Bryan Boilers Boiler 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: [email protected] / Internet: www.bryanboilers.com

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 non-

combustible flooring only.

D-SERIES

F-SERIES¹

CL-SERIES

K-SERIES

RV, RW & AB SERIES

DIMENSION

WATER/

STEAM

OVER

50#

WATER

STEAM

OVER

50#

WATER

STEAM

OVER

50#

WATER

STEAM

OVER

50#

WATER

/STEAM

TO 50#

STEAM

OVER

50#

STEAM

TO 50#

/STEAM

TO 50#

/STEAM

TO 50#

/STEAM

TO 50#

18"

24"

18"

48"

24"

36"

24"

36"

96"

24"

18"

48"

18"

48"

96"

36"

24"

48"

24"

36"

24"

18"

48"

24"

36"

24"

48"

24"

32"

24"

48"

24"

32"

C_V& C_H

E_L& E_R

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_V- Clearance from gas vent, measured vertically above pipe

C_H- Clearance from gas vent, measured horizontally or below pipe

D - From back of boiler

E_L- Left side of boiler

E_R- Right side of boiler

These clearances are general minimum clearances. Local codes may dictate larger clearances.

1.4 BOILER CONNECTIONS

1.4.1 GENERAL

tank. This valve can then be adjusted to

bypass excess pump capacity to better

control the boiler feed rate.

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.

1.4.4 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.

1.4.2 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.

1.4.4 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.

1.4.3 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

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 B149.1-

M91), or Oil Burning Equipment (CSA B139-

M91), and applicable regional regulations for the

class; which should be followed carefully in all

cases.

Drip leg must be installed on gas supply piping.

Consult the local gas utility company for

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.

1.5.1 DRIP LEG

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.

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.

Diaphragm gas valves (V48A or V88A) - The vent

line off of these gas valves must be vented to

outdoors, the same as the regulator.

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.

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.

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

details.

Equipment Grounding - The boiler must be

grounded in accordance with the American

National Standard Electrical Code, ANSI/NFPA

#70-1981.

draft boilers may require

high voltage

connection. See boiler wiring diagram and

equipment list for

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.

boiler is not equipped with a draft control device

(so no air is required for draft control).

COMBUSTION AIR OPENINGS

REQUIRED:

AREA

Movable combustion air dampers, automatic or

manually adjustable, must be electrically

interlocked with the boiler to prevent boiler

operation if the dampers are closed.

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.

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.

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.

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: Complete combustion of

natural or propane gas requires approximately

ten cubic foot of air (at sea level and 70 F) 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

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.

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.

CAUTION

Protection from combustion air contamination:

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

ESTIMATING FLUE GAS FLOW RATE (ACFM)

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.

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.

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.

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.

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.

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.

MANUAL REFERENCES

See Figure 1.8.1 for a graphics listing of

applicable sections of this manual for each

section of the vent system.

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)

SCFM Per

1000 Btu/hr

INPUT

ACFM Per

1000 Btu/hr

INPUT

APPROXIMATE

FLUE GAS

BOILER TYPE

TEMPERATURE

Water & 15# Steam

Gas Fired

0.230

0.402

450 F

Oil Fired

150# Steam

Gas Fired

0.230

0.425

500 F

Oil Fired

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

VELOCITY

FACTOR

STACK INSIDE

VELOCITY

FACTOR

STACK INSIDE

VELOCITY

FACTOR

DIAMETER (Inches)

0.0849

0.0624

0.0477

0.0306

0.0212

0.0156

0.0119

0.00943

0.00764

0.00631

0.00531

0.00390

0.00340

0.00298

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

PARTICULATES

NOx

SOx

Hydrocarbons

PPH per

MMBH

PPM

PPH per

PPM

PPH per

MMBH

PPM

PPH per

PPM

PPH per

PPM

MMBH

Gas Fired

Oil Fired

N/A

0.049

0.194

0.018

200

N/A

290

0.010

0.020

0.068

0.286

0.004

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

comply with the National Fuel Gas Code

(NFPA54), and with all

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.

1.8.3 BOILER ROOM PRESSURIZATION

The boiler room must be supplied with adequate

air for combustion and for proper operation of

draft control devices (barometric dampers or draft

diverters) as outlined in "Combustion Air Supply",

Section 1.7 of this manual.

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

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.

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.

IT ALSO MAY BE ADVISABLE TO INSTALL AN

AUTOMATIC VENT DAMPER IN THE VENT

SYSTEM

PREVENT

BACKFLOW

IF THE BOILER ROOM MUST BE UNDER A

NEGATIVE PRESSURE AT ANY TIME, AN

THROUGH THE VENT SYSTEM DURING

BOILER OFF CYCLES. SEE FOLLOWING

SECTION ON AUTOMATIC VENT DAMPERS.

1.8.7 ACCEPTABLE VENT TYPES

LISTED GAS VENTS

installed in accordance with nationally recognized

building codes or standards.

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.

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 1800 F.

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.

EXISTING

CHIMNEYS

SHOULD

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.

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

WARNING

UNDER NO CIRCUMSTANCES SHOULD THE

FLUE PIPE BE CONNECTED TO THE

CHIMNEY OF AN OPEN FIREPLACE.

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

TABLE 1.8.7A

TABLE 1.8.7B

WATER BOILER & STEAM BOILERS TO 50 PSIG

(STEAM BOILERS OVER 50 PSIG)

Diameter of

Connector, Inches

Minimum Thickness,

Inch (Gauge)

Diameter of

Connector, Inches

Minimum Thickness,

Inch (Gauge)

6 to 10

10 to 12

12 to 16

16 +

0.023 (24)

0.029 (22)

0.034 (20)

0.056 (16)

14 and less

14 to 16

16 to 18

18 +

0.053 (16)

0.067 (14)

0.093 (12)

0.123 (10)

1.8.5 VENT CONNECTORS (HORIZONTAL RUNS)

CONSTRUCTION

Supports should usually be overhead hangers, of

Vent connectors may be of any of the acceptable

constructions listed in this manual.

load bearing capacity appropriate for the weight

involved.

AVOID UNNECESSARY BENDS

LOCATION

The vent connector must be installed so as to

avoid turns or other construction features which

create excessive resistance to flow of flue gases.

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.

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.

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.

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.

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.

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.

SINGLE WALL METAL VENT PIPE USED TO

VENT STEAM BOILERS OPERATING OVER 50

PSIG MUST NOT PASS THROUGH WALLS OR

PARTITIONS

CONSTRUCTED

COMBUSTIBLE MATERIAL.

1.8.6 CHIMNEY & VENT CONSTRUCTION (VERTICAL SECTION)

INSTALLATION

SYSTEMS

FACTORY

BUILT

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.

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.

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.

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.

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.

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.

THE GAS VENT OR CHIMNEY MUST BE

SUPPORTED INDEPENDENTLY OF THE

BOILER TOP OR DRAFT DIVERTER.

MINIMUM REQUIRED DISTANCE FROM COMBUSTIBLE MATERIAL

EQUIPMENT TYPE

Listed Vent

not permitted

Single Wall Metal Pipe

Factory Built Chimney

as listed

Water and 15 psig Steam Boilers

All Steam Boilers over 15 psig

18"

36"

as listed

1.8.7 MARKING OF GAS VENTS

In those localities where solid and liquid fuels are

used extensively, gas vents must be plainly and

permanently identified by a label reading:

"This gas vent is for appliances which

burn gas only. Do not connect to

incinerators or solid or liquid fuel burning

appliances."

The authority having jurisdiction must determine

whether their area constitutes such a locality.

This label must be attached to the wall or ceiling

at a point near where the gas vent connector

enters the wall, ceiling or chimney.

1.8.8 VENTING MULTIPLE APPLIANCES ON A COMMON VENT

COMMON GAS VENT

PRESSURIZED

CONNECTORS

DO NOT CONNECT THE FLUE OF AN

APPLIANCE VENTED BY NATURAL DRAFT TO

A VENT SYSTEM WHICH OPERATES UNDER

A POSITIVE PRESSURE.

VENTS

VENT

When two or more openings (for vent connectors)

are provided in a chimney or gas vent, the

opening should be at different levels. They should

never be opposite one another.

When two vent connectors enter the same gas

vent or chimney, the smallest of the two should

enter at the highest position possible.

SOLID FUEL APPLIANCE VENTS

Gas appliances must not be vented to a vent or a

chimney which serves a solid fuel burning

appliance.

