Treatment of Fire Prevention Problems of Control Valves in Chemical Enterprises

Treatment of fire prevention problems of regulating valves in chemical enterprises. Valve leakage: Under normal working pressure of the equipment, the sealing surface of the valve disc and the valve seat will leak beyond the permitted level. The leakage of the regulating valve will not only cause the loss of the medium. In addition, the continuous leakage of the medium will damage the hard sealing materials. However, the sealing surfaces of the commonly used regulating valves are made of metal materials to metal materials. Although they strive to be bright and flat, they must be under pressure. It is also very difficult to be sure that it does not leak. Therefore, for regulating valves with flammable or flammable media such as mechanical seals, under the regular pressure value, if a professional inspection tool is used for inspection, if it reaches the specified scale, the sealing function can be qualified. Usually, the reasons for valve leakage are mainly the following three conditions: First, the sundries fall on the sealing surface and cushion the sealing surface to form a gap between the valve core and the valve seat, and then the valve leaks. The way to eliminate this problem is to remove the debris that falls on the sealing surface. Usually, when the pressure vessel mechanical seal is prepared for large and small repairs, the first step is to do the pressure vessel safety door run-up test. When the mechanical shaft seal leaks, stop the pressure. The container works and the valve is repaired, and the sealing surface is flushed. The second is damage to the sealing surface. The primary reasons for the damage of the sealing surface are as follows: First, the sealing surface material is poor. Because of years of use, the sealing surface of valve core and valve seat has been researched very low, so that the hardness of the sealing surface is greatly reduced, and then the sealing function is reduced. The best way to eliminate this appearance is to seal the original Turn the surface down, and then re-surfacing according to the drawing requirements to improve the surface hardness of the sealing surface. Note that the processing quality must be ensured during the processing, such as cracks, trachoma and other defects on the sealing surface must be turned down and processed from the beginning. The newly processed valve core and seat must meet the requirements of the drawings. The second is the poor maintenance quality. The grinding of the valve core and seat does not meet the quality specification requirements. The way to eliminate this problem is to choose the method of grinding or grinding after turning to modify the sealing surface or install a new control valve from the beginning according to the degree of damage. Third, another reason for the leakage of the regulating valve is due to improper installation or improper dimensions of related parts. During the installation process, the valve core and valve seat are not completely aligned or the joint surface has a light-transmitting appearance, or the valve core and valve seat sealing surface is too wide, which is not conducive to sealing. The elimination method is to check the size and uniformity of the cooperation gap around the spool, to ensure that the center hole of the spool is the same as the sealing surface, check the gaps and not allow the spool to be lifted, and appropriately reduce the width of the sealing surface according to the requirements of the drawing to complete a useful seal. . Fourth, the valve core and valve seat are deformed and leak. The primary reason for the leakage of the valve core and valve seat is that the forging or forging defects in the production process of the regulating valve can lead to increased corrosion. The passage of the corrosive medium and the scouring of the fluid medium can also cause leakage of the regulating valve. Corrosion mainly exists in the form of corrosion or cavitation. When the corrosive medium passes through the regulating valve, it will corrode and impact the valve core and valve seat materials to make the valve core and valve seat oval or other shapes. As a result, the valve core and valve seat are not matched, there are gaps, and leakage occurs due to inadequate closing. The key to the solution is to control the selection and quality of the valve core, valve seat and other raw materials. Select corrosion-resistant materials, and resolutely remove defective products such as pitting and trachoma. If the deformation of the valve core and valve seat is not too severe, fine sandpaper can be used to grind to eliminate traces, improve the sealing brightness, and improve the sealing function. If the damage is severe, the valve should be replaced from the beginning. Keywords: mechanical seals, mechanical seals, mechanical shaft seals