FIELD: physics; control.
SUBSTANCE: control loop of a regulating valve works using terminal pressure of a pneumatic amplifier as a regulation parametre. The control loop can continuously operate in pressure control mode or can be switched to that mode from displacement control mode, in response to certain operation conditions: operation in the shut-off range, operation when the throttle element (valve 26) reaches the end of its displacement or as a double regulation parametre when the sensor fails. Operation of the control loop in pressure control mode also allows for diagnosing (testing) components (24, 26) of the control loop even if the system is operating in the shut-off range or if the end of displacement of the valve 26 has been reached. Diagnosis can be carried out using pressure and displacement sensors. A processor is programmed to receive data from sensors and generate error signals in accordance with a logical subprogram, involving calculation of flow of control fluid media through outlet windows of the pneumatic amplifier and comparing other operating parametres to detect leakages and clogging in components of the control loop.
EFFECT: invention increases efficiency of a regulating valve, with natural gas serving as the control medium.
67 cl, 13 dwg
