In fluid control systems, the stable operation and precise control of valves depend not only on the performance of the equipment itself but also on the professional skills employed during operation and maintenance. Field experience and system summaries show that mastering the handling methods for key aspects can effectively reduce failure rates, extend service life, and ensure that process parameters are accurately achieved within safe ranges.
Selection and matching techniques are paramount. When dealing with complex media and variable operating conditions, priority should be given to analyzing the chemical properties of the media, particulate matter content, and extreme temperature and pressure values to determine the corrosion resistance level and structural form of the materials. For example, for slurries containing solid particles, a straight-through structure supplemented with wear-resistant internals is preferable to reduce clogging and erosion; for applications requiring tight shut-off, a combination of hard seals or resilient seats is recommended to improve sealing reliability. Simultaneously, the opening and closing torque of the valve under full differential pressure should be calculated to ensure that the thrust or torque of the selected actuator has an appropriate margin to avoid overload damage.
Installation and commissioning techniques are crucial for achieving initial performance. Before welding, valve bevels should be cleaned and preheated to control interpass temperature and prevent embrittlement of the heat-affected zone. For flange connections, ensure the sealing surface is flat, the gasket is centered, and bolts are tightened evenly in a diagonal sequence to prevent micro-leakage due to uneven stress. During commissioning, it is recommended to first conduct a low-pressure stroke test to observe the smoothness of the opening and closing process and check for any jamming or abnormal noises. Then gradually increase to the rated operating conditions to promptly identify potential problems.
Operating techniques emphasize smoothness and repeatability. When operating manual valves, avoid rapid opening and closing to prevent water hammer or pressure shocks from damaging pipelines and sealing surfaces. For control valves requiring precise positioning, a slow and gradual approach should be used, and the correspondence between opening degree and flow rate should be confirmed based on feedback from field instruments. In automated systems, valve action rates and acceleration/deceleration curves should be appropriately set to shorten response time and reduce mechanical shock.
Maintenance and troubleshooting techniques emphasize prevention first and rapid identification. Regularly check for wear on sealing surfaces, aging of packing, and lubrication of the actuator; repairs can be made at the early stages of leakage. For internal leaks, the leak point can be determined through differential pressure testing or tracer gas methods; for external leaks, the integrity of flanges, threads, and welded joints should be checked. When sluggish or incomplete operation occurs, first rule out abnormalities in the gas or power supply, then inspect limit switches, transmission components, and signal circuits. Experience shows that establishing valve operation logs and maintenance records helps identify patterns of periodic degradation and develop targeted maintenance plans.
In summary, valve operation and maintenance skills cover the entire process from selection and matching to on-site handling, emphasizing understanding of operating conditions, attention to detail, and keen judgment of anomalies. Systematically applying these skills in practice not only improves control accuracy but also significantly enhances the safety and durability of fluid systems.