1.8.9 VENT AND CHIMNEY TERMINATIONS

HEIGHT ABOVE ROOF OR OBSTACLE

WATER BOILERS AND LOW PRESSURE

STEAM BOILERS: No less than 3 feet above the

roof and no less than 2 feet above any parapet or

obstacle closer than 10 feet from the vent outlet.

CLEARANCE FROM PUBLIC WALKWAYS

The vent exit of a mechanical draft system must

be at least 7 feet above grade when located next

to public walkways.

HIGH PRESSURE (OVER 15 PSIG) STEAM

BOILERS: No less than 10 feet higher than any

portion of any building within a distance of 25 feet

from the vent.

PROTECTION OF BUILDING MATERIALS

FROM

POSSIBLE

CORROSION

DISCOLORATION FROM FLUE PRODUCTS

The products of combustion from gas or oil

contain potentially corrosive gases and high

temperatures. For this reason, the chimney or

vent exit must be designed to prevent exposure

of the building materials to the flue products.

Failure to do so may result in deterioration or

discoloration of building materials.

MINIMUM HEIGHT ABOVE DRAFT CONTROL

Chimneys and gas vents must extend at least 5

feet above the highest connected barometric draft

control or any appliance flue outlet.

CLEARANCE FROM AIR INLETS

The vent or chimney must terminate no less than

3 feet above any forced air inlet within a distance

of 10 feet. It must terminate no less than 1 foot

above, or 4 feet below, or 4 feet horizontally from,

any door, window or gravity air inlet into a

building.

VENT SUPPORT

The gas vent or chimney must be securely

positioned and supported. Guy wires or other

reliable means must be used to prevent

movement of the vent.

PROTECTION AGAINST BLOCKAGE OR

OBSTRUCTION

The chimney or vent exit design must prevent any

possibility of blockage by snow or any other

obstruction.

Listed gas vents must be terminated with a listed

cap, approved for use with the particular gas

vent.

Listed vent caps or roof assemblies must have a

rated venting capacity no less than the vent.

VENTILATING

SYSTEMS

HOODS

AND

EXHAUST

Single wall vents must terminate in an approved

cap which does not obstruct the exit. The

preferred type of cap for natural draft vented

atmospheric boilers is the Briedert Cap. This is

because of the protection this cap provides

against wind-generated downdrafts.

Ventilating hoods or exhaust systems may be

used to vent atmospheric gas appliances. When

these are used, however, such mechanical

exhaust devices must be electrically interlocked

with all appliances on the vent system. The circuit

must prevent the operation of any appliance on

the system if the hood or exhaust system is not in

operation.

Where there is no concern of high winds or

turbulence at the vent exit, a low resistance

conical cap may be used. See Fig. 1.8.12B for

typical dimensions. The diameter of this type cap

should be twice the vent diameter. The cap must

be securely positioned on the vent such as to

provide a clearance of one vent diameter above

the vent exit.

STACK CAPS

EVERY GAS VENT MUST BE SUPPLIED WITH

AN APPROVED VENT CAP WHICH WILL

PREVENT THE ENTRANCE OF RAIN OR

OTHER PRECIPITATION INTO THE VENT.

FAILURE TO PROVIDE SUCH A CAP MAY

CAUSE SEVERE BOILER CORROSION,

COMBUSTION PROBLEMS, OR BOTH.

FIG. 1.8.12B: LOW RESISTANCE VENT CAP

1.8.10 AUTOMATIC VENT DAMPERS

ONE APPLIANCE ONLY

INSTALLATION

An automatic vent must be installed such that it

serves only one appliance vent - that to which it is

properly interlocked.

The damper installation must comply with

Appendix I, J, or K of the National Fuel Gas

Code, NFPA 54. The installation must also

comply with the automatic vent damper listing,

the damper manufacturer's instructions and all

applicable local or state building codes.

LISTING REQUIREMENTS

Automatic vent dampers, if used, must be of a

listed type.

AUTOMATIC VENT DAMPERS MUST BE

INSTALLED ONLY BY QUALIFIED SERVICE

TECHNICIANS. FAILURE TO PROPERLY

INSTALL A VENT DAMPER WILL CREATE A

SEVERE HAZARD.

PERFORMANCE TEST

The automatic vent damper must be tested after

installation to assure its proper and safe

operation.

AUTOMATIC VENT DAMPERS MUST BE IN

THE OPEN POSITION AT ANY TIME THE

APPLIANCE MAIN GAS VALVE IS ENERGIZED.

1.8.14 SIZING OF CHIMNEY AND VENT

IMPORTANT

the gas input. Consult the factory or the local

Bryan Representative for the proper parts. For

the purpose of vent system sizing, assume full

input and determine sizing as if at sea level. The

derate factor of 4% per 1000 feet above sea

level accounts for the increased volume per

Btu/hr of flue products at high altitude.

The flue system calculations which follow in

Section 1.8.15 are applicable to double-wall or

insulated single wall breechings (vent connectors)

and stacks (vents). Do not apply these

calculations to uninsulated vent systems.

HIGH ALTITUDES

At altitudes of 2000 feet and higher, atmospheric

boilers must be derated. The amount of derate

required by the National Fuel Gas Code is 4% per

1000 feet above sea level. Boilers which are

shipped from the factory prepared for these

altitudes have the gas orifices properly sized for

this derate. The altitude and gas Btu content for

which the boilers have been constructed is listed

on the Equipment List/Submittal Data in the boiler

manual. The boilers will also be provided with a

label indicating that they have been prepared for

high altitude. If a boiler is to be installed at an

altitude other than that for which it was factory

built, orifices must be replaced to properly adjust

INDUCED DRAFT FANS

Occasionally, the characteristics of an installation

are such that a natural draft vent system will not

suffice. In such cases, induced draft may be

used. The vent system is then sized with an

available "pumping" action equal to the total

theoretical draft plus the static pressure capability

of the induced draft fan. This will result in a

smaller diameter vent than for a natural draft

system. Sizing of induced draft fans should be

done using the recommendations of the fan

manufacturer and the ASHRAE Handbook.

FIG. 1.8.14: SUGGESTED APPLIANCE VENTING PROCEDURE

MULTIPLE APPLIANCE INSTALLATIONS

individual venting is not possible, boilers may be

vented to a common breeching (vent connector).

See Fig. 1.8.14B for recommended design of

such a system. Note that connections of

individual boiler or appliance vents into the

common breeching should

Bryan recommends that boilers and other gas

appliances be individually vented when possible.

See figure 1.8.14A. Individual venting provides

better draft control and fuel efficiency, and is less

likely to cause condensation in the system. When

be done with 45

elbows and not by

provide a relatively constant flue gas velocity

through the vent system. Using a constant

diameter breeching will often result in poor draft

at the outermost appliances.

"bullheading" directly into the vent connector at

90 angles. "Bullhead" connections generally

cause excessive turbulence and poor draft

conditions. On vent connectors serving multiple

appliances, the diameter of the piping should be

increased at each appliance's entrance so as to

1.8.12 QUICK SELECTION FOR VENT SIZING CHARTS

GENERAL

must be checked against such local

These charts were generated using the

procedure described in Chapter 26 of the

ASHRAE Equipment Handbook (1979). The

results are consistent with those of the National

Fuel Gas Code.

requirements.

RECTANGULAR VENTS

Vent systems may be rectangular as well as

circular. Table 1.8.15F has been provided to give

the circular equivalent of rectangular duct. These

equivalent values account for the higher pressure

drop per cross section area for rectangular ducts.

The sizing herein is applicable to vent systems

utilizing double wall listed Type B vent as well as

single wall insulated vent with insulation

equivalent to double wall insulating value.

STEP 1: EQUIVALENT INPUT

CONTROL FACTOR

DRAFT

Determine the boiler (system) Draft Control

This sizing procedure is not applicable to vent

systems utilizing single wall uninsulated vents or

vent connectors.

Factor, F¹, from Table 1.8.15A.

Determine the boiler (or total system) input in

MBH. This is done by dividing the boiler (or total

system) input in Btu/hr by 1000.

The sizing information given herein is intended as

a general recommendation only. Vent sizing and

installation must comply with local codes.

Multiply the total input times factor F₁.

The responsibility for assurance of such

compliance is that of the system designer and/or

the system installer. All sizing and installation

The equivalent input, I, (without altitude

correction) is then:

I = MBH x F₁

eq. 15A

TABLE 1.8.15A: DRAFT CONTROL FACTOR F₁

Multiply factor time input in MBH

Boiler Type

Factor, F₁

1.000

Atmospheric with Draft Hood

Atmospheric with Barometric

Forced Draft Gas or Oil

0.741

0.602

STEP 2: EQUIVALENT INPUT - ALTITUDE

FACTOR

Determine the boiler (system) Altitude Correction

Factor, F₂, from Table 1.8.15B.

