9
Freeze Protection
The freeze protection backflow prevention assembly may be subject
to damage if the internal water is allowed to freeze. The unit must
be protected from freezing using a heated enclosure, insulation
using heat tape, or other suitable means. The unit must always be
accessible for testing and maintenance. If the system is shut down
during freezing weather, use the following procedures to drain
internal passages.
Main Valve Draining
1. Close the main shutoff valve.
2. Open the inlet drain.
3. Open the inlet and outlet ball valves 45 degree (half open/half
closed).
4. Open all test cocks then open the outlet drain.
5. Remove the cover and inlet check module until all water inside the
valve drains back through the inlet drain.
6. If the piping downstream of the backflow assembly is blown out
with compressed air, connect the air supply to the outlet drain
and close the outlet ball valve. After clearing the system with air,
partially open the outlet ball valve.
7. Leave all drain valves, test cocks, and ball valves in the half open/
half closed position for the winter.
8. For reduced pressure units only. Loosen the relief valve cover to
drain, then tighten when draining is completed.
9. Reset the ball valve to the close position (handle perpendicular to
the valve) before repressurization..
Ball Valve Shutoff Draining
If the assembly has been installed with ball valve shutoff valves, the
ball valves must also be properly drained to prevent freeze damage.
1. Ensure the main valve draining is finished and all ball valve shutoffs
and test cocks are in a half open/half closed (45 degree) position.
2. Drain the pipeline to allow water between the ball valves and valve
body to drain.
3. Leave the ball valves in the half open/half closed position for the
winter to prevent freeze damage.
4. Fully close the ball valves before the system is repressurized.
NOTICE
OPEN AND CLOSE BALL VALVES SLOWLY TO PREVENT
DAMAGE TO THE SYSTEM CAUSED BY WATER HAMMER.
