Provided are a control method, a control system and an electric valve. The control method includes steps described below. An actually measured setting parameter curve is acquired. A required setting parameter curve is acquired. Both the actually measured setting parameter curve and the required setting parameter curve represent a corresponding relationship between a position of the electric valve and a setting parameter. The actually measured setting parameter curve and the required setting parameter curve are fitted to acquire a position mapping curve. A setting required position is obtained according to a required setting parameter and the required setting parameter curve, and a setting actual position is acquired according to the setting required position and the position mapping curve. The electric valve is controlled to run toward the setting actual position of the electric valve.

A method for operating a fluid system including the steps: receiving or determining a set value for a stroke of the working valve, determining an actual value for the stroke of the working valve using a sensor signal of a position sensor, determining a deviation value of a working valve in dependence on sensor signals of a supply pressure sensor and a working pressure sensor and a position sensor and a sensor system, and performing a processing of the set value for the stroke of the working valve, the actual value for the stroke of the working valve and the deviation value to a control signal for driving the working valve.

A method for performing quality control on a diagnostic analyzer includes receiving control measurement values from each of a plurality of diagnostic analyzers. A quality control measurement value is received from a target diagnostic analyzer. The quality control measurement value is compared with statistical criteria associated with the plurality of quality control measurement values received from the plurality of diagnostic analyzers. A comparison result is communicated to a user interface associated with the target diagnostic analyzer.

A method for performing quality control on a diagnostic analyzer includes receiving control measurement values from each of a plurality of diagnostic analyzers. A quality control measurement value is received from a target diagnostic analyzer. The quality control measurement value is compared with statistical criteria associated with the plurality of quality control measurement values received from the plurality of diagnostic analyzers. A comparison result is communicated to a user interface associated with the target diagnostic analyzer.

An apparatus for monitoring the usage of at least one maintainable part or component of a transfer valve or coupling comprises: data storage means for storing data representative of at least one attribute of the maintainable part or component of the valve or coupling; monitoring means for monitoring usage of the valve or coupling; and processing means for comparing the monitored usage of the valve or coupling against the at least one attribute of the maintainable part or component of the valve.

Embodiments of a method and a system, which is configured to implement the method, to process data from one or more valve assemblies found e.g., on a process line. These embodiments can generate a listing that identifies how network/system bandwidth is allocated for the collection of data from the valve assemblies. The embodiments can also process the data to re-arrange the valve assemblies in the listing to better allocate the network/system bandwidth to certain ones of the valve assemblies that require more data to properly assess the operation of the valve assembly. In this way, further diagnostics using the data can identify any changes in operation of the valve assemblies that might be detrimental to the valve assembly and/or the process line in general.

A method for performing quality control on a diagnostic analyzer includes receiving control measurement values from each of a plurality of diagnostic analyzers. A quality control measurement value is received from a target diagnostic analyzer. The quality control measurement value is compared with statistical criteria associated with the plurality of quality control measurement values received from the plurality of diagnostic analyzers. A comparison result is communicated to a user interface associated with the target diagnostic analyzer.

System for diagnosing pneumatic control valve online include a sensor set having sensors, attached to a pneumatic control valve, for measuring the state of the pneumatic control valve, a smart data analyzer for processing sensor signal acquired in real time from the sensor set and generating pneumatic control valve state information for online automatic diagnosis of the pneumatic control valve, a data server for transmitting, to an online analysis server, the pneumatic control valve state information received in real time from the smart data analyzer and storing the pneumatic control valve state information for predetermined time period, the online diagnostic server for, by comparing the pneumatic control valve state information with pre-stored normal state data of the pneumatic control valve, determining whether the pneumatic control valve is in abnormal state and generating diagnostic information, and a client computer for displaying the diagnostic information received from the online diagnostic server.

Method for diagnosing a pneumatic control valve by using a positioner model includes: establishing relational expression for outputting valve stem displacement according to control pressure, the relational expression including parameters for the characteristics of a positioner, an actuator, and a valve, determining initial parameter value by adjusting the values of the parameters until the difference between a measured value for a normal operation of the pneumatic control valve and output value obtained by the relational expression is smaller than predetermined error limit, determining diagnostic parameter value by adjusting the values of the parameters until the difference between a measured value for a diagnostic operation of the pneumatic control valve and an output value obtained by the relational expression is smaller than a predetermined error limit, and comparing the initial parameter value and the diagnostic parameter value so as to determine whether the pneumatic control valve has abnormality.

An actuator of a process control device continuously monitors actuator force and records high force values at each position point by continuously executing a routine in a processor of the actuator. The routine includes receiving from a position sensor a current position value indicating a position of a valve element in the valve, and from a force sensor a current force value indicating a force applied by the actuator. The routine also includes retrieving, from a memory device coupled to the processor, a previous force value measured at the current position, and comparing the current force values for the current position with the previous force value for the current position. If the current force value for the current position exceeds the previous force value for the current position, the routine replaces the previous force value for the current position with the current force value for the current position in memory.