| 主权项 |
1. A fluid flow control device, comprising:
a regulator including an inlet, an outlet, a control element, and a diaphragm assembly having a diaphragm operably coupled to the control element for moving the control element in response to pressure changes across the diaphragm to control the flow of fluid from the inlet to the outlet; a pilot device coupled to the fluid regulator for loading a top surface of the diaphragm, the pilot device including an inlet port adapted to receive a supply of loading gas and having an inlet valve, an exhaust port having an exhaust valve, an outlet port in fluid communication with the top surface of the diaphragm of the regulator, a loading pressure sensor disposed between the inlet valve and the outlet valve and in fluid communication with the outlet port and the top surface of the diaphragm, and an on-board controller communicatively coupled to the inlet valve, the outlet valve, and the loading pressure sensor, the inlet valve operable between an open position to open the inlet port for delivering the supply of loading gas to the outlet port and the top surface of the diaphragm and a closed position to close the inlet port, and the exhaust valve operable between an open position to open the exhaust port and exhaust gas away from the top surface of the diaphragm and a closed position to close the exhaust port; a feedback pressure sensor connected between the outlet of the regulator and the on-board controller of the pilot device, the feedback pressure sensor adapted to periodically sense a pressure at the outlet of the regulator and send a feedback control signal to the pilot controller, the feedback control signal indicative of the magnitude of the detected pressure; the on-board controller including a memory, a processor, and logic stored on the memory, wherein the logic stored on the memory of the controller is executable by the processor for: receiving the feedback control signals from the feedback pressure sensor, comparing each feedback control signal to a set-point control value to determine if the pressure at the outlet of the regulator is greater than a set-point pressure, opening the exhaust valve of the pilot device when a feedback control signal is determined to be greater than the set-point control value so that loading gas in the pilot device can exhaust away from the top surface of the diaphragm of the regulator, receiving a loading control signal from the loading pressure sensor of the pilot device after opening the exhaust valve, the loading control signal indicative of a pressure on the top surface of the diaphragm, comparing the loading control signal to a predetermined minimum threshold value that is less than the set-point control value, closing the exhaust valve when the loading control signal is equal to or less than the predetermined minimum threshold value. |
