VK309 Flow Switch

The SIKA VK309 flow switches are used for monitoring volume flows. Depending on conditions, the SIKA VK309 flow switch is available for various nominal widths and set-point ranges. The SIKA VK309 flow switch contains a paddle system to whose end a permanent magnet is attached. Above this magnet is a reed contact, located outside the flow of fluid. A second magnet creates the force necessary to reset the switch back to the no-flow position.

When the flow being monitored pushes against the paddle system, the paddle swings away. This changes the position of the magnet in relation to the reed contact and thus activates the connection.

As soon as the flow is interrupted, the paddle moves back to its starting position, thus activating the reed contact once again. The force necessary to push the magnet back is provided by the two magnets repelling each other. Using magnetic force instead of the usual leaf spring means that the switch is considerably more stable in the long term and much less sensitive to pressure peaks.