Shuangda Hydraulic Machinery is one of the professional pilot controlled check valve manufacturers and suppliers in China,Website:://.chinahydraulic-valve.com, welcome to buy cheap and low price pilot controlled check valve made in China from our factory.Usage and characteristic  Z2S Pilot controlled check modular valve is used to close one or two of the oil working ports. It has the advantage of no leakage, long duration and reliable stability. The oil flows freely from A to A1 or from B to B1, but can’t run reversely. In order to keep the cone spool closed reliably, when the directional valve is in the central position, working port of the valve will connect with return port.