The FIELDVUE DVC2000 digital valve controller is simple to use, compact, and designed for easy mounting. It converts a 4-20 mA input signal into a pneumatic output signal, which feeds the control valve actuator. Instrument setup is performed with an enclosed push button and liquid crystal display (LCD) interface. The interface supports multiple languages, available in two language pack options. The DVC2000 uses a two-stage positioner design. The pre-amplifier stage provides high static gain for responsiveness to small changes in the input signal. The power amplifier stage delivers the right volume of air to the actuator, combining superior dynamic performance with minimal steady-state air consumption.
| Pressure Range | 5-100 psi (35-700 kPa), (0.35-7 bar) |
|---|---|
| Certifications | PED, CUTR, ATEX |
| Inlet Pressure Rating | 210 psi (1.5 MPa, 15 bar) maximum |
| Operating Temperature | Standard Temperature |
| Connection | SOLENOID |
| Application | Gas& Oil industry |
Principle of Operation The DVC2000 (figures 1 and 2) receives a 4-20 mA set point and position the valve by increasing or decreasing the air output to an actuator. The input signal provides electrical power and the set point simultaneously. The 4-20 mA signal is routed into the terminals through a twisted pair of wires. The unit's mainboard contains a microprocessor that continuously runs a digital control algorithm. This algorithm produces a “drive signal" to the I/P converter. The I/P converter assembly (or pre-amplifier) is connected to supply pressure and converts the electronic “drive signal" into a pneumatic “pressure signal." This pressure signal is the input to the pneumatic relay assembly. The relay (or power amplifier) is also connected to supply pressure and amplifies the small pressure signal from the I/P converter into a larger pressure output signal used by the actuator. The change in relay output pressure to the actuator causes the valve to move. There are two relay options. The low pressure relay operates with actuators that require less than 3.5 bar (50 psi) of supply air. The high pressure relay operates with actuators that require 3.5 to 7.0 bar (50 to 100 psi) of supply air. Valve position is sensed through the linkage-less feedback system. The travel sensor is electrically connected to the printed wiring board to provide a travel feedback signal used in the control algorithm. The valve continues to move until the correct position is attained.
