Water Piping - Weil-McLain GOLD CGt Manual

GOLD CGt Gas-Fired Water Boiler — Boiler Manual
4b
Water piping — system
System water piping
Figure 16
See
piping for single-zone systems designed for return water
at least 130°F.
See pages -3 to for multiple-zone piping for systems
with return water tempeature of at least 130°F. See pages
4-5 for low-temperature system piping; i.e., radiant
heating systems or converted gravity systems (large-
volume systems originally designed for circulation by
natural convection rather than a pump).
Table 5 Water pipe size (based on 20°F rise)
Boiler
model number
CGt
Note: The following connections (supplied with the boiler)
are 1¼" NPT – Boiler supply and return tappings;
drain tee; suppy tee; circulator suction-side flange.
The following connections (supplied with the boiler)
are 1" NPT – Circulator discharge-side flange; 3-way
valve and its connected pipe fittings.
• 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 flow 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.
Expansion tank
1. Ensure expansion tank size will handle boiler and
system water volume and temperature. Tank must
be located in boiler return piping as close to boiler
as possible, before inlet side of circulator. See tank
manufacturer's instructions for details.
. Install an
Part Number 550-110-290/0107
and Table 5 for near-boiler piping and
To
system system
1"
Chillers or air handling units
Install boiler such that —
The piping of the CGt boiler re-
quires the use of a bladder-type or
diaphragm-type expansion tank.
Use of a closed-type tank is not
recommended.
Undersized expansion tanks cause
system water to be lost from relief
valve and makeup water to be added
through fill valve. Eventual section
failure can result.
automatic air vent as shown.
From
1"
:
Figure 16
Use Figure 16 only for single-
zone systems designed for re-
turn water at least 130°F. For
systems with low return water
temperature possible, such as
converted gravity systems and
radiant heating systems, refer to
the special piping suggestions of
pages 4-5. Failure to prevent
low return water temperature
to the boiler could cause cor-
rosion of the boiler sections or
burners, resulting in severe per-
sonal injury, death or substantial
property damage.
Piping to single-zone system using dia-
phragm-type or bladder-type expansion
tank. See Table 5 for piping sizes.
1