Hydraulic and pneumatic systems are important power transmission structures in industrial automation machinery. The sealing ball inside the valve body needs to bear frequent impact, fluid erosion and pressure fluctuation. Silicon nitride balls gradually replace stainless steel balls and become the mainstream sealing component of high-precision hydraulic and pneumatic valves.
High roundness and surface smoothness are the basic advantages of silicon nitride sealing balls. After ultra-precision lapping, the sphericity error is controlled within micrometer level, which can perfectly fit with hard alloy valve seat. Under liquid or gas pressure, zero-gap sealing is realized to prevent medium leakage, solving the leakage problem of ordinary metal balls with poor fitting accuracy.
Impact resistance is essential for valve balls. The opening and closing of hydraulic valves produce instantaneous pressure impact. Silicon nitride balls have excellent fracture toughness, which can withstand thousands of cyclic impacts without cracks or permanent deformation. Metal balls are prone to plastic deformation and surface pits after repeated impact, resulting in poor sealing performance.
High and low temperature adaptability expands the application range of the valve. Silicon nitride balls can work stably from minus 60℃ to 1200℃. In low-temperature hydraulic systems for cold storage equipment, it will not become brittle; in high-temperature steam pneumatic valves, it will not soften and deform. This temperature resistance cannot be matched by ordinary metal sealing balls.
Anti-fouling and erosion resistance prolong valve service life. Impurities and particles in hydraulic oil will continuously erode the sealing surface. The ultra-hard and smooth surface of silicon nitride balls is not easy to adhere dirt, and particle erosion will not leave obvious wear marks. It keeps stable sealing performance for a long time and reduces valve maintenance frequency.
At present, high-end hydraulic solenoid valves, high-pressure pneumatic reversing valves and explosion-proof industrial valves all adopt silicon nitride balls. With the upgrading of industrial automation, the market demand for silicon nitride valve balls will continue to grow.
