Flow switches can make or break an electrical circuit when flow starts or when flow stops, and can be used to:
- Actuate a signal when flow stops
- Start a motor with flow
- Shut off an alarm when flow is adequate
- Stop a motor with no flow.
McDonnell & Miller flow switches are equipped with either one or two SPDT switches. Liquid flow switches are for use on pipe sizes 1/2″ to 36″ NPT and air-flow switches are for installation in ducts 6″ or larger.