The YSI series pilot piston-type stainless steel high-pressure solenoid valve (nominal diameter ranging from DN15 to DN50) is a high-end automated control device specially developed for medium-to-high pressure and large-flow fluid transmission pipelines. As a core executive element in large-bore high-pressure pipeline systems, this series features deep structural optimization targeting common industry pain points under 100bar (10MPa) high static pressure and large-bore working conditions, such as external packing leakage, main seal tearing and destruction caused by large-flow high-velocity scouring, and valve failure to actuate due to insufficient electromagnetic force. The entire series comes standard with high-specification SS304 stainless steel bodies, utilizes a heavy-duty piston guiding structure, and offers two highly reliable interface types: G thread and NPT thread. It is widely used in large high-pressure cleaning pump stations, centralized gas supply networks, hydraulic stations, and various industrial automated large-flow fluid control loops.
This series of valves utilizes a pilot piston-type control mechanism and belongs to the normally closed automatic valve type. Its core advantage lies in the ingenious utilization of the medium's own pressure differential fluid dynamics to drive the large-bore main piston. When the electromagnetic coil is de-energized, the pilot hole remains closed under the action of the return spring force. The medium enters the cavity above the main piston through the fluid channel, forming a balanced or top-high-bottom-low pressure distribution across the upper and lower ends of the piston. Under the combined sealing action of the main spring force and the 100bar medium pressure, the large-bore stainless steel piston is tightly pressed against the main valve seat, achieving absolutely reliable, zero-leakage shut-off.
When the electromagnetic coil is energized, a customized high-power coil instantly generates a strong electromagnetic attraction force that first opens the pilot hole. At this moment, the medium in the cavity above the main piston quickly relieves pressure to the outlet end through the pilot hole. Since the lower side of the piston still bears the high pressure from the inlet end, a huge pressure differential is instantly formed between the upper and lower sides of the main piston. The upward thrust generated by this pressure differential directly overcomes the main spring resistance and the piston's dead weight, rapidly pushing the large-bore main piston upward. The main valve port is instantly fully opened, and the medium restores large-flow, unhindered passage. Once the coil is de-energized, the electromagnetic field disappears, the pilot hole closes at high speed, and pressure rebuilds above the main piston, driving the piston downward rapidly to reset and lock, completing a rapid and rigid cut-off cycle.

Product Image:YSI 2/2-Way Piston Type High Pressure Solenoid Valve