Williamson-Thermoflo GWC-070 Manual page 17

GWC S 2
erieS gaS
Install water piping
Figure 18
Zone valve zoning — GWC-070, GWC-105 or
GWC-140 (DO NOT apply to GWC-175)
Figure 19 The system must meet the following requirements when applying Figure 18
Boiler Circulator HEAD
model available to the
system
6.4 feet w.c.
GWC-070
@ 6.5 GPM
4.1 feet w.c.
GWC-105
@ 9.7 GPM
5.5 feet w.c.
*
GWC-140
@8.7 GPM
GWC-175 DO NOT apply to GWC-175 — Use primary/secondary piping ONLY, as in Figure 20, page 18.
* This application may be marginal. It could cause temperature distribution problems, because the temperature drop is 30°F,
NOT 20°F. The best method is to use primary/secondary piping for the GWC-140 as in Figure 20, page 18.
Part number 550-142-786/0712
-
fired water boiler
(continued)
Maximum Minimum
circuit number
length of circuits
L
103 feet 2
92 feet 3
112 feet 3
— Boiler Manual
1 Isolation valves
2 Automatic air vent (with
diaphragm-type expan-
sion 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 Fig-
ure 15, page 14.)
Pipe sizes (NPT), minimum
Boiler model
GWC-070
GWC-105
GWC-140
Circuit requirements
One-pipe diverter tees systems
plication information on this page is based
on two-pipe baseboard systems.
whether the internal circulator can provide
sufficient flow to a one-pipe diverter tee
system, use the available head value given in
Figure 19, page 17.
Max load Max feet baseboard
of any of any circuit
circuit (@ 600 Btuh/foot)
40 MBH 67 feet
33 MBH 55 feet
53 MBH 88 feet
Legend
4 Zone valve
7 Hose bibb purge valve
8 Boiler pressure/tempera-
ture gauge
10 Differential pressure by-
pass valve
16 Cold water fill line — see
Figure 15, page 14 for
typical components
Mains Circuits
1" ¾"
1¼" ¾"
See Figure 19
— The ap-
To check
Summary
6.5 GPM total
(max 4GPM any cricuit)
20°F temperature drop
9.7 GPM total
(max 3.3 GPM any circuit)
20°F temperature drop
8.7 GPM
(max 3.5 GPM any circuit)
30°F temperature drop
17