The altitude correction factor, F₂for atmospheric

boilers is equal to 1, because their inputs are

already derated for altitude.

The equivalent input, I, with corrections for

altitude is:

Multiply the boiler (or total system) input times

factors, F₂and F₁for the equivalent input.

I = MBH x F₁x F₂

eq. 15B

Table 1.8.15B ALTITUDE CORRECTION FACTOR, F₂

(Multiple factor times sea level input, MBH)

Altitude (ft)

Factor, F₂

Altitude (ft)

Factor, F₂

0 to 1999

2000

2500

3000

3500

4000

4500

5000

5500

1.00

1.075

1.096

1.116

1.136

1.157

1.180

1.202

1.25

6000

6500

7000

7500

8000

8500

9000

10000

1.247

1.272

1.296

1.322

1.346

1.373

1.399

1.453

STEP 3: SELECT TRIAL DIAMETER

STEP 4: CALCULATE SYSTEM K-FACTOR

The system "k-factor" accounts for the pressure

drop through fittings and vent piping. It is

calculated by adding up the individual k-factors

for each of the fittings plus the k-factor for the

vent pipe(s).

Determine the NET STACK HEIGHT for the vent.

(The net stack height is the vertical distance from

the top of the atmospheric boiler draft control to

the top of the stack. On forced draft boilers it is

the distance from the boiler flue connection to the

top of the stack.)

From Table 1.8.15D find the k-factors for each of

the elbows, tee fittings, draft regulators, etc. in the

system. Then calculate the vent piping k-factor

from the formula:

Find the vent of TRIAL STACK DIAMETER. Enter

Table 1.8.15C at the Net Stack Height column

equal to the system net stack height. Then

proceed down the column to the input which is

just larger than the equivalent to an input which is

just larger than the Equivalent Input of the

system. Read the Trial Stack Diameter in the left

hand column.

k_piping= 0.4 x L/D

eq. 15C

L = total length of piping in feet

D = diameter of piping in inches

Add all the k-factors together to determine the

total system k-factor:

k_total= k_piping+ k_fittings

eq. 15D

NOTE: This is only a trial diameter. Proceed to

Step 4 to calculate the system k-factor to

determine the actual stack diameter required.

NOTE: On multiple appliance systems, multiply

the k-factor times 1.5. This is required only on

atmospheric boiler vent systems, not on forced

draft systems.

Table 1.8.15D: Vent Fitting k-Factors

Vertical Draft Hood

Barometric Draft Control

1.50

0.50

Low Resistance Cap

Round Elbow, 90 deg F

Round Elbow, 45 deg F

0.75

0.30

Converging Exit

Cone

(D1/D2)⁴- 1

(D1 is larger than D2)

Tee or 90 degF Breeching

Y Breeching

1.25

0.75

Tapered Reducer

1 - (D2/D1)⁴

(D1 is larger than D2)

STEP 5: CORRECT EQUIVALENT INPUT FOR

SYSTEM K-FACTOR

Multiply the equivalent input calculated in Step 2

times factor F₃from Table 1.8.15E. This step will

yield a new equivalent input, I:

The capacities listed in Table 1.8.15C are based

on a system k-factor equal to 7.5. For any other

k-factor, the vent capacity must be adjusted. This

is accomplished by adjusting the equivalent input

for the system using a k-factor correction factor,

designated F₃.

I = MBH x F₁x F₂x F₃eq. 15E

Using this adjusted equivalent input, check the

stack diameter by following Steps 2 thru 3 again.

If the stack diameter remains the same, the sizing

is complete. If not, redo Steps 4 thru 5 etc. until

Refer to Table 1.8.15E for the equivalent input

correction factor which applies to the k-factor

calculated in Step 4. This factor is designated as

F₃.

acceptable

result

achieved.

Table 1.8.15E: K-Factor Equivalent Input Correction Factor F₃

K- Factor F₃K- Factor F₃K- Factor F₃

K- Factor F₃

1.00 0.37

1.50 0.45

2.00 0.52

2.50 0.58

3.00 0.63

3.50 0.68

4.00 0.73

4.50 0.77

5.00 0.82

5.50

6.00

6.50

7.00

7.50

8.00

8.50

9.00

9.50

0.86

0.89

0.93

0.97

1.00

1.03

1.06

1.10

1.13

10.00

10.50

11.00

11.50

12.00

12.50

13.00

13.50

14.00

1.15

1.18

1.21

1.24

1.26

1.29

1.32

1.34

1.37

14.50

15.00

15.50

16.00

16.50

17.0

17.50

18.00

18.50

1.39

1.41

1.44

1.46

1.48

1.51

1.53

1.55

1.57

19.00

19.50

20.00

20.50

21.00

21.50

22.00

22.50

23.00

1.59

1.61

1.63

1.65

1.67

1.69

1.71

1.73

1.75

Stack

Diam.

(in.)

Table 1.8.15C: Approximate Stack Capacities (MBH)

(Based on Atmospheric Boiler with Draft Hood)

150

280

320

100

450

125

510

150

550

200

640

100

120

140

170

200

220

250

270

300

350

380

400

430

130

160

190

210

240

270

310

340

360

390

410

430

480

510

550

580

620

690

760

870

180

210

250

280

310

360

400

440

480

510

540

570

620

670

720

760

810

900

990

1140

1450

1790

2580

3510

4590

5810

7170

8680

10330

12120

14060

16140

18360

20730

23240

41320

52290

64560

92970

220

270

320

350

390

450

510

560

600

640

680

720

790

850

910

970

1020

1260

1820

2480

3240

4100

5070

6130

7300

8570

9940

11410

12980

14650

16430

29210

36970

45650

65740

1140

1410

2040

2770

3620

4590

5670

6860

8160

9580

11110

12760

14510

16390

18370

32660

41340

51040

73500

1250

1550

2330

3040

3970

5030

6210

7510

8940

10490

12170

13970

15900

17950

20120

35780

45290

55910

80510

280

330

400

430

490

560

630

690

750

800

850

890

980

1060

1520

2070

2710

3430

4240

5130

6110

7170

8310

9540

10860

12260

13750

24400

30930

38190

55000

1130

1630

2220

2900

3670

4530

5480

6530

7660

8890

10200

11610

13110

14700

26130

33070

40830

58800

1200

1730

2350

3070

3890

4810

5820

6920

8130

9430

10820

12310

13900

15590

27710

35080

43310

62360

400

480

570

630

700

810

910

1000

1360

1770

2250

2770

3360

4000

4690

5440

6250

7110

8020

9000

1080

1470

1920

2430

3000

3630

4320

5070

5880

6750

7680

8670

9720

1150

1570

2050

2590

3200

3880

4610

5420

6280

7210

8210

9270

10390

1220

1660

2170

2750

3400

4110

4900

5750

6660

7650

8710

9830

1290

1750

2290

2900

3580

4340

5160

6060

7030

8070

9180

10360

1410

1920

2510

3180

3920

4750

5650

6640

7700

8840

10050

11350

12730

22630

28640

35360

50920

550

650

780

860

960

1110

1450

1830

2260

2740

3260

3830

4440

5100

5800

6550

7350

1240

1620

2050

2530

3060

3650

4280

4970

5700

6490

7320

8210

720

850

1020

1290

1600

1940

2300

2710

3140

3600

4100

4630

5190

9230

1120

1420

1750

2120

2530

2960

3440

3950

4490

5070

5670

10120

1250

1590

1960

2370

2820

3320

3850

4420

5020

5670

6360

910

1080

1340

1620

1930

2260

2630

3010

3430

3870

4340

7730

1130

1370

1630

1910

2220

2550

2900

3270

3670

6530

8260

10200

14700

11020 11620

19600 20660

24800 26140

30620 32280

44100 46480

11310 13060 14600 16000 17280 18470

14320 16530 18480 20250 21870 23380

17680 20410 22820 25000 27000 28870

25460 29400 32870 36000 38890 41570

9780 11690 12810

12070 14430 15810

17390 20780 22770

NOTE: The above vent input capacities in MBH (thousands of Btu/hr) are sea level ratings for double wall or insulated vents allowing for a system K factor of

7.5. Apply the correction factors for altitude, other k-factors and boiler draft control correction factors.

Table 1.8.15F: CIRCULAR EQUIVALENTS OF RECTANGULAR BREECHINGS & STACKS

WIDTH

HEIGHT (INCHES)

(INCHES)

10 12 14 16

10 10

10 11 11 12

10 11 12 13 14

11 12 13 14 15

10 11 13 14 15 16

10 12 14 15 16 17

11 13 15 16 17 19

11 13 15 17 18 20

12 14 16 18 19 20

12 15 17 18 20 21

13 15 17 19 21 22

13 16 18 20 21 23

14 16 18 20 22 24

15 17 20 22 24 26

16 19 21 23 26 28

17 20 22 25 27 29

17 21 23 26 29 31

18 21 24 27 30 32

1.8.16 SPECIAL APPLICATIONS

FLUE GAS ECONOMIZERS

HIGH EFFICIENCY APPLIANCES

When applying flue gas economizers, care must

be taken to assure that:

1. Proper draft must be maintained. This requires

that the gas side pressure drop be considered

and that the economizer exchanger must be

designed so as to allow cleaning.

