Carrier BW9 Series Installation Instructions Manual page 7

FLOW CHECK VALVE
CIRCULATORS
PRESSURE
REDUCING VALVE
CAN VENT
EXPANSION TANK
ZONE SERVICE
VALVE
NOTE: When zoning with circulators, the furnished circulator pump should
be used as one of the zone pumps. Each stripped end of the electrical wires
for the circulator pump inside the junction box should be taped or wired
nutted to prevent short circuits. Unplug the circulator pump wiring at the
integrated boiler control.
Fig. 4 --- Multizone Boiler Piping with Circulators
3. Combustion air and vent piping connections on boiler are
2", but must increase to ( 3"). Due to potential for flue gas
temperatures over 155_F, the first 5 feet of vent pipe must
be CPVC, the remaining vent pipe can be PVC. If any
elbows are employed within the first 2- -1/2 feet of vent,
they must be CPVC. Two - - 30" pieces of 2" CPVC pipe
and one - - 2" CPVC coupling are furnished with the boiler.
NOTE: The exhaust transition from 2" pipe to 3" pipe must be
made in a vertical run. Transition pieces not included. (See Fig.
13.)
Combustion and Vent Pipe Lengths
The length of pipe is counted from the boiler jacket (air intake
pipe) or from vent tee (vent pipe). The first five feet of "Total
Equivalent Length" of vent pipe must be CPVC.
Boiler Size 3" Pipe Min.
Venting
125--- 200 6 ft in length +
4--- 90_ elbows
Reduce the maximum vent length 5 feet per each additional
elbow.
1. Combustion air and vent piping to be pitched back to
boiler at minimum 1/4" per foot from intake and vent
terminals so that all moisture in combustion air and vent
piping drains to boiler. Pipes must be pitched continuously
with no sags or low spots where moisture can accumulate
and block the flow of air or flue gas. Combustion air and
vent pipes must be airtight and watertight.
ZONE SERVICE
VALVE
SUPPLY TO
ZONES
ZONE SERVICE VALVE
FLOW CHECK
VALVE
GATE VALVE
REDUCED PRESSURE
FEED
BACKFLOW PREVENTER
WATER
RETURN FROM
ZONES
ZONE SERVICE
VALVE
A04052
3" Pipe Max.
60 ft in length and
up to 4--- 90_
elbows
Fig. 5 --- Relief Valve Discharge Piping
2. Consideration for the following should be used when
determining an appropriate location for termination of
combustion air and vent piping:
a. Comply with all clearances required as stated in
paragraph 3 below.
b. Termination should be positioned where vent vapors
will not damage plants/shrubs or air conditioning
equipment.
c. Termination should be positioned so that it will not be
affected by wind eddy, airborne leaves, snow, or
recirculated flue gases.
d. Termination should be positioned where it will not be
subjected to potential damage by foreign objects, such
as stones, balls, etc.
e. Termination should be positioned where vent vapors
are not objectionable.
f. Put vent on a wall away from the prevailing winter
wind. Locate or guard the vent to prevent accidental
contact with people or pets.
g. Terminate the vent above normal snowline. Avoid
locations where snow may drift and block the vent. Ice
or snow may cause the boiler to shut down if the vent
becomes obstructed.
h. Under certain conditions, flue gas will condense,
forming moisture, and may be corrosive. In such cases,
steps should be taken to prevent building materials at
the vent from being damaged by exhaust of flue gas.
7
PRESSURE
RELIEF DEVICE
A04053