Time of publication:

2023-11-06

1. The sealing surface that is not normally open or closed is easy to contact with foreign objects when allowed. Often close or open the valve chamber, leaving a small seam, repeat several times, and flush out the foreign objects on the sealing surface. 2. Equipment and pipe corrosion, welding ballast, bolts and other items stuck on the sealing surface of the valve should be set up sewage, filtration and other protection devices, regular inspection of the protection device and valve bottom plug, remove foreign matter. 3. The medium itself has hard particles embedded in the sealing surface. Generally, gate valves should not be selected. Ball valves, plug valves and soft sealing surfaces should be selected. 4. The sealing surface is uneven or the angle is not straight, not round, can not form a closed line sealing surface processing and grinding method should be correct, before assembly should be colored inspection, printing shadow circle and continuous 5. Improper selection of sealing surface material or valve selection without working conditions, corrosion, erosion wear and other phenomena, strictly in accordance with the working conditions to select the valve or replace the sealing surface. For batch products, the corrosion resistance, wear resistance, wear resistance and other properties of the sealing surface should be tested 6. Sealing surface surfacing and heat treatment are not operated as specified. They wear due to low hardness, corrosion due to the burning of alloying elements, and cracking due to excessive internal stress. Surfacing and heat treatment shall comply with regulations and specifications, and strict quality inspection system shall be adopted 7. The sealing surface hardening, ammonia penetration, boronizing, chromium plating and other processes of sealing surface peeling or loss of original performance due to excessive grinding shall be carried out in strict accordance with the rules and specifications of this technical requirement. When repairing, the cutting amount of the penetration layer of the sealing surface should not exceed 1/3. 8. If the shut-off valve is used as a throttle valve and a pressure reducing valve, and the sealing surface is corroded to cut off the valve, it is not allowed to be used as a throttle valve and a pressure reducing valve, and the closing parts should be in a fully open or fully closed position. If the medium flow and pressure need to be adjusted, throttle valve and pressure reducing valve should be set respectively 9. Close the parts to the fully closed position, continue to apply too much closure, the sealing surface is crushed, the squeeze deformation closing force should be moderate, after the valve is closed, immediately stop closing the valve, correct the "valve closed more strictly, the better" error method of operation.