Hunter Industries WFS-R Owners Manual Page: 15

Winterization Process For Hunter WFS
Flow sensors can potentially be damaged by winterization blow-out
techniques, and should be removed prior to injecting compressed
air into the pipes.
WFS sensors are installed in FCT tee fittings. The flow sensor itself
includes an impeller, which rotates in the flow on a metal spindle.
When compressed air is used to blow standing water out of pipes,
the impeller spins much more rapidly than usual, and can be
The FCT fittings are supplied with a blank plug (P/N 536100)
installed inside the adaptor. This is removed when the actual flow
sensor is installed.
Save this blank plug and use it to temporarily replace the flow
sensor during winterization blow out, to prevent damage to the
sensor from high velocity air.
1. Shut off the water supply
2. Unscrew the threaded cap
3. Remove the flow sensor assembly
4. Insert the blank plug, and replace the threaded cap
5. Proceed with the compressed air blow out
6. Reinstall the flow sensor and tighten threaded cap
The flow sensor will then be ready for the next irrigation season.
Replacement plugs are available from Hunter Industries as P/N