To improve the reliability and efficiency of natural gas compression and transmission, the anti-surge control issues need to be addressed comprehensively. High-quality anti-surge control ensures the safe operation of the gas supercharger. Controlled full or partial opening of the anti-surge valve unloads the pumping unit if the supercharger operation mode is reaching a critical level of pressure, compression, or surge. Thus, equipment damaging effects, such as a rapid increase in gas temperature and high vibration, can be avoided. Correct and competent tuning of the anti-surge valve is the keystone of the stable and uninterrupted operation of a gas pumping unit. The article considers the empirical method to select the coefficients for SRD991 positioner, which ensures correct operation of proportional–integral–derivative controller in anti-surge valve manufactured by Mokveld Valves B.V. Unlike the well-known tuning methods, this one accounts for individual features of the control valve: component friction, damages and scuffs on the separator, impulse gas pressure losses due to untight connections, and more. The method allows selecting such proportional, integral, and derivative coefficients for a proportional–integral–derivative controller to ensure the correct shape of transient response whenever the valve is moved.
Keywords: CONTROL VALVE, ANTI-SURGE CONTROL VALVE, POSITIONER, TUNING, PID CONTROLLER, PROPORTIONAL, INTEGRAL, DERIVATIVE COEFFICIENT.