SAMSON 3730-1 7107251

Overview

SAMSON TROVIS 3730-1, serial reference 7107251, is an electropneumatic valve positioner from the Samson 3730 series. It receives a 4–20 mA analog control signal from the process controller and regulates air pressure to pneumatic linear or rotary actuators to accurately position the control valve. It is widely supplied as exchange spare for chemical, power, water and oil & gas control loop overhaul and positioner replacement.

Features

SAMSON 3730-1 adopts non-contact travel sensing design, eliminating wear from mechanical feedback linkage. It supports automatic initialization and self-calibration to adapt to actuator stroke and friction characteristics. Multiple valve characteristic curves are selectable: linear, equal percentage, reverse equal percentage and dedicated profiles for butterfly and rotary plug valves. The built-in LCD display with single rotary pushbutton allows local parameter configuration and stroke reading; the screen orientation can be rotated 180° for flexible mounting directions.

SAMSON 3730-1 is a two-wire low-power unit. It supports single-acting actuators directly, and works with the 3710 reversing amplifier for double-acting actuators. It does not include HART communication (HART function belongs to 3730-3 variant). Configuration and offline diagnostics can be performed via TROVIS-VIEW software through the SSP service interface. It has adjustable air output capacity and optional limit switch accessories for remote valve status feedback. The die-cast aluminium housing offers robust EMC and vibration resistance for field installation.

Specs

SAMSON 3730-1Platform: Samson TROVIS 3730 series Type: electropneumatic positioner Serial number: 7107251 Setpoint signal: 4–20 mA DC, two-wire Supply air: 1.4–7 bar Stroke range: 3.75–200 mm linear; 24–100° rotary Actuator compatibility: single-acting, double-acting (with 3710 reversing amplifier) Characteristic: linear, equal percentage, reverse equal percentage, butterfly valve curve Local interface: LCD + rotary pushbutton Communication: no HART Mounting: IEC 60534-6, VDI/VDE 3845 / 3847, NAMUR standard Enclosure: die-cast aluminium This is not a control valve, actuator or solenoid valve; it is the core positioning controller for pneumatic control valves. SAMSON 3730-1 is widely supplied as service replacement spare for modulating control valve positioning loop failure.

Principle

SAMSON 3730-1 compares the 4–20 mA setpoint signal with the actual valve stroke measured by the non-contact sensor. If deviation exists, the internal I/P module adjusts the output air pressure to fill or exhaust the actuator chamber. When the measured stroke matches the target value, the air supply stabilizes. The internal pressure regulator compensates fluctuations in instrument air supply, maintaining stable positioning accuracy. Hysteresis and sensitivity parameters are tuned to balance response speed and stability.

Applications

SAMSON 3730-1 is deployed for flow, pressure, level and temperature control loops in chemical plants, power stations, water treatment facilities and oil & gas processing sites. It is selected for spare inventory and control valve retrofit projects for existing Samson 3730 pneumatic modulation systems.