By means of VA 409 with flow direction indication the flow direction of the compressed air can be determined quickly and safely. Compared with the former mechanical paddle flow switches VA 409 is able to detect even the smallest changes in the flow direction quickly and without any mechanical movement.

The direction information in form of a potential-free contact (normally closed max. 60 VDC, 0.5 A) is transferred to the
consumption sensors VA 400/VA 420 or to a separate building management system (mbs). Two LEDs show the flow direction.

In connection with 2 consumption sensors VA 400/VA 420 incoming and outflowing compressed air in closed circular pipelines
can be measured precisely.

Special features

• detects smallest changes < 0.1 m/s referred to 20 °C and 1000 mbar
• no mechanical wear parts

easy installation under pressure