When using a pneumatic wrench, insufficient air dryness can allow moisture to enter the equipment along with the compressed air. This moisture can interact physically or chemically with internal components, gradually causing various malfunctions and impacting the equipment's normal operation and service life. First, moisture can cause corrosion on metal components in the air system, such as valves, cylinder walls, and drive shafts. Compressed air often contains trace impurities, which mix with moisture and form a moist layer on the metal surface, accelerating oxidation and corrosion. As rust progresses, problems such as spotting and flaking appear on the metal surfaces. Rust products occupy previously precise clearances, causing valve opening and closing problems and increasing friction between the cylinder wall and piston, leading to air blockage or leaks. Once the air seal performance deteriorates, the compressed air pressure and flow rate will be lost during transmission, resulting in unstable power output from the pneumatic wrench, potentially causing torque drops and speed fluctuations, making it impossible to meet normal operating requirements.
Second, moisture can severely damage internal seals. Pneumatic wrenches typically feature rubber O-rings, gaskets, and other components at their air connections and piston ends. These seals rely on their inherent elastic deformation to achieve a seal. However, moisture can penetrate the rubber, causing it to age, swell, or harden. If a seal expands, it can become lodged in gaps between components, affecting the proper function of the moving parts. If it hardens, it loses its elasticity, preventing a tight seal and directly causing air leaks. More seriously, aged seals are prone to cracking and falling apart. These fragments can enter the transmission mechanism with compressed air, becoming impurities and exacerbating wear on other components, creating a vicious cycle of seal failure, impurity contamination, and component wear.
Furthermore, water intrusion can also cause the lubrication system of internal moving parts to fail. Moving parts like the hammer mechanism, bearings, and drive shafts of a pneumatic wrench rely on a lubricant film to reduce friction and wear. When moisture enters, it mixes with the lubricant, diluting the oil concentration and disrupting the integrity and stability of the film. Without effective oil film protection, metal parts will come into direct contact and friction, resulting not only in severe wear but also in surface scratches, strains, and even metal adhesion caused by frictional heat. For example, the impact block and anvil in the hammer mechanism rely on an oil film to cushion impact and reduce wear. Once this film is disrupted by moisture, the impact contact between them becomes direct and intense, potentially causing surface deformation in the short term, reducing the efficiency of impact torque transmission and causing noticeable jerking during operation. Over time, it can also cause the hammer mechanism to completely seize and stop functioning properly.
Moisture can also affect the accuracy and reliability of control components. Control components such as pneumatic wrenches, such as pressure regulating valves and flow control valves, rely on extremely tight clearances between the valve core and the valve sleeve, relying on precise alignment to adjust compressed air parameters. If moisture enters these components, it can condense into water droplets on the valve core surface or mix with impurities in the air to form dirt, which can clog the gap between the valve core and the valve sleeve and cause the valve core to stick. In this situation, the pressure regulating valve may fail to accurately regulate the air pressure, leading to air pressure runaway. This can result in either excessive pressure, resulting in excessive torque and damage to the workpiece being tightened, or too low pressure, preventing the tightening operation. The flow control valve may malfunction, causing the wrench's speed to fluctuate, further impacting precision. In low temperatures, moisture can also freeze inside the control components, directly freezing the valve core and causing them to fail completely. The pneumatic wrench may not start or even shut down suddenly, posing a safety hazard.
Finally, long-term moisture intrusion accelerates the aging of internal components and shortens the overall lifespan of the equipment. Even if no obvious failure occurs in the short term, moisture's slow corrosion of metal, progressive degradation of seals, and gradual damage to the lubrication system will gradually weaken component performance, reducing the pneumatic wrench's overall reliability and increasing the frequency of failures. For example, bearings that once provided years of normal service may need replacement in just a few months due to moisture. A previously well-sealed air path may experience frequent leaks due to aging seals, necessitating repeated repairs, increasing maintenance costs and delaying normal operations.
