A pressure regulation servo-valve comprising a body having a utilization port, a feed port, and a return port, a spool mounted as a sliding fit in the body, the spool co-operating with the body to define a pilot chamber connected to the utilization port. The spool and the body together further define a priming chamber connected to the feed port via a second constriction and connected to the nozzle via a third constriction, and in which there exists a priming pressure acting on the spool in the first direction.

A pressure regulation servo-valve comprising a body having a utilization port, a feed port, and a return port, a spool mounted as a sliding fit in the body, the spool co-operating with the body to define a pilot chamber connected to the utilization port. The spool and the body together further define a priming chamber connected to the feed port via a second constriction and connected to the nozzle via a third constriction, and in which there exists a priming pressure acting on the spool in the first direction.

In a closed loop control method for an electropneumatic field device, an electronic target value input of a command variable corresponding to a target value of a control center is received by the open loop and/or closed loop control electronics, an electronic output for a manipulating variable to pilot the electropneumatic converter is generated by the open loop and/or closed loop control electronics; and, in a predetermined operating condition of the field device, the manipulating variable is determined by a closed loop control algorithm based on the command variable and on another controlled variable different from an actual control member position measurement value.

A balance beam electro-pneumatic converter (100, 400) adapted to couple to a conduit with a fluid is provided. The balance beam electro-pneumatic converter (100, 400) includes a nozzle (184) adapted to fluidly couple to the conduit, and a flapper (130) rotatably coupled to the nozzle (184) via a pivot (140) wherein the flapper (130) is adapted to regulate a pressure of the fluid and balance about the pivot (140).

In a positioner, a driving signal IM is set to IMMIN (the minimum), a valve opening position A after the valve has then settled is stored, the driving signal IM is set to IMMAX (the maximum), a valve opening position B after the valve has then settled is stored, and the valve opening positions up until the opening of the valve arrives at the valve opening position B from the valve opening position A are stored together with the elapsed times as time series position information J1, where, based on this stored time series position information J1, the time for the opening of the valve to traverse between two prescribed valve opening positions that are established in the interval between the valve opening position A and the valve opening position B is calculated as a first response time Tup.

An electropneumatic positioner for a pneumatic actuator to operate a control device of a processing plant can include two modular pneumatic slots and a pneumatic control output. The two modular pneumatic slots can engage with a respective modular pneumatic component. The two pneumatic slots and the pneumatic components can be modularly matched to one another such that their respective pneumatic interfaces merge into one another when a pneumatic slot is engaged. The pneumatic control output can output a pneumatic control pressure signal to the pneumatic actuator. The two modular pneumatic slots and the pneumatic control output can form a pneumatic series connection.

Methods and apparatus are disclosed for automatically detecting the failure configuration of a pneumatic actuator. A control module is operatively coupled to the actuator, and the actuator is operatively coupled to a valve having a flow control member. When a number of pilot valves included in the control module is indicative of a double-acting actuator, the failure configuration of the actuator is determined based on the number of pilot valves. When the number of pilot valves included in the control module is indicative of a single-acting actuator, the failure configuration of the actuator is determined by comparing a first measurement value obtained in response to moving the flow control member in a first direction to a first position and a second measurement value obtained in response to moving the flow control member in a second direction opposite the first direction to a second position.

The measured operation time of a setting/operating device is corrected using a first corrected value table and a second corrected value table and the size of the setting/operating device is defined based on the corrected operation time. The first corrected value table defines, as a first corrected value, the corrected value corresponding to the operation time region defined so as to correspond to the size of the setting/operating device and the sliding resistance region defined by dividing the range taken by the sliding resistance (friction) of the valve stem of a regulating valve and the second corrected value table defines, as a second corrected value, the corrected value corresponding to the operation time region defined so as to correspond to the size of the setting/operating device and the supply air pressure region defined by dividing the range taken by a supply air pressure.

The position controller for a pneumatic field device comprises a current-pressure transducer system having at least two I/P-transducers creating separate pneumatic control signals. Microelectronics creates at least two electrical control signals for the I/P-transducers. A pneumatic signal switching valve has at least two pneumatic inputs for the at least two pneumatic control signals, a pneumatic output for transferring a pneumatic control signal to a working chamber of the pneumatic field device and an electrical switch signal input. The pneumatic signal switch valve comprises a first switch position which blocks a first of the at least two pneumatic control signals and a second switch position which blocks a second of the pneumatic control signals.

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.