Abstract:
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.
Abstract:
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.
Abstract:
Methods and apparatus to partial stroke test valves using pressure control are disclosed. An example method includes generating a first pressure set point for a valve positioner coupled to an actuator to actuate a valve. The first pressure set point is associated with a partial stroke test of the valve. The example method also includes controlling an output pressure of the positioner towards the first pressure set point to actuate the valve in a stroke direction. The example method further includes determining whether the valve is stuck based on the output pressure.
Abstract:
A pneumatic volume booster to amplify a control pressure output signal can include a pneumatic control outlet for attachment to a pneumatic working chamber of the pneumatic actuator; a pneumatic aeration inlet configured to receive the pneumatic control pressure signal from the position controller, a pneumatic amplification inlet configured to receive a constant pneumatic air amplification signal, a pneumatic de-aeration connection from the control outlet to a pressure sink configured to aerate the control actuator, a deaerator seat-valve separating and/or opening the pneumatic de-aeration connection, a pneumatic aeration connection between the first aeration inlet and the control outlet; an aerator seat-valve separating and/or opening the pneumatic aeration connection, a pneumatic amplification connection between the amplification inlet and the control outlet; an amplification seat-valve separating and/or opening the pneumatic amplification connection; and a mechanical seat-valve-operator for commonly operating the de-aeration seat-valve, the first aerator seat-valve and the amplification seat-valve.
Abstract:
An electro-pneumatic controller adapted to use a non-inert fluid as a control fluid includes a base portion and a cap portion removeably secured to the base portion. A non-intrinsically-safe process may be disposed within an interior of the cap portion. A plurality of passageways may be disposed through the base portion. The electro-pneumatic controller may also include a flameproof barrier assembly which may include a plurality of flameproof joints each disposed within desired portion of the plurality of passageways. The plurality of flameproof joints cooperate to at least partially define a first zone, the flameproof joints adapted to prevent or to limit the spread of an open fire or explosion that might occur due to the ignition of the non-inert control fluid.
Abstract:
An apparatus includes a plurality of pneumatic linear actuator modules, a dynamic actuator linkage, and a static actuator linkage. Each of the plurality of pneumatic linear actuator modules includes a static portion and a dynamic portion. The dynamic portion is movable in a linear fashion relative to the static portion. The dynamic actuator linkage connects the dynamic portion of each of the plurality of pneumatic linear actuator modules to a moveable portion of a device. The static actuator linkage connects the static portion of each of the plurality of pneumatic linear actuator modules to an immoveable portion of the device. A number of pneumatic linear actuator modules one less than the plurality of pneumatic linear actuator modules are able to provide linear actuation to the device. Each of the plurality of actuator modules is configured to selectively couple and decouple to the dynamic actuator linkage and the static actuator linkage.
Abstract:
A valve positioner that can maintain operation of the control valve despite failures in one or more components. The valve positioner may reduce downtime by allowing in-situ repair to occur on the valve positioner. The valve positioner may incorporate a by-pass component, which can utilize control input signals (e.g., a 4-20 mA signal) to energize one or more components (e.g., a current-to-pressure converter) to cause the control valve to modulate fluid flow without the digital microprocessor and/or related components.
Abstract:
A parameter acquiring device for acquiring parameters for a control valve has a controlling valve operating unit, a valve opening signal acquiring unit and a parameter calculator. The controlling valve operating unit operates a controlling valve in an opening direction and in a closing direction by changing, in a specific sequence, a control signal that controls an opening of a regulator valve. The valve opening signal acquiring unit acquires a signal indicating an actual opening of the regulator valve. The parameter calculator acquires data pairs of control signals and valve opening signals. The parameter calculator calculates a parameter of the control valve based on the data pairs that have been acquired.
Abstract:
A valve positioner system with zero bleed at steady state is disclosed. The system has a pilot valve, the operation of which is controlled by an electronic circuit powered from a signaling and power connection of a positioner device. A plurality of pneumatic valves are activated and deactivated by the pilot valve to control a valve actuator. With varying configurations and arrangements of normally open or normally closed pilot valves and pneumatic valves, fail freeze and fail safe operations are contemplated. The activation and deactivation of the pilot valve is controlled by an electronic circuit that monitors a valve position signal.
Abstract:
A digital valve positioner for use with an actuator. The digital valve positioner includes a housing, at least one exhaust port opening formed in the housing, and a vent assembly operatively coupled to the at least one exhaust port opening. The vent assembly includes a body having a bore, a valve seat surrounding the bore, and a check valve disposed within the bore. The check valve is arranged to shift from a closed position seated against the valve seat to an open position disposed away from the valve seat. A plurality of barriers is disposed around and positioned to enclose the check valve. The plurality of barriers is arranged to prevent an external medium from entering the check valve and to provide a tortuous flow path for the exhaust medium reducing sound through the vent assembly.