TWM Trailing Wire Flow Switch


  • Australian made
  • Low differential switching
  • All direction tilting action
  • S.P.D.T 3 wire switching action
  • Polypropylene, CPE and Santoprene construction
  • Wide range of cable lengths available
  • Stable repeatable switching action
  • No Mercury or lead components
  • Compact size, 75mm diameter
  • Optional cable weight available


The TWM trailing wire flow switch is supplied with a 316 stainless steel process connection and is available in 3/4” or 1” with BSP or NPT threads. The switch housing is machined from solid billet Aluminum. A 500V Single Pole Double Throw (S.P.D.T) microswitch for general control circuit applications is supplied as standard with the TWM.

In addition a low voltage low wetting current model is available for signaling applications. A unique feature of the TWM flow switch is its built in manual override. Using the manual override allows the system to be manually started at any time by simply pressing the button. It also makes testing and commissioning of systems very simple.

The TWM flow switch is available with wire sensors in various lengths from 50mm to 300mm (2” to 12”). The required wire length must be specified when ordering. The flow rate required to actuate the TWM will depend on many variables such as turbulence, liquid viscosity and the surface area of sensor wire exposed to the flow.

More Information

Wire Trimming Calculator

As with our Paddle Flow Switches,  the Trailing Wires for our TWM Series can be cut down in length to suit your pipework if needed. Please refer to our Paddle Trimming Calculator to find the correct wire length for your application. The width of the wires is 2mm.

Please note that if you do cut down the length of your trailing wire, you must either silver solder or tig weld the end of the wire to prevent fraying.