Water Piping — Refrigeration Systems; Prevent Chilled Water From Entering Boiler; Piping Refrigeration Systems - Williamson-Thermoflo GWA 3 Series Manual

3 Install water piping
Near-boiler piping
Figure 5
Diaphragm- or bladder-type expansion tank:
Piping to single-zone system using
diaphragm-type or bladder-type expansion
tank. See Table 4 for piping sizes.
Figure 6
Closed-type expansion tank: Piping to
single-zone system using closed-type
expansion tank. See Table 4 for piping sizes.
Part Number 550-142-320/0720
GWA Series 3 Gas-Fired Water Boilers – Boiler Manual
continued
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Use Figure 5 or Figure 6 only for systems designed
for return water at least 130 °F. For systems with low
return water temperature possible, such as converted
gravity systems and radiant heating systems, install
bypass piping (see page 12) 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 damage.
If system includes radiant heating circuits, provide
piping and controls to regulate the temperature
supplying the radiant circuits. Failure to comply could
result in substantial property damage.
Install boiler so that chilled medium is piped in parallel
with heating boiler (Figure 7). 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
automatic 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.
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 7 for typical installation of
balancing valve and check valve.
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 automatic means to prevent gravity circulation
during cooling cycle.
Figure 7

Piping refrigeration systems

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