14
Part Number 550-142-785/0812
GWI
Series 2
Gas-Fired Water Boilers –
Boiler Manual
Water piping — refrigeration systems
Prevent chilled water from entering boiler
Install boiler so that chilled medium is piped in parallel with the
heating boiler. Use appropriate valves to prevent chilled medium
from entering boiler. See
Figure 11
for typical installation of
balancing valve and check valve.
Figure 9
Diaphragm- or bladder-type expansion tank:
Piping to single-zone system using
diaphragm-type or bladder-type expansion
tank. See Table 6, page 13, for piping sizes.
Figure 10 Closed-type expansion tank: Piping to single-
zone system using closed-type expansion
tank. See Table 6, page 13, for piping sizes.
Figure 11 Piping refrigeration systems
Install boiler so that chilled medium is piped in par
-
allel with heating boiler. Use appropriate valves to
prevent chilled medium from entering boiler. Consult
AHRI 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.
If system includes radiant heating circuits, provide
piping and controls to regulate the temperature sup-
plying the radiant circuits. Failure to comply could
result in substantial property damage.
Use Figure 9 or Figure 10 only for systems designed
for return water at least 130 °F. For systems with
low return water temperature, such as converted
gravity systems and radiant heating systems, install
bypass piping (see
page 15
) to protect boiler against
condensation. Failure to prevent low return water
temperature to the boiler could cause corrosion of
the boiler sections or burners, resulting in severe
personal injury, death or substantial property dam-
age.
4 Install water piping
continued
