Bryan Boilers Forced Draft Steam Boilers User Manual
Installation
Operation
Service Manual
for
Forced Draft Steam
Boilers
BRYAN BOILERS
783 N. CHILI AVENUE, PERU, INDIANA 46970
Telephone: 765-473-6651 / Fax: 765-473-3074
E-Mail: bryanboilers@iquest.net / Internet: www.bryanboilers.com
INSTALLATION INSTRUCTIONS
FORCED DRAFT
STEAM BOILERS
NOTE:
• Please read all of instruction manual before attempting installation.
• Insurance and local or state regulatory codes may contain additional or more stringent requirements
than those contained in this manual. Installation must conform to these codes and any other
authority having jurisdiction.
1.1 BOILER FOUNDATION
Before uncrating, the boiler location should be
prepared. The boiler should set upon a good level
concrete floor. If the boiler is not level or the floor
in good condition, a concrete foundation should
be built, the dimensions larger than the outside
dimensions of the boiler base.
DO NOT INSTALL BOILER ON COMBUSTIBLE
FLOORING. The only exception to this is UL
Labeled F -Series boilers which may be installed
on combustible flooring.
IMPORTANT
If the boiler is installed directly on a concrete floor
where it is important that the floor be kept cool
(such as an upper floor or mezzanine or when
sitting over wiring conduits) set the boiler up on
insulating tile or steel framework so that air may
circulate underneath. For atmospheric gas fired
boilers, it is advisable to build up an insulating
floor under the boiler using high temperature
mineral fiber board at least 1 1/2" thick.
1.2 CLEARANCES
See Table 1 for minimum clearances to wall,
ceilings, or obstructions. The clearances in Table
1 are intended as a general recommendation
only. Local codes must be applied to specific
installations and the minimum clearances
established accordingly. Provisions must also be
made for service, accessibility and clearance for
piping and electrical connections.
Do not obstruct combustion air and ventilation
openings with piping or any other construction. All
boilers must be installed in a space which is
large, compared to the boiler. Only UL Labeled FSeries boilers are suitable for installation on
combustible flooring.
NOTE
ADHERE TO ALL APPLICABLE LOCAL CODES
REGARDING BOILER INSTALLATION AND
CLEARANCES.
1.3 UNCRATING THE BOILER
Uncrate the boiler near its permanent location.
Leave it on the bottom crating until ready to place
permanently. Leave the plastic shroud on the
boiler until all piping work is complete, cutting
holes in the plastic for access to connections.
Remove the bolts attaching the boiler to the crate
at the underside of the bottom crating. Lift or slide
the boiler off of the bottom crating into position.
Be careful not to tip the boiler up on one corner or
side, which could cause damage to jacket.
MINIMUM CLEARANCES
NOTE: These boilers are intended to be installed in a room which is large compared to the size of
the boiler. They are not intended for alcove installation and are suitable for installation on noncombustible flooring only.
50#
WATER
/STEAM
TO 50#
STEAM
OVER
50#
1
DIMENSION
A 18" 36" 18" 48" 24" 24" 18" 36" 24" 24"
B 24" 24" 48" 96" 48" 36" 48" 24" 48" 48"
CV & CH 18" 36" 18" 36" 24" 24" 24" 24" 24" 24"
D 48" 96" 18" 36" 24" 24" 24" 24" 24" 24"
EL & ER 24" 24" 18" 36" 24" 24" 24" 24" 32" 32"
D-SERIES F-SERIES
WATER/
STEAM
TO 50#
STEAM
OVER
50#
WATER
/STEAM
TO 50#
CL-SERIES K-SERIES RV, RW & AB SERIES
STEAM
OVER
50#
WATER
/STEAM
TO 50#
STEAM
OVER
50#
WATER
/STEAM
TO 50#
STEAM
OVER
1 - F-Series boilers are approved for installation on combustible flooring. Do not install on carpeting.
A - Clearance above boiler
B - Front of boiler
C
C
- Clearance from gas vent, measured vertically above pipe
V
- Clearance from gas vent, measured horizontally or below pipe
H
D - From back of boiler
E
E
- Left side of boiler
L
- Right side of boiler
R
These clearances are general minimum clearances. Local codes may dictate larger clearances.
