A paddle flow switch with built-in digital timers that override the normally-off state of the switch and let a pump start in spite of an initial lack of flow. Includes an adjustable run-on timer that lets the pump ignore minor flow interruptions while still being fully protected against running dry.
F27 Time Delay
Time Delay Flow Switches
Features
- Dry-run protection for pumps
- Adjustable start-up override
- Adjustable paddle bounce ignore
- All-poly and 316 stainless models available
- 220 / 240 V AC or 24 V AC/DC supply
- Indicator LEDs for all functions
- Weatherproof enclosure
- Suits pipe sizes 25 mm and above
- Poly version: 18 bar (260 psi) pressure rating
- Stainless steel version: 100 bar / 1450 psi
When first powered up the F27 ignores the initial lack of flow and lets a pump under its control run for up to 3 minutes. At the end of the set time the F27 will shut down the pump if there is no flow, or allow it to run on if flow has been established. The F27 has no metal parts in contact with liquids — it operates magnetically through its thermoplastic housings, making it ideally suited to aggressive ground water, seawater, chlorinated water and most acids and alkalis. Made from a blend of ASA and polypropylene specifically tailored for the harshest environments.
More Information
Select Model
Trade customers should contact sales@kelco.co.nz for account pricing.
Ordering — Available Models
| Model Number | Description |
|---|---|
| F27-25B | 1" BSP — polypropylene wetted parts (no metal in contact with the liquid) |
| F27-25B-SS | 1" BSP — 316 stainless-steel process connection (high-pressure model) |
| F27-25N | 1" NPT — polypropylene wetted parts (no metal in contact with the liquid) |
| F27-25N-SS | 1" NPT — 316 stainless-steel process connection (high-pressure model) |
Dimensions
Convertible to Trailing-Wire Sensor
The F27 can be converted to a trailing-wire flow sensor (for fluids containing entrained solids that would foul a paddle) by fitting the separately-sold TW arm kit. Trailing-wire sensors are also more flexible across a wider pipe-size range.
Flow Sensitivity & Paddle Trimming
The flow at which the paddle activates depends on pipe size, fluid viscosity, and trimmed paddle length. Use the online Paddle Calculator to estimate activation flow and determine how much to trim the paddle for your application.
Hazardous Areas
The F27 is not certified for use in hazardous areas and must not be installed in any area classified as hazardous under AS/NZS 60079.10 (Zone 0, 1, 2, 20, 21 or 22).
Serviceability
The F27 is a sealed unit with no metal parts in contact with the liquid; the magnetic suspension system gives a frictionless spring return action and total isolation of the electronics. The electronics are time-tested and surge-protected. Spare parts and replacement paddles available from Kelco Engineering or your distributor.