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C: Standard Piping Installation Requirements
Observe the following requirements when installing the boiler piping:
1) Relief Valve (Required) – The relief valve is shipped loose and must be installed in the location shown in Figure
9.9,usingthesideoutletTeeandotherttingsprovided.ASMESectionIVcurrentlyrequiresthatthisrelief
valve be installed above the heat exchanger as shown. Pipe the outlet of the relief valve to a location where water
or stream will not create a hazard or cause property damage if the valve opens. The end of the discharge pipe must
terminate in unthreaded pipe. If the relief valve discharge is not piped to a drain, it must terminate at least 6” above
theoor.Donotrunthedischargepipingthroughanareathatispronetofreezing.Theterminationoftherelief
valve must be in an area where it is not likely to become plugged by debris.
The relief valve supplied with the boiler is set to open at 30 psi. If it is replaced, the replacement must have
a setting less than or equal to the maximum allowable working pressure (MAWP) shown on the ASME data plate
located on the left side of the heat exchanger behind the service access panel (Figure 9.9).
2) Gauge (Required) - Indicates supply water pressure and temperature. This gauge is shipped loose. Install it as shown
in Figure 9.9.
3) Circulator (required) – The boiler loop circulator is factory installed inside the boiler cabinet. Usually at least
one addition circulator (not supplied) will be required for the system to work properly. See the previous section for
more information.
4) Expansion Tank (required) – If this boiler is replacing an existing boiler with no other changes in the system,
the old expansion tank can generally be reused. If the expansion tank must be replaced, consult the expansion tank
manufacturer’sliteratureforpropersizing.
5) FillValve(required)–Eitheramanualorautomaticllvalvemaybeused,butamanualvalveispreferredbecause
iteliminatesunmonitoredadditionsofmake-upwatertothesystem.Theideallocationforthellvalveisatthe
expansion tank.
6) Automatic Air Vent (required) – At least one automatic air vent is required. Manual air vents will usually be required
inotherpartsofthesystemtoremoveairduringinitialll.
7) Manual Reset High Limit (required by some codes) - This control is required by ASME CSD-1 and some
other codes. Install the high limit in the boiler supply piping just above the boiler with no intervening valves. Set
the manual reset high limit to 200°F. Wire the limit per Figure 10.2 in the Wiring section.
8) Isolation Valves (recommended) - Isolation valves are useful when the boiler must be drained, as they will eliminate
havingtodrainandrelltheentiresystem.
9) Strainer (recommended) – Install a Y Strainer, or other suitable strainer, to prevent any system debris from entering
theboilerandfoulingthewaterpassages.Notethatsomestrainershaveasignicantpressuredrop,whichmay
impacttheabilityoftheboilerpumptoobtaintherequiredow.SeesectionBforadditionalinformation.