1.4 BOILER CONNECTIONS
1.4.1 GENERAL
Do not run any pipes along the access panel
side of the boiler. Maintain clearances as
shown on the dimensional drawing for
servicing of the boiler tubes. Provide at least
36" from the gas train and burner, unless a
larger dimension is indicated on the
dimensional. All piping should be designed
and installed to avoid any loadings on the
boiler connections or piping.
1.4.2 STEAM SUPPLY CONNECTION
A steam shut-off valve must be installed
between each boiler and the steam main.
This valve must be of the outside screw and
yoke design to allow indication from a
distance whether the valve is open or closed.
1.4.3 FEEDWATER CONNECTION
Install a check valve and a globe valve
between the feed pump and the boiler. It is
also recommended to install a globe valve
between the feed pump and the receiver
tank. This valve can then be adjusted to
bypass excess pump capacity to better
control the boiler feed rate.
1.4.4 SAFETY RELIEF VALVE(S)
A connection is provided in the top of the
boiler for the relief valve. The relief valve
discharge piping must be the same size as
the relief valve discharge opening. Avoid
over-tightening as this can distort valve seats.
All piping from relief valve must be
independently supported with no weight
carried by the valve.
1.4.4 BLOWDOWN CONNECTION
Blowdown valve(s) must be full size of the
connection on the boiler. Steam boilers 15
psig and below require at least one blowdown
valve. Higher pressure boilers require two
blowdown valves with one or both valves
being slow opening type. Each water column
and float type low water cut-off must be
equipped with a blowdown valve.
1.5 GAS SUPPLY CONNECTION - FORCED DRAFT UNITS
The installation must conform completely to the
requirements of the authority having jurisdiction,
or in the absence of such, requirements shall
conform in the U.S. to the current National Fuel
Gas Code, ANSI Z223.1-1984, or in Canada to
the current Installation Code for Gas Burning
Appliances and Equipment (CAN/CGA B149.1M91), or Oil Burning Equipment (CSA B139M91), and applicable regional regulations for the
class; which should be followed carefully in all
cases.
1.5.1 DRIP LEG
A drip leg or sediment trap must be installed in
the gas supply line. See Fig. 1.5A. The gas line
must be connected to a supply main at least as
large as the gas train connection at the boiler.
This connection should be made with a union so
that the boiler gas train components and burner
may be easily removed, if necessary, for service.
1.5.2 GAS PIPING LEAK TEST
After completion of the gas piping hookup, the
installation must be checked for leaks, using a
soap and water solution. Disconnect the boiler
and gas train from the gas supply piping during
any pressure testing of the gas supply system.
Drip leg
must be installed on gas supply piping.
Consult the local gas utility company
inspection and authorization of all gas supply
piping and flue connections.
The regulator vent line must be vented to outside
of building on any boiler equipment with electric
gas pilot ignition.
1.5.3 VENTING OF GAS TRAIN COMPONENTS
Gas pressure regulator - The regulator must be
vented to the outside air, using minimum 1/4"
tubing or pipe. The vent line should terminate in a
downward direction to be free of restriction.
Diaphragm gas valves (V48A or V88A) - The vent
line off of these gas valves must be vented to
outdoors, the same as the regulator.
Normally open vent valves - These valves must
be piped to outdoors using pipe no smaller than
that of the valve.
Gas pressure switches - Vent these switches to
outdoors using a minimum of 1/4" tubing or
piping.
for
FIGURE 1.5A: GAS BURNER CONNECTION
NOTE: USE PIPE COMPOUND, WHICH IS RESISTANT TO THE ACTION OF LIQUID PETROLEUM
GAS. DO NOT USE TEFLON TAPE.
1.6 ELECTRICAL CONNECTION
IMPORTANT: All electrical connections must
conform to the National Electrical Code and to all
other applicable State and Local Codes. Forced
draft boilers may require a high voltage
connection. See boiler wiring diagram and
equipment list for
details.
Equipment Grounding
grounded in accordance with the American
National Standard Electrical Code, ANSI/NFPA
#70-1981.
