speed of more than 4 times of the traditional production line, and can produce different shapes of air rail products according to the drawings. The company is striving to become the most competitive enterprise in China's welded pipe unit and cold bending unit industry with the tenet of [leading technology, reliable quality and high quality service". The products of Elevator Guide Rail Machine are mainly sold to more than 20 provinces and cities in China, and exported to Australia, Middle East, North America, Southeast Asia and Africa.
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Control valve in the chemical industry in fire protection troubleshooting
Valve Leakage: Under the normal working pressure of the equipment, the valve flap and valve seat sealing surface occur more than the allowable degree of leakage. The leakage of the regulating valve will not only cause the loss of the medium. In addition, the continuous leakage of media will make the hard sealing material is damaged, but the sealing surface of the commonly used control valve is a metal material on the metal material, although strive to be smooth and smooth, but in the case of media pressure To the absolute leak is also very difficult. Therefore, the valve is flammable or flammable or medium, at the specified pressure value, if the use of professional testing tools test, such as to the extent permitted by the standard, can be considered sealing performance is acceptable. Common causes of valve leakage mainly in the following three conditions: First, debris falls on the sealing surface, the sealing surface padding, resulting in a gap between the valve core and the valve seat, so the valve leakage. To eliminate this failure is to remove debris falling to the sealing surface, usually in the pressure vessel to prepare the size of the repair, the first to do pressure vessel safety gate running test and found that leakage, the pressure vessel to stop working and the valve overhaul, Wash the sealing surface. Second, sealing surface damage. Seal surface damage caused by the following main reasons: First, poor sealing surface material. Due to years of use, valve core and seat sealing surface has generally been studied very low, so that the sealing surface hardness is greatly reduced, resulting in reduced sealing performance, the best way to eliminate this phenomenon is the original sealing surface turning Go down, and then re-welding the drawings required processing to improve the sealing surface hardness. Note that in the processing must ensure the quality of processing, such as the sealing surface cracks, trachoma and other defects must be machined back after processing. Newly processed valve seat must meet the drawing requirements. Second, the poor quality of maintenance, valve seat grinding can not meet the quality standards, the way to eliminate this failure is based on the degree of injury using grinding or turning grinding method to repair the sealing surface or reinstall the new control valve. Third, another cause of leakage caused by the control valve is due to improper assembly or parts size is not appropriate. In the assembly process, the valve seat is not fully aligned or the surface with light transmission phenomenon, or the valve seat sealing surface is too wide, which is not conducive to sealing. Elimination method is to check the spool around the size and uniformity of the gap to ensure that the valve core tip hole and the sealing surface with a positive, check the Ministry of the gap does not allow lift valve, according to the drawing requirements to reduce the width of the sealing surface to achieve effective sealing . Fourth, spool, seat deformation leak. Valve core, seat leakage is mainly due to the production process of valve casting or forging defects can lead to enhanced corrosion. The corrosive medium through the erosion of the fluid medium can also cause the regulator valve leakage. Corrosion mainly exists in the form of erosion or cavitation. When the corrosive medium passes through the regulating valve, erosion and impact on the valve core and the valve seat material will occur, causing the valve core and the valve seat to become oval or other shapes as The passage of time, leading to spool, seat is not complete, there is clearance, the strict control of leakage. The key to the solution to the valve spool, valve seat and other material selection off, quality control. Select corrosion-resistant materials, pitting, trachoma and other defects of products resolutely removed. If the valve core, seat deformation is not serious, can be fine sandpaper grinding, eliminate traces, improve seal finish, to improve the sealing performance. If the damage is serious, the new valve should be replaced.