2. The vent system materials must be considered,

regarding resistance from corrosion, which might

result from the lower flue gas temperature.

3. In general, it is recommended that the boiler

manufacturer be consulted when a flue gas

economizer is to be added.

High efficiency appliances require special

consideration in vent design because of the

reduced stack gas temperatures. Under no

circumstances can a condensing type appliance

be vented into the same vent system with other

appliances. The vent system for such appliances

must be provided by or specified specifically by

the manufacturer of the condensing appliance.

High efficiency non-condensing appliances

should

generally be installed only on vent

systems that are resistant to corrosion from flue

gas condensate. This generally requires stainless

steel vent construction.

1.9 BURNERS AND GAS TRAIN - FORCED DRAFT BOILERS

GENERAL

Oil supply lines must be sized for the circulation

Refer to separate manual on the forced draft

burner for start-up and adjustment procedures.

Do not attempt to start burner when excess oil

has accumulated, or when the combustion

chamber is full of gas, or if chamber is very hot.

rate of the burner pump. This is referred to as the

suction gear capacity of the pump. If a transfer

pump is used, it must have a pumping capacity

no less than the total suction gear capacity of all

burner pumps on the system. Refer to Burner

Manual for the suction gear capacity of standard

oil pumps. Two-pipe oil systems are

recommended in all cases, although a one-pipe

system might be acceptable on smaller boilers

(under 6 gph). Two-pipe systems tend to have

fewer problems with air entrainment in the oil. Air

in the oil will cause nuisance problems and

delayed ignition.

FUEL CONNECTIONS

Gas supply connections must comply with the

National Fuel Gas Code (NFPA54). Oil supply

connections must comply with NFPA31. Any

additional local or state codes must also be

adhered to.

1.10 PROCEDURES TO BE FOLLOWED BEFORE PLACING BOILER IN

OPERATION

1.10.1 HYDROSTATIC TEST OF BOILERS AND

SYSTEM

although the boiler is hydrostatically tested at the

factory, minor leaks in fittings and at attachments

can develop from shipping vibration or from

installation procedures. It is often necessary to

retighten such fittings after the installation and

after the boiler has been operated for some time.

Replace tube access panels before proceeding to

start boiler.

After completing the boiler and burner installation,

the boiler connections, fittings, attachments and

adjacent piping must be inspected for leaks by

filling the unit with water. The pressure should be

gradually increased to a pressure just below the

setting of boiler safety relief valve(s).

Remove the boiler tube access panels (see

dimensional drawing in this manual). Inspect the

tube to header joints to be certain that all tube

fittings are sealed. This is necessary because,

1.10.2 TEST OF GAS PIPING

Reference gas system test under Section 1.5,

"Gas Connection", in this manual.

START-UP AND OPERATION

STEAM BOILERS

WARNING:

IMPROPER SERVICING AND START-UP OF THIS EQUIPMENT MAY CREATE A

POTENTIAL HAZARD TO EQUIPMENT AND TO OPERATORS OR PERSONS IN THE

BUILDING.

SERVICING AND START-UP MUST BE DONE ONLY BY FULLY TRAINED AND

QUALIFIED PERSONNEL.

CAUTION:

BEFORE DISCONNECTING OR OPENING ANY FUEL LINE, OR BEFORE CLEANING OR REPLACING

PARTS OF ANY KIND, TAKE THE FOLLOWING PRECAUTIONS:

Turn OFF the main fuel shutoff valves, including the pilot gas cock if applicable. If the burner is a multiple

fuel type, shut OFF all fuel supplies.

Turn OFF all electrical disconnects to the burner, boiler and any other equipment or systems electrically

interlocked with the burner or boiler.

All cover plates, enclosures, and guards must be in place at all times except during maintenance and

servicing.

2.1 FIRING RATE ADJUSTMENT - ATMOSPHERIC GAS UNITS

2.1.1 The following procedures must be followed

carefully before putting the boiler in operation.

Failure to do so will present severe hazards to

equipment, operating personnel and building

occupants.

which firing rate system is used, see the boiler

Equipment List and Wiring Diagram.

2.1.4 ADJUST BOILER MINIMUM INPUT

After setting the correct Maximum input as

described in the Lighting Instructions, proceed to

adjust the minimum input as outlined below. This

applies only to those boilers which are designed

and equipped for two-stage (High/Low/Off) firing

or Modulation. On those boilers which are

equipped for ON/OFF firing only, no minimum

input adjustment is required. NOTE: the low firing

rate input is adjustable only on boilers equipped

with two-stage or modulating motorized gas

valves (V4055, V9055, or AH4 actuators) or with

motor-operated modulating butterfly gas valves.

The other two-stage firing systems (VR850 or

VR852 combination valves or dual diaphragm

valve type bypass systems) have a non-

adjustable minimum input rate.

2.1.2 ADJUST PILOT BURNER

Carefully follow the Lighting Instructions in the

boiler manual for the proper adjustment of the

pilot burner. This is absolutely essential before

attempting to adjust the main burner.

2.1.3 ADJUST BOILER INPUT(S)

The boiler input must be adjusted for both

maximum and minimum input values which are

listed on the boiler nameplate. First adjust the

maximum input rating using the method

described in Lighting Instructions in the Boiler

Manual. Refer to the following information for the

adjustment of the minimum input. To determine

the adjustment

NOTE

2.1.6 MINIMUM INPUT ADJUSTMENT - DUAL

DIAPHRAGM GAS VALVE HIGH/LOW BY-PASS

SYSTEM

THE LOW FIRE ADJUSTMENT SHOULD

RESULT IN A GAS PRESSURE ON THE

BURNER MANIFOLD EQUAL TO 1" WATER

COLUMN FOR NATURAL GAS AND 3" FOR

PROPANE GAS.

The minimum input on this control system is NOT

adjustable. The maximum input must be properly

set as outlined in Lighting Instructions. This

system consists of two V48A (120 volt coil) or two

V88A (24 volts coil) diaphragm gas valves which

are piped in parallel. The minimum input is

controlled by an orifice plug installed in a coupling

in the by-pass piping (low fire valve piping), sized

for approximately 1" w.c. manifold pressure at low

fire natural gas (2" w.c. if propane gas). When the

high fire gas valve is not activated, gas flows only

through the bypass piping. When the high fire gas

valve is activated, gas will flow though both

valves achieving full input.

2.1.5 MINIMUM INPUT ADJUSTMENT

COMBINATION GAS VALVES (VR850 OR

VR852)

The minimum input on these gas valves is NOT

adjustable. The maximum input must be properly

set as outlined in Lighting Instructions. See the

manufacturer's instructions on the VR850 or

VR852 included in the Boiler Manual for further

information.

2.2 FIRING RATE ADJUSTMENT - GAS METER READINGS

2.2.1 CHECKING BURNER INPUT

calculated from this timing. The method is

The burner input rate can be checked by taking

readings from the gas meter. Please note

checking the rate with a meter is the only way to

be sure of input. Manifold readings are only an

approximate value and may vary from unit to unit.

described in Lighting Instructions. If the meter is

not calibrated for gas temperature and pressure,

correction factors must be applied to determine

correct rate in SCFH (standard cubic feet per

hour). Consult the National Fuel Gas Code (ANSI

Z223.1, NFPA 54) or the local gas utility for

further information. Refer to Table 2.2A for

correction factors for the gas pressure at the

meter. Refer to Table 2.2B for the gas

temperature correction factors.

In order to obtain accurate data, there must be no

other appliances using gas from the same meter

while the burner input rate is being checked. The

test hand on the meter should be timed for

several revolutions. The input rate in cubic feet

per hour is

Table 2.2A - Pressure Correction

Table 2.2B - Temperature Correction

Gas Pressure at Meter

7" w.c.