- The boiler must be
1.7 COMBUSTION AIR SUPPLY
IMPORTANT: Positive means for supplying an
ample amount of outside air, allowing complete
combustion of the gas, must be provided.
Movable combustion air dampers, automatic or
manually adjustable, must be electrically
interlocked with the boiler to prevent boiler
operation if the dampers are closed.
Combustion air openings must never be blocked
or obstructed in any manner.
The boiler room must be at a positive or neutral
pressure relative to the outdoors. A negative in
the boiler room will result in downdraft problems
and incomplete combustion due to lack of air.
WARNING!
Failure to provide an adequate air supply will
result in boiler damage and hazardous conditions
in the building (fire and asphyxiation hazard as
well as equipment damage).
COMBUSTION AIR:
natural or propane gas requires approximately
ten cubic foot of air (at sea level and 70F) for
each 1000 Btu of boiler input. In reality, additional
air is required to achieve complete combustion.
Air is also required for the proper operation of the
appliance draft diverter or barometric damper.
The combustion air opening recommendations
below are designed to provide the air needed for
atmospheric gas fired boilers which are equipped
with either draft diverters or barometric dampers.
Combustion air openings for boilers which are
equipped with forced draft burners may be
reduced to 70% of that required for atmospheric
gas fired boilers. This is because the forced draft
Complete combustion of
boiler is not equipped with a draft control device
(so no air is required for draft control).
COMBUSTION AIR OPENINGS - AREA
REQUIRED:
Openings directly through outside wall
One opening within 12 inches of the ceiling plus
one opening within 12 inches of the floor. Each
opening must have a minimum free area of 1
square inch per 4,000 Btu of total input of all air
using appliances in the room.
Example: A boiler room having two boilers with
500,000 Btu input would require two openings
through an outside wall, and each opening must
have at least 250 square inches of free area.
Openings through vertical ducts
One duct in the ceiling plus one duct terminating
within 12 inches of the floor. Each opening must
have a minimum free area of 1 square inch per
4,000 Btu of total input of all air-using appliances
in the room.
Example: A boiler room having four boilers with
250,000 Btu input would require two ducts, one in
the ceiling and one terminating near the floor,
each opening having at least 250 square inches
of free area.
Openings through horizontal ducts
One duct opening within 12 inches of the ceiling
plus one duct opening within 12 inches of the
floor. Each opening must have a minimum free
area of 1 square inch of per 2,000 Btu of total
input for all equipment in the room. NOTE: No
rectangular duct may have a dimension of less
than 4 inches.
Example: A boiler room having 1 million Btu total
input would require two ducts, one in the ceiling
and one near the floor, each opening must having
at least 500 square inches of free area.
-
-
-
Ventilation Air: In addition to air needed for
combustion, sufficient air must be supplied for
ventilation, including air required for comfort and
proper working conditions for personnel in the
boiler room. In colder climates, provision should
also be made to heat the boiler room, if
necessary, for personnel comfort.
CAUTION
Protection from combustion air contamination:
disposal. The boiler room and the combustion air
supply must not be exposed to the fumes. Such
fumes include, but are not limited to, carbon
monoxide, hydrogen sulfide, ammonia, chlorine,
and halogenated hydrocarbons.
NOTE: Halogenated hydrocarbons are
particularly injurious and corrosive after exposure
to high temperatures.
Where corrosive or flammable process fumes are
present in the vicinity of the boiler room or the air
stream for the combustion air supply, it is
essential that suitable means be provided for their
safe
1.8 CHIMNEY, FLUE PIPE & DRAFT CONTROL - FORCED DRAFT BOILERS
CODE COMPLIANCE
The installation must conform to the requirements
of NFPA 54, the National Gas Code (ANSI
Z223.1-1984), Part 7, "Venting of Equipment", or
to the applicable requirements of all local building
codes. For factory-built and listed chimney
systems (such as type B vent), consult the
system manufacturer's instructions for correct
installation procedures. Gas vents may be of any
of the construction types listed in this manual. No
portion of a venting system may extend into or
pass through any circulating air duct or plenum.
