By Josh Cosford, Contributing Editor
No matter how well engineered or manufactured, no product has infinite reliability, including hydraulic valves. Valves are critical components in hydraulic systems, responsible for controlling the flow, direction, and pressure of the hydraulic fluid circulating to transmit work. When a valve fails, it can cause system downtime, decreased productivity, and even damage to other downstream components if it releases particles into the hydraulic fluid. Understanding the reasons why hydraulic valves fail can help you prevent these issues from occurring.
One of the most common reasons for hydraulic valve failure is contamination. The hydraulic fluid that flows through the system can become contaminated with dirt, debris, and internally-generated metal particles. Suppose contaminated fluid makes its way to the valve. In that case, it may work itself into the small clearances between the spool and body, scoring one or both surfaces, eventually leading to internal leakage. Larger particles may prevent the valve from functioning correctly entirely. Regular maintenance and high-quality filtration can reduce contamination and extend the life of hydraulic valves.
Another reason for hydraulic valve failure is general wear and tear. Hydraulic valves are subjected to a lot of stress and strain from repeated pressure cycles, which causes components such as seals and springs to become worn or fatigued, leading to eventual failure. As well, the electrical coils that activate the valve can burn out over time or even sometimes catastrophically.
When you subject a valve to excessive pressure, that type of overloading could fatigue the valve faster at best or break it entirely at worst. In addition, if the valve is subjected to more pressure than it can handle, it can become stuck or damaged, preventing it from opening or closing properly. Proper system design and pressure control can help prevent overloading and extend the life of hydraulic valves.
Corrosion is another potential cause of hydraulic valve failure, particularly in harsh environments such as saltwater or acidic chemical environments. Corrosion can weaken the valve and cause it to become brittle, leading to failure, and any rust created is a potential source of contamination for the valve and other components. Should you not avoid a corrosive environment, choose materials for the valve suitable to resist, such as stainless steel. In addition, regular cleaning can help prevent corrosion and extend the life of hydraulic valves.
Finally, improper maintenance also contributes to hydraulic valve failure. Lack of regular maintenance, especially with the hydraulic fluid crucial to valve health, is of utmost importance. Failing to follow a regular fluid sample and test program might leave you clueless if the oil needs changing. Even when filtered well, the oil may lose its additives over time, reducing lubricity, corrosion resistance and anti-oxidant capacity.
By understanding these factors, you can take steps to prevent valve failure and ensure your hydraulic system continues to operate efficiently and reliably. Proper maintenance, system design, and pressure control are all key to extending the life of hydraulic valves and preventing downtime and damage.
Filed Under: Components Oil Coolers, Engineering Basics, Mobile Hydraulic Tips, Valves & Manifolds