3730-3

1. General Introduction

Samson 3730-3 valve positioner is Hart communication type suitable for single-acting and double-acting application. It is mounted on pneumatic control valves and used to assign the valve position (controlled variable x) to the control signal (set point w). The positioner compares the electric control signal of a control system to the travel or opening angle of the control valve and issues a signal pressure for the pneumatic actuator.

The positioner mainly consists of a non-contact travel sensor system , pneumatics and the electronics with the microcontroller. The valve position is transmitted either as an angle of rotation or a travel to the pick-up lever, from there to the travel sensor and forwarded to the microcontroller . The PID algorithm in the microcontroller compares the valve position measured by the travel sensor to the 4 to 20mA DC control signal issued by the control system after it has been converted by the A/D converter. In case of a set point deviation, the activation of the i/p module is changed so that actuator of the control valve is pressurized or vented accordingly over the downstream booster . As a result, the closure member of the valve (e.g. plug) is moved to the position determined by the set point. The positioner is operated by a rotary pushbutton for menu navigation on the plain-text display . The extended EXPERTplus diagnostics are integrated into the positioner. They provide information on the control valve and positioner and generate diagnostic and status messages which allow faults to be pinpointed quickly.

2. Selection table of Samson 3730-3 valve positioner

3. Block diagram of Samson 3730-3 valve positioner

4. Liner & Rotary actuator mounting of Samson 3730-3 valve positioner

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  TU807 Communication Module

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  YT 3300 smart positioner

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  Rosemount 2180

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  SRD991

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  DVC6200

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  Topworx DXP