MINIMUM SAFE PERFORMANCE
Venting systems must be designed to develop
positive flow adequate to remove flue gases to
the outside atmosphere. Guidelines are provided
in this manual and in the National Fuel Gas Code,
NFPA 54, for sizing and design of flue gas
venting systems. For additional reference to good
practice in vent design, refer to the "Chimney,
Gas Vent, and Fireplace Design" chapter of the
ASHRAE Equipment Handbook.
OUTSIDE VENTS AND CHIMNEYS
Outside uninsulated single wall pipe is not
recommended for use in cold climates for venting
gas-fired appliances since temperature
differentials may cause corrosion in such pipe, as
well as poor draft on start ups. When local
experience indicates that condensate may be a
problem, provisions should be made to drain off
the condensate in the gas vent or chimney.
ESTIMATING FLUE GAS FLOW RATE
Flue gas volumetric flow rate in SCFM (standard
cubic feet per minute) and ACFM (actual cubic
feet per minute) can be estimated by using the
information in 1.8.1A. Divide the Total Input of
appliances connected to the chimney or vent by
1000. Then multiply this result times the factor
listed in the SCFM and ACFM table. The ACFM
data is required for determining stack exit velocity
and induced draft fan requirements.
ESTIMATING STACK EXIT VELOCITY
First, determine the ACFM for the stack as
described above. Multiply the total ACFM times
the Velocity Factor from the Velocity Table in
Table 1.8.1B for the stack diameter used. The
result is the Stack Exit Velocity in feet per second.
ESTIMATING STACK EMISSIONS
Table 1.8.1C lists approximate emissions of NOx
(oxides of nitrogen) and CO (carbon monoxide).
The table lists both the concentration, in parts per
million (ppm), and the flow rate, in pounds per
hour (PPH), of each compound: Divide the total
input of appliances connected to the chimney or
vent by 1,000,000. Then multiply this result times
the value listed in the table for PPH emissions.
MANUAL REFERENCES
See Figure 1.8.1 for a graphics listing of
applicable sections of this manual for each
section of the vent system.
(ACFM)
FIG. 1.8.1: VENT DESIGN INSTRUCTION -
REFERENCES
TABLE 1.8.1A: ESTIMATING FLUE GAS VOLUMETRIC FLOW RATE
Approximate Flue Gas VOLUMETRIC FLOW RATE
(Per 1000 Btu/hr Input)
(Multiply factor listed times boiler input in MBH)
BOILER TYPE
Water & 15# Steam
Gas Fired
Oil Fired
150# Steam
Gas Fired
Oil Fired
SCFM Per
1000 Btu/hr
INPUT
0.230
0.230
0.230
0.230
ACFM Per
1000 Btu/hr
INPUT
0.402
0.402
0.425
0.425
APPROXIMATE
TEMPERATURE
TABLE 1.8.1B: STACK EXIT VELOCITY
Estimated STACK EXIT VELOCITY Calculation
(Multiply total ACFM times the velocity factor below velocity in feet per second)
STACK INSIDE
DIAMETER (Inches)
6
7
8
10
12
14
16
VELOCITY
FACTOR
0.0849
0.0624
0.0477
0.0306
0.0212
0.0156
0.0119
STACK INSIDE
DIAMETER (Inches)
18
20
22
24
26
28
32
VELOCITY
FACTOR
0.00943
0.00764
0.00631
0.00531
0.00390
0.00340
0.00298
FLUE GAS
450F
450F
500F
500F
STACK INSIDE
DIAMETER (Inches)
34
36
38
40
48
60
VELOCITY
FACTOR
0.00264
0.00236
0.00212
0.00191
0.00133
0.00085
TABLE 1.8.1C: ESTIMATING FLUE GAS EMISSIONS
Estimated Emissions (Volumetric Flow Rate Per Million Btu/hr Input)
(Multiply PPH listed times boiler input divided by 1,000,000)
BOILER
TYPE
Gas Fired
Oil Fired
PARTICULATES NOx CO SOx Hydrocarbons
PPH per
MMBH
N/A
0.020
PPM
N/A
20
PPH per
MMBH
0.049
0.068
PPM
50
70
PPH per
MMBH
0.194
0.018
PPM
200
18
PPH per
MMBH
N/A
0.286
PPM
1.8.2 CLEARANCES
The vent system and draft control devices must
be installed so as to achieve the clearances to
surfaces outlined in Table 1.2.1, Minimum
Clearances chart, in this manual. See also Table
1.8.9 for vent clearances. All clearances must
local and state building codes. The clearances
described in this manual are intended to be
general guidelines only, additional requirements
may occur because of local building design
regulations.
