Brochure

Shut-off valve
Thermostatic valve
Manual valve
Electric pump
Room thermostat
Differential by-pass
Air vent valve
Differential by-pass
valve
RT
RT
RT
RT
CALEFFICALEFFI
CALEFFI
System with 6442 series two-way zone valves, differential by-pass valve
The system works with variable flow rate and it is necessary to keep the pressure differential generated by the zone valves closing under
control. This increase, which can reach unacceptable limits for the system to work properly, translates into an increase in the flow rate to the
circuits still open, with problems for the pumps and the boiler. It is therefore necessary to keep the pressure differentials under control by means
of differential by-pass valves or variable speed pumps.
Application diagrams
In systems with zone control, action is taken to automatically cut off the circuits serving the heat exchanger terminal emitters, according to the
temperature reached in the room. This circuit closing can however cause changes in pressure and flow rate throughout the system so it is
essential to make sure these changes are kept under control within acceptable limits.
System with code 6443.. 3BY three-way zone valve with by-pass