Dwyer Series TDFS2 Thermal Dispersion Flow Switch

Wiratama Mitra Abadi 01 02.18 flow measurement,

Dwyer Series TDFS2 Thermal Dispersion Flow Switch is a thermal flow switch that indicates whether the flow rate is above or below a user set flow rate. The unit incorporates two LED status indicators providing visual switch indication. The set flow rate (setpoint) is field adjustable and the unit has both NO and NC NPN outputs. See Figure 1 on catalog page for output and LED actions on change of flow.

Thermal flow switches are sensors with an electrical contact output at a specific flow rate. Dwyer models provide a complete system for leak detection and feature a selectable NO or NC operation. Applications include chillers, hot water heaters, and liquid transfer systems.

Dwyer Series TDFS2 Features

Better reliability and life expectancy than mechanical flow switches with no paddles or vanes to wear or break, no jams in the paddle movement, and no seals on movement assembly to wear or leak
Not affected by empty pipe as it avoids overheating by actively heating above the process temperature and then cooling down to process temperature
Set point is easily field set by tapping the included magnet on the set point target three times at the desired flow rate
LED status indicators provide visual switch indication of flow rate in comparison to the set point
Low pressure drop; only needs to be inserted 10% into the flow (e.g. 1/8" for 3/4" schedule 40 pipe)

Application

Boiler flow proving
Hot water heaters
Chillers
Liquid transfer systems

Specification

Service	Compatible water-based fluids.
Wetted Materials	316SS.
Set Point Range	0.5 to 10 ft/s (0.15 to 3.0 m/s).
Repeatability	0.07 ft/s +3% of set point.
Typical Deadband	0.1 ft/s +15% of set point.
Temperature Limits	Ambient: 5 to 140°F (-15 to 60°C); Process: 5 to 140°F (-15 to 60°C); Storage: -40 to 185°F (-40 to 85°C).
Pressure Limits	300 psig (20.67 bar).
Response Time	Approx. 8 s.
Power Requirement	9 to 24 VDC.