comply with the National Fuel Gas Code
(NFPA54), and with all
1.8.3 BOILER ROOM PRESSURIZATION
The boiler room must be supplied with adequate
air for combustion and for proper operation of
diverters) as outlined in "Combustion Air Supply",
Section 1.7 of this manual.
draft control devices (barometric dampers or draft
WARNING
THE BOILER ROOM MUST BE MAINTAINED
AT A POSITIVE OR NEUTRAL PRESSURE
(RELATIVE TO OUTDOORS) AT ALL TIMES.
EXHAUST FANS OR CONNECTIONS FROM
THE BOILER ROOM TO ZONES OF NEGATIVE
PRESSURE (AIR DUCTS, NEGATIVE
PRESSURE ROOMS, ETC.) WILL CAUSE
NEGATIVE PRESSURE IN THE BOILER
ROOM. SUCH CONDITIONS WILL CAUSE
HAZARDOUS OPERATION OF THE BOILER
AND INTRODUCTION OF COMBUSTION
PRODUCTS INTO THE BUILDING AIR.
IF THE BOILER ROOM MUST BE UNDER A
NEGATIVE PRESSURE AT ANY TIME, AN
INDUCED DRAFT FAN WILL BE REQUIRED.
FURTHER, THE BOILER MUST BE PROVIDED
WITH A BAROMETRIC DRAFT CONTROL -
NOT WITH A DRAFT DIVERTER. THE FAN
MUST BE INTERLOCKED WITH THE BOILER
AND A DRAFT PROVING SWITCH MUST BE
INSTALLED TO PREVENT OPERATION OF
THE BOILER IF THE FAN SHOULD FAIL TO
OPERATE.
IT ALSO MAY BE ADVISABLE TO INSTALL AN
AUTOMATIC VENT DAMPER IN THE VENT
SYSTEM TO PREVENT BACKFLOW
THROUGH THE VENT SYSTEM DURING
BOILER OFF CYCLES. SEE FOLLOWING
SECTION ON AUTOMATIC VENT DAMPERS.
N/A
290
PPH per
MMBH
0.010
0.004
PPM
10
4
1.8.7 ACCEPTABLE VENT TYPES
LISTED GAS VENTS
Listed gas vents must be applied only on those
applications for which they are listed. Type B gas
vents are NOT listed for use on forced draft
appliance vent systems.
Installation of these vents must comply with the
vent listing, with the vent manufacturer's
instructions and with complete adherence to the
codes and clearances as outlined previously.
PRESSURIZED VENT SYSTEMS
Some Bryan Boilers (unless specifically fitted for
the application) are not suitable for operation on a
pressurized vent systems. Refer to Section 2 of
this manual for the allowable range of vent
pressure for each series. The RV, RW, and AB
series boilers are designed for pressurized vent
systems. All others require a neutral pressure.
SINGLE-WALL METAL PIPE
Single-wall metal pipe must be of galvanized
sheet or other approved non-combustible
corrosion resistant material, with minimum
thickness per Table 1.8.7, from the National Fuel
Gas Code. Single-wall metal pipe should be
insulated to prevent excessive heat in the boiler
room and to avoid ignition and spillage problems
as well as corrosion from excessive
condensation.
MASONRY, METAL AND FACTORY BUILT
CHIMNEYS
Installation of factory built vents and chimneys
must comply with the vent listing, with the vent
manufacturer's instructions and with adherence to
the codes and clearances as outlined herein.
Masonry or metal chimneys must be built and
installed in accordance with nationally recognized
building codes or standards.