Correction Factor

Gas Temp. at Meter

Correction Factor

0.920

1.017

1.034

1.051

1.061

1.136

1.340

14" w.c.

0.902

21" w.c.

0.885

1 psig

0.868

2 psig

0.852

5 psig

0.836

2.3 SAFETY SHUT-OFF DEVICES (FLAME SUPERVISION)

2.3.1 FLAME SUPERVISORY SYSTEM

flame loss. In addition to the information given in

The boiler is equipped with a flame supervisory

system, either the Thermocouple type (such as a

combination gas valve or a pilotstat) or electronic

type (such as the RA890, or RM7895). The

purpose of this device is to detect the main or

pilot flame, depending on the type of device, and

control the gas valves accordingly. The device

must be checked for proper operation. See

Lighting Instructions in the Boiler Manual for the

correct procedure. The flame supervisory system

must be tested to assure that it will shut off the

main gas valves in case of a

Lighting Instructions, operating sequence and

troubleshooting information may be found in the

manufacturer's instructions in the Boiler Manual.

2.3.2 AUTOMATIC (ELECTRIC) IGNITION

SYSTEMS

On boilers equipped with automatic electrically

ignited pilots, follow the procedures described in

Lighting Instructions and test the controls for

proper operation.

2.4 LIMIT CIRCUIT CUT-OUT TEST

2.4.1 PROTECTIVE DEVICES

All operating and limit controls and low water

cutoffs must be tested for proper operation.

water feeder combination) or electric probe type

auxiliary control. These water level controls are

intended to sense (and control) the level of the

water in the boiler. They operate to shut off the

boiler if the water level drops below their sensing

level. The low water cut-off and water level

controls must be operationally tested by manually

lowering the boiler water level (by opening the

boiler blowdown valve for probe controls, and by

opening the control blowdown valve for float type

controls). The boiler should cycle off when the

water level drops below the control point of the

low water cut-off. When the water level is

restored, the boiler should cycle back on.

Depress the manual reset button of devices

which require manual reset in order to restore the

boiler to operation. Carefully read the enclosed

literature on the low water cut-off controls,

particularly installaing, operating and servicing.

2.4.2

STEAM

PRESSURE

OPERATING

CONTROL

The steam pressure in the boiler is regulated by

the Boiler Operator. This is a pressure control

which senses the steam pressure and turns the

boiler on and off accordingly. This control must be

operationally tested. Adjust the pressure setting

on the control to a pressure less than the boiler

pressure (as shown on the boiler pressure

gauge). The control should turn the boiler off.

Restore the control setting to normal. The boiler

should cycle on.

2.4.3 HIGH LIMIT CONTROL

At least one additional pressure control is

provided as the high limit control. It is set at a

pressure above the operator to act as a back-up

should the operator fail. The high limit control

must be operationally tested. With the boiler

operating, decrease the pressure setting of the

limit control below the current pressure of the

boiler. The boiler should cycle off. Restore the

high limit control setting to normal (pushing rest

button if it is a manual reset type). The boiler

should now cycle on.

2.4.5 COMBINATION LOW WATER CUT-OFF &

FEEDER

The low water cut-off/feeder supplied with some

boiler serves as a low water cut-off (see above)

and also causes make-up water to be added to

the boiler should the water level drop below its

control point.

This type of control must be operationally tested

as for low water cut-offs and also to assure that

the make-up water is introduced as needed.

Carefully read the enclosed literature on the Low

2.4.4 LOW WATER CUT-OFF(S)

Most boilers are supplied with a float-operated

primary low water cut-off (and pump control or

Water Cut-off controls, particularly installing,

operating and servicing.

2.4.7 BOILER FEED SYSTEM

The boiler feed pump must be operationally

tested to assure that it can provide boiler

feedwater at the pressure and in the amount

needed for safe and reliable boiler operation.

2.4.6 OTHER CONTROLS

Additional controls as required for the particular

installation may also be provided. Refer to the

literature on these devices included in the Boiler

Manual. All such devices must be operationally

tested to assure reliable operation of the boiler

and system.

2.4.8 CHEMICAL FEED SYSTEM & SOFTENER

Check the performance of the boiler water

softener and chemical treatment system.

Chemically test the feedwater to be certain it

complies with the recommendations of the

chemical treatment consultant.

2.5 RECOMMENDED DRAFT AND COMBUSTION READINGS

ATMOSPHERIC GAS-FIRED BOILERS

BOILER SERIES

DRAFT AT BOILER CO₂@ HIGH

O₂@

HIGH FIRE

(ppm)

SMOKE

NO.

OUTLET

(i.w.c.)

FIRE

-0.01 TO -0.04

-0.02 TO -0.04

-0.02 TO -0.06

7.5 TO 8.5 % 5.0 TO 7.5 %

7.5 TO 9.0 % 4.8 TO 7.5 %

8.0 TO 9.5 % 4.0 TO 6.7 %

< 400

FORCED DRAFT GAS FIRED BOILERS

BOILER SERIES

DRAFT AT

BOILER

CO₂@

HIGH FIRE

O₂@

HIGH FIRE

(ppm)

SMOKE

NO.

OUTLET (i.w.c.)

HED

-0.01 TO -0.04

0.0 TO -0.04

7.5 TO 9.5 %

4.0 TO 7.5 %

< 400

8.5 TO 10.0 % 3.2 TO 5.0 %

9.0 TO 10.0 % 3.2 TO 5.0 %

HECL

RV & RW

0.0 TO -0.06

+0.50 TO -0.10

+0.25 TO -0.06

FORCED DRAFT OIL FIRED BOILERS

BOILER SERIES

DRAFT AT

BOILER

CO₂@

HIGH FIRE

O₂@

HIGH FIRE

(ppm)

SMOKE

NO.

OUTLET (i.w.c.)

-0.01 TO -0.04

0.0 TO -0.04

10.0 TO 12.0 % 4.0 TO 7.2 %

11.5 TO 12.5 % 3.7 TO 5.0 %

< 400

RV & RW

+0.50 TO -0.10

+0.25 TO -0.06

NOTE: THE VALUES FOR CO₂AND O₂ARE SHOWN FOR HIGH FIRE ONLY. THE VALUES FOR LOW

FIRE OR MID RANGE WILL GENERALLY BE LOWER, PARTICULARLY FOR ATMOSPHERIC GAS-

FIRED BOILERS. DRAFT SHOULD BE MEASURED APPROXIMATELY 24" FROM TOP OF BOILER,

BEFORE ANY DRAFT CONTROL.

2.5.1 DRAFT ADJUSTMENT - ATMOSPHERIC

GAS BOILERS

ARE MADE TO ASSURE ADEQUATE DRAFT

THROUGH THE VENTING SYSTEM.

2.5.2 DRAFT ADJUSTMENT -FORCED DRAFT

BOILERS

Draft adjustments are generally not necessary on

forced draft boilers. The draft must be measured

as part of the start-up procedure. The measured

draft at the boiler flue should fall within the

recommended range specified in the appropriate

table.

Refer to Section 1.8.6 for the adjustment method

for barometric dampers. Adjust the damper so as

to yield a draft which results in values of CO₂and

CO within the allowable limits listed above in the

appropriate table.

Draft adjustments are generally not required for

boilers equipped with draft diverters. The diverter

must

installed

without

modification.

Combustion readings are required, however, to

assure that the boiler operation is both safe and

efficient.

On some installations the draft may be excessive

due to a high chimney. In these cases, the draft

should be adjusted within the recommended

range specified in the above appropriate table.

This may be done using a barometric damper, a

restrictor, or a locking quadrant damper. Such

devices must be installed and adjusted by a

qualified technician.

Draft measurement should preferably be made

with an inclined tube manometer. If a draft gauge

is not available, check to be sure the flue gases

are being carried up the venting system by

passing a lighted taper or match around the edge

of the draft hood relief opening (or barometric). If

the venting system is operating correctly, the

match flame will be drawn toward the draft hood

relief opening. Otherwise the products of

combustion will tend to push the flame and

extinguish it.

2.5.3

COMBUSTION

ADJUSTMENTS

FORCED DRAFT

Refer to the separate burner manual for the

procedures for burner adjustments. The burner

must be adjusted for smooth lightoff. Combustion

parameters should be within the range specified

in the above appropriate table. In no case should

the level of CO be allowed to exceed the limit

given, and the smoke spot reading must also not

exceed the value shown.

