Water piping — general information, Gold cgs gas-fired water boiler — boiler manual, General piping information – Weil-McLain GOLD CGS 550-110-260/0508 User Manual
Page 14: Pressure/temperature gauge, Relief valve, Circulator, System water piping
 
Part number 550-110-260/0508
14
GOLD CGs Gas-Fired Water Boiler — Boiler Manual
Water piping — general information
3a
Table 3
Water pipe size (based on 20°F rise)
General piping information
If installation is to comply with ASME or Canadian requirements, an ad-
ditional 
high temperature limit
is needed. Install control in supply piping
between boiler and isolation valve. Set second control to minimum 20°F 
above setpoint of fi rst control. Maximum allowable setpoint is 240°F. See 
Section 
9b
, page 32 for wiring.
A
low water cutoff device
is required when boiler is installed above ra-
diation level or by certain state or local codes or insurance companies. Use 
low water cutoff designed for water installations. Electrode probe-type is 
recommended. Purchase and install in tee in supply piping above boiler.
Use
backfl ow check valve
in cold water supply as required by local
codes.
Pressure/temperature gauge
Install pressure/temperature gauge in tee on supply piping (as shown in 
drawing on page 3).
Relief valve
Install relief valve vertically in ¾” tapping on side of boiler. See
Figure 4 or 5
,
page 15, and the tag attached to the relief valve for manufacturer’s instructions.
Circulator
The circulator is shipped loose (wiring pre-attached to 
boiler) to allow you to locate it either in the return or 
supply piping, as desired. See page 3 for a typical instal-
lation. Pipe the expansion tank to the suction side of the 
circulator whenever possible. Install an air separator in 
the supply piping. Connect the expansion tank to the air 
separator only if the separator is on the suction side of 
the circulator. Always install the system fi ll connection 
at the same point as the expansion tank connection to 
the system. 
Figures 4
and
5
, page 15, show typical near-
boiler piping connections.
System water piping
See
Figure 4
(diaphragm-type or bladder-type expan-
sion tank) or
Figure 5
(closed-type expansion tank) on
page 15, and
Table 3
below, for near-boiler and single-
zone systems designed for return water at least 130°F.
See pages 16-17 to complete multiple-zone piping or 
pages 18-23 to complete piping for radiant heating 
systems or converted gravity systems (large-volume 
systems originally designed for circulation by natural 
convection rather than a pump).
Chillers or air handling units
:
Install boiler such that —
• Chilled medium, if used, is piped in parallel with
heating boiler. Use appropriate valves to prevent 
chilled medium from entering boiler. Consult 
I=B=R Installation and Piping Guides.
• If boiler is connected to heating coils located in
air handling units where they can be exposed to 
refrigerated air, use fl ow control valves or other au-
tomatic means to prevent gravity circulation during 
cooling cycle. Circulation of cold water through the 
boiler could result in damage to the heat exchanger, 
causing possible severe personal injury, death or 
substantial property damage.
To avoid water damage or scalding due to relief valve
operation:
• Discharge line must be connected to relief valve outlet and
run to a
safe place of disposal
. Terminate the discharge line to eliminate
possibility of severe burns should the valve discharge.
• Discharge line must be as short as possible and be the
same size as
the valve discharge connection
throughout its entire length.
• Discharge line must
pitch downward
from the valve and terminate
at least 6” above the fl oor drain where any discharge will be clearly 
visible.
• The discharge line shall
terminate plain, not threaded
, with a mate-
rial serviceable for temperatures of 375°F or greater.
•
Do not pipe the discharge to any place where freezing could
occur.
•
No shutoff valve
shall be installed between the relief valve and boiler,
or in the discharge line. Do not plug or place any obstruction in the 
discharge line.
•
Failure to comply
with the above guidelines could result in failure of
the relief valve to operate, resulting in possibility of severe personal 
injury, death or substantial property damage.
•
Test the operation of the valve
after fi lling and pressurizing system
by lifting the lever. Make sure the valve discharges freely. If the valve 
fails to operate correctly, replace it with a new relief valve.
Boiler
model
number
To
system
From
system
CGs-3/4/5
1"
1"
CGs-6
1 ¼"
1 ¼"
Note: The boiler supply and return connections, the return/
drain tee and the supply/gauge tee supplied with the 
boiler are 1¼” NPT. One of the circulator flanges sup-
plied with the boiler is 1¼”. The other circulator flange 
is the size of the recommended system piping shown 
above.