MASONRY CHIMNEYS FOR RESIDENTIAL
APPLICATIONS MUST BE LINED WITH FIRE-
CLAY FLUE LINING (KX C315 OR THE
EQUIVALENT) WITH THICKNESS NOT LESS
THAN 5/16 INCH OR WITH A LINER OF OTHER
APPROVED MATERIAL THAT WILL RESIST
CORROSION, SOFTENING OR CRACKING
FROM FLUE GASES AT TEMPERATURES UP
TO 1800F.
EXISTING CHIMNEYS SHOULD BE
INSPECTED FOR UNSAFE CONDITIONS,
SUCH AS DETERIORATED MASONRY AND
EXCESSIVE SOOT OR OTHER BLOCKAGE OR
POTENTIAL BLOCKAGE. SEE ALSO SECTION
1.8.6.
EXISTING CHIMNEYS MUST BE PROPERLY
SIZED FOR THE FLUE GAS LOADING TO BE
USED. THAT IS, IF AN EXISTING CHIMNEY IS
USED FOR A SMALLER TOTAL INPUT THAN
ITS ORIGINAL DESIGN, A LINER OR VENT IS
REQUIRED. THE USE OF A PROPERLY SIZED
GAS VENT OR LINER WILL PREVENT
DETERIORATION OF THE CHIMNEY DUE TO
THE EXCESSIVE CONDENSATION WHICH
RESULTS ON OVERSIZED SYSTEMS.
WARNING
UNDER NO CIRCUMSTANCES SHOULD THE
FLUE PIPE BE CONNECTED TO THE
CHIMNEY OF AN OPEN FIREPLACE.
TABLE 1.8.7A
WATER BOILER & STEAM BOILERS TO 50 PSIG
Diameter of
Connector, Inches
Minimum Thickness,
Inch (Gauge)
6 to 10 0.023 (24) 14 and less 0.053 (16)
10 to 12 0.029 (22) 14 to 16 0.067 (14)
12 to 16 0.034 (20) 16 to 18 0.093 (12)
16 + 0.056 (16) 18 + 0.123 (10)
TABLE 1.8.7B
(STEAM BOILERS OVER 50 PSIG)
Diameter of
Connector, Inches
Minimum Thickness,
Inch (Gauge)
1.8.5 VENT CONNECTORS (HORIZONTAL RUNS)
CONSTRUCTION
Vent connectors may be of any of the acceptable
constructions listed in this manual.
AVOID UNNECESSARY BENDS
The vent connector must be installed so as to
avoid turns or other construction features which
create excessive resistance to flow of flue gases.
JOINTS
Vent connectors must be firmly attached to draft
diverter outlets or boiler flue collars by sheet metal
screws or other approved means. Vent connectors
of Type B vent material must be assembled in
accordance with the vent manufacturer's
instructions. Joints between sections of connector
piping must be fastened using sheet metal screws
or other approved means.
SLOPE OR VENT CONNECTOR
The vent connector must be installed without any
dips or sags and must slope upward at least 1/4
inch per foot.
LENGTH OF VENT CONNECTOR
The vent connector must be as short as possible
and the boiler as close as practical to the chimney
or vent.
The horizontal run of an uninsulated vent
connector to a natural draft chimney or vent
servicing a single appliance must not be more than
75% of the height of the chimney or vent above
the vent connector.
The horizontal run of an insulated vent connector
to a natural draft chimney or vent servicing a single
appliance must not exceed 100% of the height of
the chimney or vent above the vent connector.
SUPPORT OF VENT CONNECTOR
The vent connector must be supported in
accordance with the vent manufacturer's
instructions and listing and with all applicable
codes. Support should also be independent of the
boiler or the draft diverter (when used). The vent
connector must be supported for the design and
weight of the material employed to maintain
clearances, prevent physical damage and
separation of joints, and to prevent sagging of the
vent connector.
Supports should usually be overhead hangers, of
load bearing capacity appropriate for the weight
involved.
LOCATION
When the vent connector used for an appliance
having a draft hood must be located in or pass
through a crawl space or other area difficult to
access or which may be cold, that portion of the
vent connector must be of listed double wall Type
B gas vent material, or of material having
equivalent insulation qualities. Single wall metal
pipe used as a vent connector must not pass
through any floor or ceiling.