CAUTION

IF THE PRODUCTS OF COMBUSTION ARE

BEING EMITTED INTO THE ROOM (VENTING

SYSTEM NOT OPERATING CORRECTLY),

THE BOILER MUST NOT BE OPERATED

UNTIL PROPER ADJUSTMENTS OR REPAIRS

2.6 OPERATING INSTRUCTIONS

2.6.1 FAMILIARIZATION WITH MANUAL(S)

The user of the boiler must familiarize himself

with this manual and the burner manual for forced

draft boilers to be sure he is prepared to operate

and maintain the boiler properly.

The operating instructions should be kept in the

pocket in the boiler for F Series boilers, or

adjacent to the boiler for all others.

READ THE MANUAL BEFORE ATTEMPTING A

START UP.

2.7 MAINTENANCE SCHEDULE

2.7.1 POSTING SCHEDULE

Post a maintenance schedule in accordance with

the recommendations in this manual. A copy of a

typical schedule is included in this manual.

Section 3

CARE AND MAINTENANCE

STEAM BOILERS

CAUTION:

•

The boiler area should be kept free of combustible materials, gasoline and other flammable liquids.

The boiler and venting system must be kept free of obstructions of the air louvers and draft hood

relief openings.

•

The following procedures must be conducted as outlined to assure safe operation of the boiler.

All cover plates, enclosures, and guards must be in place at all times except during maintenance

and servicing.

3.1 REQUIRED PRECAUTIONS DURING TEMPORARY USE

GENERAL

1. Knowledge of burner/boiler operation.

A boiler is often utilized in new construction to

assist in curing of building components or to

provide temporary heat for the construction crew

or for other purposes during the time the building

is under construction. If precautions are not taken

during this time to protect the boiler, a great deal

of damage can occur before the ultimate owner

takes over the building.

2. Possession and understanding of boiler/burner

operating instruction manual.

3. Assurance that the boiler is fed with only

treated water at all times and that chemical

treatment and blowdown procedures are always

followed.

It is the mutual responsibility of the installing

contractor and the boiler owner to consider the

effect of temporary usage on the boiler warranty.

The following should be observed so as to assure

the longevity of the boiler.

4. Notification to the manufacturer (or

manufacturer's agent) to provide start-up services

if the boiler was purchased with start-up by a

factory representative.

5. Adherence to all of the start-up procedures

noted in the boiler/burner manual.

OPERATOR SKILLS/RESPONSIBILITIES

During the temporary use period, a single

individual must be assigned responsibility for the

care and operation of the boiler. This person's

responsibility must include, but not be limited to,

the following:

6. Considerations of warranty should the boiler be

used for temporary heat without adherence to the

recommended start-up and operating procedures

outlined in the instruction manuals.

3.2 CLEANING THE BOILER AND SYSTEM - NEW SYSTEMS

BOIL OUT PROCEDURE

In combination with system contamination,

The internal surfaces of a newly installed boiler

will have oil, grease or other protective coatings

used in manufacturing. Such coatings must be

removed since these coatings lower the heat

transfer rate and could lead to overheating of a

tube and reduce operating efficiency. Before

boiling out procedures may begin, the burner

must be ready for firing. The operator must be

familiar with the procedure outlined in the

boiler/burner operating instruction manuals.

bacteria may cause objectionable odors,

sometimes resembling natural gas. It is important

to keep these fumes from air intakes which would

distribute them throughout the building. On steam

humidification systems this is especially critical.

Consult your local water treatment chemist for

further information.

CAUTION

6. Fill the boiler with clean softened water until the

water level reaches the upper header. Then add

the cleaning solution into the upper header. Add

more clean water until the boiler is completely

filled. The water used for this initial fill should be

at room temperature, and must be softened as

noted.

The boil out procedure outlined must be

performed by, or under the direct supervision of,

a qualified technician. The chemicals used

present a hazard of burns and physical injury if

mishandled. Always use suitable face mask,

goggles, protective gloves and garments when

handling caustic chemicals. Do not permit the

chemical to come into contact with skin or

clothing. Always follow the safety precautions on

the container's label. Add chemicals slowly and in

small amounts to prevent excessive heat and

agitation. Do not add water to acid. Do not add

water to dry chemical. This will cause splattering

and/or explosion and severe risk of personal

injury.

7. After filling, fire the boiler intermittently (at low

fire) at a frequency as necessary to hold the

boiler solution at boiling point temperature. DO

NOT PRODUCE STEAM PRESSURE. Boil the

water, supervised at all times, for at least five

hours.

8. After the five hour boil out, begin to add a small

amount of fresh softened water so as to create a

slight overflow of the overflow pipe. This will carry

out impurities which have accumulated at the

water surface. Continue to apply heat and

overflow until the water emitted from the overflow

pipe clears. Then shut off burner.

Boiling out under pressure is not recommended.

If boil out under pressure is required, competent

assistance must be provided.

Your water consultant or water treatment

company will be able to recommend a cleaning or

boil out procedure. In the event that such service

is unavailable or as yet not selected, the following

may be used.

9. Let the boiler cool to 120 F or less. Then drain

the boiler. Use caution that the water is

discharged with safety.

10. Remove the inspection/cleanout openings in

the boiler upper and lower headers and wash the

waterside surfaces thoroughly using high

pressure water stream.

1. The boil out of the boiler and system is neither

difficult nor expensive. The chemicals needed for

cleaning are readily available. Trisodium

phosphate, and sodium hydroxide (lye) are the

most commonly used chemicals. Use only one

type of solution in the system. The amount of

chemical required will vary according to

conditions, but an amount of one pound of

chemical per fifty gallons of water is suggested.

11.

Inspect the boiler's internal (waterside)

surfaces thoroughly after the procedure. If the

surfaces are not clean, repeat the boil out.

12. After boil out, close all openings. Install relief

valves, gauge glasses and other components as

necessary. Completely fill the boiler with fresh,

softened, ambient temperature water. Fire the

boiler at low fire until water temperature of at least

180 F is reached. This will drive off dissolved

gases.

2. Before introducing the solution into the boiler,

an overflow pipe should be attached to the top of

the boiler and routed to a safe point of discharge.

3. Remove all safety valves to ensure that none

of the solution will come into contact with the

valve seats. Use care in removing and reinstalling

valves.

13. The boiler is now ready to operate.

4. All valves in the piping to and from the system

must be closed to prevent the chemical solution

from getting into the system.

IMPORTANT

If boiler is not to be operated within 24 hours, a

lay-up procedure is required. Refer to instruction

for lay-up.

5. Gauge glasses must be protected from contact

with the boil out chemicals.

3.3 SYSTEM CLEAN OUT

Many boilers have been ruined with system

contaminants such as pipe dope, cutting oil,

metal shavings or chips and other debris which

are left in the piping. If these contaminants are

not removed, they will end up in the boiler.

During this system clean out, the boiler make-up

water must be properly softened and treated. At

the conclusion of the system clean out, the

condensate must be reconnected.

For old or existing steam systems, the installation

process may have jarred debris loose. Following

the boil out of the new boiler, the condensate

should be wasted until it is within proper

guidelines. Check all steam trap strainers to

assure their cleanliness. Refer to the succeeding

section on replacement boiler installations.

SYSTEM CLEANING PROCEDURE

For steam systems, the boiler will need to be

connected to the header utilizing steam to purge

the piping and thus push the debris out of the

system. However, at this time all condensate

must be wasted until it runs clear and water

analysis of the condensate indicates that it is free

of contaminants. Steam trap strainers must be

periodically opened and cleaned of any debris

which accumulates.

3.4 REPLACEMENT BOILER INSTALLATIONS:

PROTECTION AGAINST CORROSION & SEDIMENT

BOILER MUST CONTROL FEED WATER

The water feed to the boiler must be controlled by

the boiler-mounted water level control. It is

unacceptable to use gravity return or to let the

water feed be controlled by a condensate/

receiver/ condensate pump system. The water

feed to the boiler must be controlled:

the entire system. A chemical treatment company

should be consulted for the proper means of this

chemical cleaning.

Replace any piping considered to be deteriorated

beyond safe or cleanable condition. Flush the

system clean, being certain to isolate the boiler.

by a feed pump control which is mounted on

the boiler. This control is to activate the feed

pump on a boiler feed system. It will be

necessary to supply such a system if not already

installed. - OR -

by an automatic water feeder mounted on the

boiler. This is used only on systems requiring

100% make-up, such as humidification, steam

process, etc.

