E+H Flowphant T DTT31 Compact Thermal Flow Switch

Reliable Process Flow Monitoring & Protection

Maintaining consistent liquid flow and protecting machinery against dry running are critical requirements for modern industrial process operations. The Endress+Hauser Flowphant T DTT31 Thermal Flow Switch provides a compact, intelligent solution for continuous flow monitoring and process display in liquid piping systems. Utilizing the calorimetric measurement principle, the DTT31 measures forced thermal convection caused by flowing media, enabling precise detection of relative mass flow rates without requiring internal moving parts that could wear or jam over time.

Flexible Process Monitoring with Dual Switch & Analog Outputs

Designed for industrial process monitoring, the Flowphant T DTT31 offers versatile switching and signal output configurations. Operators can select between single or dual PNP switch outputs, or a combined PNP switch output with an active 4 to 20 mA analog output.

The device can be configured to monitor relative flow velocity (0 to 100%) or process medium temperature (-20 °C to +85 °C / -4 °F to +185 °F). The optional 4 to 20 mA analog output provides a continuous signal proportional to the configured measuring range, enabling seamless integration into remote PLC or SCADA supervisory systems.

Wear-Free Sensor Design with Minimal Head Loss

Unlike traditional mechanical paddle switches or inline flow switches that cause fluid restriction and pressure drops, the DTT31 features an insertion-style sensor probe constructed from corrosion-resistant 316L stainless steel. With no moving mechanical components exposed to the liquid path, the device introduces virtually zero pressure loss while offering superior resistance to mechanical wear and fluid vibration.

The sensor operates reliably in operating pressures up to 100 bar (1,740 psi), making it suitable for high-pressure cooling circuits, turbine lubrication systems, and heavy-duty hydraulic lines.

Operator-Friendly Design with Rotatable Display

The DTT31 features a digital LED display and a 3-key programming interface on-site for fast parameter setup and live diagnostic readings. The upper housing section can be rotated mechanically up to 310°, while the digital display can be inverted electronically by 180°, allowing easy parameter reading regardless of physical mounting orientation.

Continuous internal diagnostics monitor device health and signal output, conforming to DESINA standards and NAMUR NE43 fault signals to ensure plant operators are immediately notified of process irregularities or power interruptions.

 Applications

• Cooling Water Circuits: Flow monitoring and pump protection for compressors, turbines, heat exchangers, and industrial furnaces.

• Pump Protection: Dry-run protection for industrial centrifugal pumps and positive displacement pumps.

• Lubrication System Monitoring: Flow status verification in automated oil lubrication systems and gearboxes.

• Pipe Line Leak Detection: Monitoring fluid movement in industrial water circulation and wastewater lines.

• Filter Monitoring: Flow velocity verification across liquid filtration skids and beverage processing systems.

Technical Specifications

• Manufacturer / Brand: Endress+Hauser (E+H)

• Measurement Principle: Calorimetric / Thermal dispersion measurement.

• Measured Variables: Relative mass flow rate of liquids (0 to 100%), process temperature (-20 to +85 °C).

• Measuring Velocity Range: 0.03 to 3.0 m/s (0.1 to 9.84 ft/s) for liquids.

• Process Media: Water, water-based solutions, low-viscosity oils (viscosity: 0.184 to 20 mPa·s).

• Sensor Probe Material: Stainless steel 316L (1.4435 / 1.4404).

• Insertion Probe Lengths: 30 mm, 100 mm (1.18 in, 3.94 in).

• Max. Process Pressure: Up to 100 bar (1,740 psi).

• Medium Temperature Range: -20 °C to +85 °C (-4 °F to +185 °F).

• Supply Voltage: 18 to 30 VDC (with reverse polarity protection).

• Switch Outputs: 1x PNP switch output, 2x PNP switch outputs, or 1x PNP switch output + 1x active 4-20 mA output.

• Display & Housing: Digital LED display, 310° rotatable top housing, IP65 / IP66 / IP67 ingress protection.

• Process Connections: Threaded connections (G ½”, NPT ½”) or compression fittings.

FAQ

Q1: Is the Endress+Hauser Flowphant T DTT31 supplied as an authentic original unit? A: Yes. We supply 100% genuine, brand-new Endress+Hauser instruments complete with original factory serial numbers, calibration reports, and official documentation.

Q2: Does the DTT31 measure absolute flow rate or relative flow velocity? A: The DTT31 measures relative mass flow rates displayed as a percentage (0 to 100%) based on a configured flow monitoring range. It is primarily used as a flow switch and monitor rather than a full fiscal volumetric flowmeter.

Q3: Can the DTT31 monitor both flow and temperature simultaneously? A: Yes. Depending on the model configuration, the DTT31 can be equipped with dual switch outputs or a switch output plus an analog 4 to 20 mA output, allowing one output to monitor flow and the second output to monitor medium temperature.

Q4: How can I request distributor quotes and confirm lead times? A: Simply submit your required E+H model ordering code, process connection type, probe length, and output requirements through our inquiry form. Our sales team will provide a prompt, competitive quotation and export delivery timeline.

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