摘要 |
<p>A method and system are provided for controlling a pressurized fluid such as nitrogen gas which may be initially stored at a pressure as high as 20,000 psi. The pressurized nitrogen gas may be utilized in high pressure gas systems such as in gas-assisted injection molding systems or low pressure gas systems such as robotic control and actuators. A valve assembly is utilized in the method and system and includes an electric proportioning device such as a pneumatic servovalve and a pair of pneumatic, fluidly-coupled valves which are piloted by the servovalve to regulate the pressure of the pressurized nitrogen gas. In the method and system, the servovalve operates in a closed loop fashion by utilizing feedback from a feedback device such as a pressure transducer. A controller in the closed loop is responsive to a pressure signal from the pressure transducer and a preset reference signal to provide an error control signal to the servovalve.</p> |