DO NOT FLUSH THE SYSTEM THROUGH THE

BOILER

NOTE: For some old systems, there is a

reluctance to clean the piping because of the

possibility of leaks occurring in badly corroded

lines. Should the customer refuse cleaning, it is

necessary to install filtration equipment. Install

either a fibrous filter or a centrifugal filter in the

boiler return piping. This will collect and remove

sediment from the system. A booster pump may

have to be installed as well to overcome the

additional pressure drop introduced in the line by

the filter. When filling the system, provide

chemical treatment as outlined in Section 3.5.

NOTE

It is not recommended to provide the make-up for

a closed steam heating system to the boiler by

means of a water feeder. It is preferred that

system make-up be connected to the condensate

return tank of a boiler feed system.

A boiler feed system may be used in conjunction

with an existing condensate receiver system by

allowing the receiver system to pump condensate

into the boiler feed system tank.

CAUTION

Failure to properly clean the system or to install

mechanical sediment removal equipment can

result in tube blockage and severe corrosion plus

damage to pumps, controls, and air removal

device.

CLEAN OR REPLACE ALL SYSTEM PIPING

AND HEATING UNITS

Arrange for chemical and mechanical cleaning of

3.5 BOILER WATER TREATMENT

PURPOSE OF WATER TREATMENT

WATER SOFTENER

Water treatment is required for satisfactory

operation of the boiler. It must be devised to

prevent depositing of scale and to prevent

corrosion from acids, oxygen and other such

harmful elements that may be in the water supply.

A qualified water treatment chemist should be

consulted and the water systematically treated.

It is highly recommended that a zeolite water

softener be used for all make-up to the boiler. It is

intended that this be used in addition to the

chemical treatment of the boiler. Water softening

removes calcium and magnesium, the primary

causes of hard boiler scale.

CONTINUOUS MONITORING REQUIRED

Water treatment should be checked and

maintained whenever the boiler is operating. The

boiler operator should be sure that the boiler is

not operating for long periods without proper

water treatment. Water treatment may vary from

season to season or over a period of time.

Therefore, the water treatment procedure should

be checked not less than four times a year, and

possibly more frequently as the local water

conditions may indicate.

OBJECTIVES

The basic objectives of water treatment are:

1. Prevent the accumulation of scale and

deposits in the boiler.

2. Remove dissolved gases from the

water.

3. Protect the boiler against corrosion.

4. Maintain the highest possible boiler

fuel efficiency.

5. Decrease the amount of boiler down

time from cleaning.

3.6 EXTERNAL "FIRE-SIDE" CLEANING

PURPOSE

If the buildup of soot is appreciable, the flue gas

venting system must be thoroughly inspected

internally as well, and cleaned as necessary.

Carbon (soot) is an insulator and is corrosive.

The heating surface of a boiler must be kept free

from soot accumulation to keep the boiler

operating at its highest efficiency and to avoid

damage from corrosion.

IMPORTANT

If either soot or condensation is apparent, a boiler

service technician should be consulted. The

presence of soot indicates poor combustion and

possibly hazardous boiler operation. Failure to do

so may result in fire, explosion potential, or

asphyxiation. A combustion test and burner

adjustments should be undertaken at once.

SOOT REMOVAL

If the yearly inspection of the boiler tube surfaces

reveals a build-up of either soot or rust (usually

due to condensation), the tubes should be

thoroughly brushed. (Tube cleaning brushes are

available from Bryan Steam) To inspect and, if

necessary, clean the tube surfaces and flue

collector, first remove the tube access panels.

Examine the exterior of the tubes for evidence of

soot or rust. Using a flashlight, carefully look

between the tubes. There should be an

unobstructed opening between all tubes, and the

top surfaces of the tube must be free from soot

accumulation. Also inspect the interior of the flue

collector. Brush or vacuum the soot from all

surfaces. Be sure to cover atmospheric burners

with a protective cover during cleaning to prevent

soot from falling into them.

Rust on the tubes indicates that boiler-operating

temperatures are too low. The set point of the

boiler operating control must be no less than

130 F for natural gas or propane firing, and

170 F for oil fired boilers. Boilers equipped with

outdoor reset control must also follow these

limits.

3.7 SUGGESTED MAINTENANCE SCHEDULE

DAILY

MONTHLY

1. Make visual inspection of gauges, monitors, and

indicators and record readings in boiler log.

1. Make visual inspection of linkage and proper

operation of flue, vent, stack, or outlet dampers. Check

draft as specified in Section 2 of this manual.

2. Make visual check of instrument and equipment

settings against factory recommended specifications.

2. Check float low water cutoff as described above.

3. Check operation of float type low water cutoffs to

ensure control is functioning. The lower piping

connections of float type level controls should have a

suitable blowdown valve piped into a proper drain. This

valve should be opened periodically to allow any sludge

accumulated in the control to be flushed out. On closed

loop water heating systems this should not be often

required. Consult manufacturer's instructions.

3. For those units equipped with a power burner, check

low draft, fan, air pressure and damper position

interlocks as specified in burner manual.

4. Check high and low gas pressure interlocks. Refer to

manufacturers instructions for correct procedure.

5. Check high and low oil pressure interlocks. Refer to

manufacturers instructions for correct procedure.

WEEKLY

1. On units equipped with firing rate control, verify that it

is functioning correctly by adjusting control and

observing if input changes accordingly.

ANNUALLY

1. Perform leakage tests on pilot and main gas or main

oil fuel valves as specified in manufacturers instructions.

2. Make visual inspection of igniter and pilot flame. For

an atmospheric unit, confirm pilot flame is as shown in

this manual (Section 1.9) and that the main burners light

off correctly (smoothly) and that the flame is clean and

normal. For units with a power burner, check pilot flame

signal strength as specified in burner manual.

2. Check operating control, high limit, low fire start

control, and low water cutoff as specified in

manufacturers instructions.

3. For units equipped with power burners, check air

atomizing interlock, fuel valve interlock switch, purge

switch, burner position interlock, and fuel changeover

control, as specified in burner manual.

3. Check pilot and main fuel valves for correct operation.

Open limit switch - make audible and visual check -

check valve position indicators and check fuel meters, if

supplied.

4. The boiler should be checked at least yearly by the

local gas utility company. Particular attention should be

paid to the pilot burner safety devices. The pilot burner

should be checked to ensure that prompt ignition of all

burners occurs as the gas valve opens. Refer to Section

1.9.

4. Confirm boiler area is free of combustible materials

and that there is nothing obstructing air openings, draft

hood relief openings, etc.

5. Check combustion safety controls for flame failure

and flame signal strength as specified in manufacturer's

instructions located at the back of this manual for

atmospheric units or in the burner manual for units

equipped with a power burner.

5. The flue gas passages and the exterior surfaces of

the boiler tubes should be inspected at least annually.

Any accumulation of soot or debris should be thoroughly

cleaned out.

6. If the yearly inspection of the boiler tube surfaces

reveals a build-up of soot (carbon) or rust, the tubes

surfaces should be thoroughly brushed. Failure to do so

may result in fire or asphyxiation hazards.

6. Check all limit controls as specified in manufacturer's

manual.

7. Check float low water cutoff as described above.

7. The boiler pressure vessel and piping should be

checked annually.

8. Check combustion safety control for pilot turndown

and refractory hold-in as specified in manufacturer's

instructions.

3.8 FLOAT-ACTUATED WATER LEVEL CONTROLS

Inspect float type water level controls for proper

operation. Visually inspect sight glasses for

evidence of scale forming residues. Refer to

section 3.9 for gauge glass maintenance.

On humidification or process systems, the

blowdown schedule should be based on

recommendation from a water treatment and

maintenance program specifically designed for

the boiler.

On closed steam heating systems, the float low

water cutoff should be blown down by means of

At the annual inspection, all float type level

controls should be disassembled, cleaned and

inspected thoroughly. When re-installed these

controls must be given an operational test.

opening

blowdown valve on the lower

connection of the cutoff once per day.

3.9 WATER GAUGE GLASSES

INSTALLATION

INSPECTION

Check with the maintenance supervisor and

engineering for the proper glass to be used.

Compare the box and the glass label or marking

to ascertain that the gauge glass ratings or

temperature and pressure are suitable for use on

the boiler. Use new gaskets when replacing

glass. The gaskets used should be the same type

as those originally supplied with the boiler. Make

certain that the gauge glass valves are properly

aligned.

To examine for scratches, shine a bright

concentrated light at about a 45 angle. Anything

that glistens brightly should be inspected closely.

Any scratch which glistens and will catch a

fingernail, or crescent-shaped or star-shaped

mark is cause for replacement. This is because

scratches, corrosion, chips and surface damage

weaken the glass. If inner surface appears cloudy

or roughened, and will not respond to cleaning

procedures, this is evidence of chemical attack. If

severe, this is cause for replacement.

