Williamson Series 2 - Page 14

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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.
 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