A spool valve will not perform as intended if you operate it outside of its allowable range of temperatures, pressures and flow velocities. The problem may be that the system as a whole is presenting conditions that are causing the valve to leak.
2. Contamination in flow media
Dirt or unintended particles flowing in the media can cause a valve to leak for several reasons. The particles will cause premature wear as they travel at high speeds through the circuit. It can also prohibit the surfaces of the valve shut-off point to mate correctly, allowing gaps where leakage can occur. If the flow media is capable of escaping the system in the form of a leak, then contaminants can enter the system through that same point. You can control contamination by filtering the flow media and monitoring it for cleanliness.
3. Misalignment between valve stem and actuator stem
If the two stems are misaligned, there can be an uneven force applied to the valve shut-off surfaces which can allow leakage to occur at that point. Any uneven force on the valve stem will also create issues with the packing surrounding the stem. You also need to inspect and test the valve actuator regularly to ensure that it is operating as intended. If it is not capable of mating the shut-off surfaces with the required seating load, then leaks will occur.
The bottom line is that you can minimize both internal and external valve leakage by avoiding the mindset that leaks are inevitable. As discussed, it all starts with sizing and selecting the right valve for the process. Operating the valve within design parameters and adhering to a regular preventive maintenance program can mitigate the majority of industrial valve leakage.
Need more info on managing high-pressure water valve leakage? Learn what causes different types of leaks and how you can prevent them with the right descale valve. Download our free guide, “Managing Leakage in Hydraulic Valve Design.”