Also known as the hydraulic control one-way valve, when the pilot control port is NOT connected to the high-pressure control fluid, it only allows the hydraulic medium to flow freely in one direction, while being blocked in the opposite direction. When the pilot control port is connected to the high-pressure control fluid, the pilot-controlled check valve allows the reverse flow of the hydraulic medium. The pilot-controlled check valve is used for the position locking control of hydraulic cylinders such as columns, guard rails, and moving frames. Each type of one-way valve is specially designed according to the user's required specifications, installation method, and connection dimensions, such as DN10, DN12, and DN20.