Piping Snow Melt Systems/Combination Snow Melt/Space Heating Systems; Manual Bypass Valves; Auto Return Temp Regulation - Weil-McLain Gold GV Manual

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IIIi
Water piping — snow melt system
Figure 15a
Figure 15b Auto return temp regulation; for
Part number 550-141-856/0703
Manual bypass valves; for fixed
temp operation only
outdoor reset or fixed temp
Piping snow melt systems or
combination snow melt/space
heating systems
Combination snow melt/space heating systems will
have widely varying system return temperatures. So
these systems require automatic return water
temperature as shown in Figure 15a (zone-valve
zoning) or Figure 15b (circulator zoning).
Select an automatic temperature control valve or
motor-operated valve which can be adjusted to provide
a return water temperature of at least 60 °F. Any setting
higher than 60 °F will also be acceptable.
Zone-valve zoning — The suggested piping uses a
separate circulator for system circulation to assure good
temperature distribution in the system when the return
water temperature is low.
Circulator zoning — The GV internal circulators must
not be removed. Provide a separate circulator for each
zone.
The return water temperature to the
boiler must be at least 60 °F. Provide
and apply means to regulate the
return temperature. Failure to do so
can result in boiler control
operation problems, causing
possible significant property
damage.
Legend
1 Isolation valves
2 Automatic air vent (with diaphragm-type
expansion tank), or connect to tank fitting
(closed-type expansion tank).
3 Diaphragm- or bladder-type expansion tank,
if used (For closed-type expansion tank, pipe
from top of air separator to tank fitting as in
Figure 10.)
4 Zone valve
5 System or zone circulator
6 Flow/check valve
7 Hose bibb purge valve
8 Boiler pressure/temperature gauge
9 System supply temperature gauge
10 Return temperature automatic mixing valve
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