A controller and related system and method for controlling a choke for choking fluid flow are configured to take into account non-linear behaviors of the choke, to allow more accurate and effective control of the choke. To obtain a desired pressure drop across a choke valve, the controller is configured to monitor the position of a choke actuator coupled to the choke valve and the pressure at the inlet of the choke valve. The controller calculates an adaptive proportional gain coefficient, and optionally adaptive integral and derivative coefficients, based on the choke actuator position, to help mitigate the effects of non-linear behaviors of the choke and, where necessary, based on the inlet pressure, the controller calculates an augmentation correction to address any instability in the choke. The controller then commands the choke actuator accordingly to adjust the flow area through the choke valve.

A process control device has an electropneumatic control unit which is used for activating a pneumatic actuating drive. The control unit has a fastening module by means of which it is fastened to a drive housing of the actuating drive. The control unit includes an interface plate which is separate from the fastening module, is mounted on a top side of the fastening module and is fluidically connected, through the fastening module, to the actuating drive. The control unit includes an electrically actuatable control valve device which is fixed to the fastening module by being mounted on the interface plate fixed to the fastening module. In this way, a process control device can be produced in an easily and variably configurable manner.

This invention regards a hydraulic turbine (1) to operate in pressure circuits, where there is a flow of a fluid, to control the flow and pressure downstream the installation point. Even so, said turbine (1) can generate power for itself based on the difference of pressure and flow, as the remaining power can be used in public power networks or isolated. Its application field comprises sanitation companies, beverage industries, paper and cellulose industries, petrochemical companies or any places, where it is needed to control the flow and pressure in supply networks.

An automation device for industrial automation, for closed-loop controlling and/or diagnosing a pneumatic actuator with an actuator member. The automation device has a model, in particular a non-linear model, of the pneumatic actuator, which has at least one model parameter by means of which the model can be adapted to different variants of the pneumatic actuator, and wherein the automation device is configured to carry out closed-loop control and/or diagnosis of the pneumatic actuator using the model.

Methods and apparatus for quantifying pneumatic volume usage via valve controllers are disclosed. An example apparatus includes a valve controller operatively couplable to a pneumatic actuator, the pneumatic actuator being operatively coupled to a control valve. In response to an input signal indicating that a flow control member of the control valve is to be moved in a specified direction, the valve controller commands a current-to-pressure (I/P) converter of the valve controller to pulse a relay valve of the valve controller between a closed position and an open position. The pulsing of the relay valve causes the pneumatic actuator to move the flow control member in the specified direction. The valve controller calculates a pneumatic volume usage associated with the moving of the flow control member in the specified direction. The pneumatic volume usage is based on the pulsing of the relay valve.

A controller and related system and method for controlling a choke for choking fluid flow are configured to take into account non-linear behaviors of the choke, to allow more accurate and effective control of the choke. To obtain a desired pressure drop across a choke valve, the controller is configured to monitor the position of a choke actuator coupled to the choke valve and the pressure at the inlet of the choke valve. The controller calculates an adaptive proportional gain coefficient, and optionally adaptive integral and derivative coefficients, based on the choke actuator position, to help mitigate the effects of non-linear behaviors of the choke and, where necessary, based on the inlet pressure, the controller calculates an augmentation correction to address any instability in the choke. The controller then commands the choke actuator accordingly to adjust the flow area through the choke valve.

A digital positioner for a valve includes a valve controller configured to obtain a set point value for a valve travel of a valve, and generate a pulse-width modulated current signal based on the set point value. The digital positioner also includes a current-to-pressure converter configured to receive the pulse-width modulated current signal from the valve controller, convert the pulse-width modulated current signal to a pulse-width modulated pressure signal, and provide the pulse-width modulated pressure signal to a pneumatic actuator in the valve to adjust a position of the valve.

A controller for a valve assembly that is configured to meet requirements for use in hazardous areas. These configurations may regulate flow of instrument air to a pneumatic actuator to operate a valve. The controller may comprise enclosures, including a first enclosure and a second enclosure, each having a peripheral wall forming an interior space, and circuitry comprising a barrier circuit disposed in the interior space of one of the enclosures that power limits digital signals that exits that enclosure. In one example, the peripheral wall of enclosures are configured to allow instrument air into the interior space of the first enclosure but to prevent instrument air from the interior space of the second enclosure.

An electropneumatic controller has an electropneumatic control unit on which is provided an expansion interface, on which an expansion module arrangement is fitted. In the expansion module arrangement there extends at least one expansion working channel which is connected to a main working output and which is fluidically connected to the control unit at the expansion interface for connection to control valve means. The control unit further contains control electronics for electrically controlling the control valve means. Also proposed is a process control device equipped with a controller of this type.

An arrangement includes a field device with an on/off valve, a pneumatic actuator that moves the on/off valve, when applied with compressed air, into one on/off position and when ventilated into the other on/off position, a magnetic valve that applies compressed air to the actuator during electric actuation and ventilates the actuator during non-actuation and a function monitoring device that detects at least one parameter that refers to the movement of the on/off valve, where the function monitoring device includes a magnetic field sensor detecting changes to a magnetic field, where the magnetic field sensor is arranged in the region of the magnetic valve and generates a signal awakening the function monitoring device to detect the at least one parameter.