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V5442N "Corona" 4-way Compact Rotary Mixing Valves — SETTINGS • OPERATION • CHECKOUT
Fig. 7 Primary-secondary loop installation
V5442 must be sized to secondary LOOP flow; acts
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as balancing valve.
SETTINGS
.
The indicator scale on the V5442 ranges from 1 to 9,
where 1 (minimum) corresponds to no flow from boiler to
loop and full return of boiler supply to boiler return. This
scale is approximately proportional to radiation heat out
put, and inversely proportional to boiler return water tem
perature, but is not calibrated and intended for reference
only.
OPERATION
The rotary control plug of the V5442 diverts boiler supply
water to both the loop supply and boiler return. At the
same time, the control plug also diverts loop return water
to the boiler return and back to the loop supply. When the
loop does not use much boiler water, most of it is returned
to the boiler. The loop supply water temperature is the
result of mixing boiler supply and loop return water, and
boiler return water temperature is the result of mixing loop
return water with boiler supply water.
The control plug has a modified equal percentage mixing
characteristic on the mixed loop output to give linear
heat output in the space. The plug uses a linear mixing
characteristic on the mixed boiler return to give linear
temperature control of boiler return water.
The V5442 may be used to control space temperature for
comfort, boiler return water temperature to prevent boiler
shock and condensation, or both simultaneously, depend
ing on the sophistication of the control system.
In low temperature systems such as radiant floor heating,
the V5442 may be used for mixing in an injection configura
tion (See Fig. 8). In these configurations, the V5442 has an
effective Cv of a much larger valve.
95C-10888
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Fig. 8 Injection configuration.
V5442 valve always has flow from and to boiler.
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V5442 must be sized to INJECTION flow; acts
as balancing valve.
CHECKOUT AND TEST
Checkout
1. Turn on loop (and main) circulators. Set the boiler
Aquastat control to its operating setpoint at design
conditions.
2. Rotate valve handle to 9. Verify that all boiler supply
water is being sent to the loop, that is, that the loop sup
ply pipe is the same temperature as the boiler supply,
and the boiler return pipe is the same temperature as the
loop return pipe.
3. Rotate valve handle to 1. Verify that all boiler supply
water is being sent to the boiler return, that is, that the
loop supply pipe is the same temperature as the loop
return pipe, and the boiler return pipe is the same tem
perature as the boiler supply pipe.
4. Rotate the handle to set desired mixed loop tempera
ture. Verify that the boiler return water temperature
meets the boiler manufacturer's or industry recommen
dations. Make
a prominent note of the setting for future reference.
Note: If the boiler is fitted with a reset control such as the
AQ475 Aquatrol Outdoor Temperature Compensator, loop
temperature will vary proportionately with the boiler supply
temperature.
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