CHIMNEY CONNECTION
In entering a passageway in a masonry or metal
chimney, the vent connector must be installed
above the extreme bottom to avoid stoppage.
Means must be employed which will prevent the
vent connector from protruding so far as to restrict
the space between its end and the opposite wall of
the chimney. A thimble or slip joint may be used to
facilitate removal of the vent connector. The vent
connector must be firmly attached to or inserted
into the thimble or slip joint to prevent the vent
connector from falling out.
DAMPERS
Manually operated dampers must not be placed in
the vent connector. This does not exclude the use
of fixed baffles, locking quadrant dampers which
are welded in a fixed position, or automatic vent
dampers (when properly installed and interlocked
with the boiler gas controls).
USE OF THIMBLES
Vent connectors made of single wall metal pipe
must not pass through any combustible wall
unless they are guarded at the point of passage by
ventilated metal thimbles 6" larger in diameter than
the vent connector. This may be done only on
water boilers and steam boilers rated for operation
at no higher than 50 psig.
SINGLE WALL METAL VENT PIPE USED TO
VENT STEAM BOILERS OPERATING OVER 50
PSIG MUST NOT PASS THROUGH WALLS OR
PARTITIONS CONSTRUCTED OF
COMBUSTIBLE MATERIAL.
1.8.6 CHIMNEY & VENT CONSTRUCTION (VERTICAL SECTION)
INSTALLATION OF FACTORY BUILT
SYSTEMS
Listed gas vents and factory built chimneys must
be installed in accordance with their listings and
the manufacturer's instructions. Vents and
venting systems passing through roofs must
extend though the roof flashing, roof thimble or
roof jack.
INSTALLATION OF MASONRY OR METAL
CHIMNEYS
Masonry or metal chimneys must be built in
accordance with nationally recognized building
codes and standards.
INSTALLATION OF SINGLE WALL GAS VENTS
Single wall metal pipe may be used only for runs
directly from the space in which the appliance is
located through the roof or exterior wall to the
outer air. A pipe passing through a roof must
extend without interruption through the roof
flashing, roof jack or thimble. Single wall metal
pipe must not originate in any unoccupied attic or
concealed space. Additionally, it must not pass
through any attic, inside wall, concealed space or
through any floor. Minimum clearance must be
maintained between the single wall metal pipe
and any combustible surface as outlined in Table
1.8.9.
When a single wall metal pipe passes through an
exterior wall constructed of combustible material,
it must be guarded at the point of passage by a
ventilated thimble as described under "Use of
Thimbles" in Section 1.8.8 of this manual.
Alternatively, a non-ventilating thimble not less
than 18" above and 6" below the roof (with the
annular space open at the bottom and closed at
the top) may be used.
INSPECTIONS OF CHIMNEYS
Before connection of a vent connector to a
chimney, the chimney passageway must be
examined to ascertain that it is clear and free of
obstructions. Cleanouts must be constructed
such that they will remain tightly closed when not
in use. Tee fittings used as cleanouts or
condensate drains must have tight fitting caps to
prevent entrance of air into the chimney at such
points. When an existing masonry chimney is
unlined and local experience indicates that vent
gas condensate may be a problem, an approved
liner or another vent must be installed. When
inspection reveals that an existing chimney is not
safe for the intended application, it must be rebuilt
to conform to nationally recognized standards,
relined with a suitable liner, or replaced with a gas
vent or chimney suitable for the appliances to be
attached.
SUPPORT OF CHIMNEYS AND VENTS
All portions of chimneys must be adequately
supported for the design and weight of the
materials employed. Listed factory built chimneys
must be supported and spaced in accordance
with their listings and the chimney or gas vent
manufacturer's recommendations.
THE GAS VENT OR CHIMNEY MUST BE
SUPPORTED INDEPENDENTLY OF THE
BOILER TOP OR DRAFT DIVERTER.
EQUIPMENT TYPE
Listed Vent Single Wall Metal Pipe Factory Built Chimney
Water and 15 psig Steam Boilers not permitted 18" as listed
All Steam Boilers over 15 psig not permitted 36" as listed
MINIMUM REQUIRED DISTANCE FROM COMBUSTIBLE MATERIAL
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