Radiator System Piping - Weil-McLain Gold GV Manual

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Water piping — radiator system
Figure 12a
Figure 12b Radiator system — circulator
32
GOLD GV W GOLD GV W
GOLD GV Water Boiler — Series 4 GOLD GV W GOLD GV W
Radiator system — zone-valve
zoning
zoning
ater Boiler — Series 4 ater Boiler — Series 4
ater Boiler — Series 4 ater Boiler — Series 4

Radiator system piping

Apply Figure 12a (zone-valve zoning) or 12b (circulator
zoning) to systems using standing cast iron radiators.
This applies to gravity water systems and converted
steam systems using columnar, tubular or recessed cast
iron radiators.
The suggested piping for zone-valve zoning radiator
systems differs from baseboard systems because of the
high water content of cast iron radiators. The GV
internal circulators automatically regulate supply and
internal bypass flow based on the temperature of the
water returning to the boiler. At the start of many
heating cycles in a radiator system, the water in the
radiators is cool. So the boiler would slow down system
flow rate while sending out relatively hot water. This
could cause heat distribution problems. Install a
separate system circulator as shown in Figure 12a when
zoning with zone valves. The separate circulator assures
a relatively constant temperature drop through the
system.
The boiler internal circulators must be left in the boiler.
They cannot be removed for use a zoning circulator.
Provide a circulator for each zone when circulator
zoning, and pipe the system as in Figure 12b.
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
Part number 550-141-856/0703