Piston needle valve manufacturer in China: The automatic control valve is an essential component for optimising system performance. The S900 series of automatic control valves are Basic valves to provide hydraulically driven solutions to pressure, flow and level control applications. We are an automatic control valve manufacturer & hydraulic control valve supplier since 2004, all of our industrial Automatic Control Valves have passed a series of international quality assurance systems and product safety certifications. Features: Top and seat ring guided stem and diaphragm assembly for long life and reliability. All iron components are fusion epoxy bonded for corrosion resistance. Easy …