All bolts and nuts must be free running and well

lubricated, preferably with

graphite type

REPLACEMENT OF GLASS

lubricant. Washers under nuts and bolt heads are

desirable. DO NOT tighten while equipment is in

operation.

Any glass that has been removed from its

mounting in process boilers, regardless of the

reason for removal, should be discarded and

replaced with a new glass and gaskets. Used

glasses may contain hidden damage and

represent a safety hazard.

MAINTENANCE

Inspect the gauge glass regularly for any signs of

clouding or scratching. In new processes, the

gauge glass should be inspected daily until the

need for replacement becomes apparent. This

will help establish the routine inspection cycle.

Be sure that the replacement glass is suitable for

service conditions.

Protective shields to keep cold air, water, or

falling objects from glass must be replaced.

The gauge glass should be blown down daily so

as to remove accumulated sediment from the

valves.

4.0 IDLE BOILER CARE AND LAY-UP

GENERAL

(when used) should be kept to a minimum so the

reduction of solids is achieved by the increased

manual blowdown.

Corrosion damage to boilers is often the result of

improper lay-up during non-operating periods.

Substantial damage can occur in only a few days

in proper precautions are not taken. This damage

is irreversible and will reduce boiler reliability,

increase maintenance costs and eventually

shorten the useful life of the boiler tubes.

WASHDOWN

As the boiler cannot be washed immediately, the

heat in the boiler may cause baking of residual

sludge. The boiler should not be drained until

cooled enough to prevent this. However, never

leave the boiler filled with water for any extended

period of time without taking measures to prevent

corrosion.

Idle boilers are vulnerable to attack when air

contacts untreated wet metal surfaces. To prevent

corrosion, the boiler metal must be protected by

either keeping the surfaces completely dry or

excluding air from the boiler. Air exclusion is

accomplished either by keeping the boiler

completely full of water (short term lay-up) or filling

the boiler with nitrogen gas (long-term lay-up).

The nitrogen gas prevents air infiltration and does

not react with the metal.

LAY-UP CONSIDERATIONS

There are two basic methods of steam boiler lay-

up: Wet lay up or Dry lay-up. The choice of which

method should be used depends on:

The possibility that the boiler may need to be

placed in operation on short notice.

Disposal of lay-up solutions

In addition to the corrosion damage that occurs,

the metal particles that are released will form an

insulating scale on the tubes when the boiler is

returned to service. These corrosion products will

accumulate on critical heat transfer areas of the

boiler, increasing the potential for localized

corrosion and over heating.

Freezing potential

Wet Lay-up is recommended for relatively short

outages, such as seasonal lay-up. This method

has the advantage of allowing the boiler to be

brought on line with short notice. But it can pose

problems if there is any likelihood of freezing.

PRE-OPERATIONAL CLEANING AND LAY-UP

Proper lay-up techniques must be used on an idle

boiler even if it has never been in operation.

Before pre-operational lay-up, the boiler must be

chemically cleaned as outlined in Section 3.2 of

this manual. This is required, as noted in this

section, to remove preservatives, oil and grease

from the tube surfaces. Follow the short term or

long term lay-up procedure as appropriate.

Dry Lay-up is recommended for longer periods of

boiler shut-down or storage. But it is practical only

if boiler can be drained hot (120 F to 170 F) or if

external drying can be provided.

WET LAY-UP OF STEAM BOILERS - SHORT

TERM

In the wet lay-up procedure, the boiler is to be

filled with chemically treated water and sealed to

prevent air in-leakage. Nitrogen gas under slight

pressure can also be used to displace air and

protect the boiler surfaces from corrosion. The

following steps should be taken for wet lay-up of a

boiler:

TAKING BOILERS OFF LINE

In operation, boiler water contains suspended

solids which are held in suspension due to water

circulation and the action of treatment chemicals.

Unless care is exercised when draining the boiler,

these suspended solids settle on the tube

surfaces and will air dry to an adherent deposit,

sometimes requiring chemical cleaning to remove.

In addition, these deposits may be misleading

regarding the effectiveness of the chemical

treatment program.

1a. Procedure for operational boiler:

At least thirty minutes before the boiler comes off

line, add the following chemicals:

Sodium Sulfite - 0.5 lbs. per 100 gallons water

Polymeric Sludge Dispersant - 0.1 lbs. per 100

gallons water

Caustic Soda - 0.3 lbs. per 100 gallons water

PRE-SHUTDOWN PRECAUTIONS

For a period of three to seven days prior to

shutdown, manual blowdown frequency should be

increased. During this period, the lower

conductivity limit should be below 3500 micro-

mohs per centimeter. The feed of internal

treatment must be increased to maintain a specific

residual concentration. Continuous blowdown

1b. Procedure for idle boiler:

If the boiler has never been on line or has been

out of service for cleaning - Select the highest

quality water available to fill the boiler. Steam

condensate, softened water, filtered fresh water,

and boiler feedwater are generally acceptable for

lay-up. Raw city water is not recommended and

should not be used.

chemical. Then repeat Step. 2. Pay attention to

the maintenance of the valves being used to

isolate the boiler to prevent leakage and resultant

dilution of the lay-up solution.

Prepare the chemical solution described in (1a) in

a separate tank. Adhere to the safety precautions

described in Section 3.2 of this manual. Add the

concentrated lay-up solution to the boiler during

the time it is being filled.

ALTERNATE METHOD

An alternate wet lay-up method is to pipe clean

continuous blowdown water from a properly

treated boiler into any convenient bottom

connection on the idle boiler, allowing the water to

flow through the boiler and out the top (through

any convenient top opening) to the sewer. This

method will insure a continuous, complete fill with

warm, properly treated water. It also prevents in-

leakage of air by keeping the boiler slightly

pressurized. It may also provide enough heat to

keep the fireside of the boiler dry and possibly

produce adequate freeze protection.

After the boiler is filled and the lay-up solution has

been added, the boiler is to be operated for thirty

minutes at low fire to circulate and mix the

chemicals.

2. After filling, the boiler must be closed or

blanked tightly. The power supply to the boiler

must be cut off. Vent all air from the top of the

boiler to allow complete fill with the required

solution. Nitrogen gas at 5 psig may be introduced

though a suitable opening to prevent air in-

leakage during the lay-up period. An alternative to

the nitrogen gas (see safety precautions under dry

lay-up) is to install a 55 gallon drum or auxiliary

vessel as shown in Figure 3.11A. This is to be

fitted with a cover and filled with properly treated

water. This vessel or drum should be connected

to an available opening in the top of the vessel. Its

purpose is to create a hydrostatic head and to

allow a ready visual check of water level loss or

in-leakage during the lay-up period.

DRY LAY-UP OF STEAM BOILERS - LONG

TERM

The dry lay-up method recommended requires

that the boiler be drained, dried as completely as

is possible, all opening and valves closed.

Nitrogen gas at 5 psig is introduced to the boiler to

pressurize it and prevent air in-leakage. The

success of the procedure depends on the

thorough drying of the boiler metal surfaces after

draining and the exclusion of air during the lay-up.

CAUTION

The use of nitrogen for blanketing is

recommended in both the wet and dry lay-up

procedures. Even though nitrogen in dilute

quantities is non-toxic, it will not support life.

Precautions must be taken before entering

equipment filled with nitrogen for inspections or

any other purposes. These precautions shall be

as follows:

disconnection of nitrogen supply line

complete purging and venting of the equipment

with fresh air

testing oxygen levels inside before any attempt

to enter

Figure 3.11A: WET LAY-UP STATIC HEAD

DRUM

all confined entry guidelines applicable to site

must be followed

3. During lay-up, test the boiler weekly to assure

the proper levels of sulfite and alkalinity. To do

this, take a sample of the boiler water from the

surface blowdown line or other high point. The

test results should be:

Sodium Sulfite 200 ppm minimum

Phenolphthalein Alkalinity (as CaCO₃)

400 ppm minimum

Appropriate caution signs shall be posted around

the equipment to alert personal that nitrogen

blanketing is in use. A boiler laid up dry must be

tagged with information that the unit is not to be

operated until the boiler is properly refilled.

If the tests indicate chemical concentration has

decreased, chemical may be introduced to the

boiler by putting it in the drum shown in Fig.

3.11A. Then lower the boiler water level to

introduced it into the boiler. Then operate the

boiler at low fire to circulate the water and mix the

1. Drain the boiler before the steam pressure falls

to zero. Then pressurize with 5 psig nitrogen gas

through a suitable top opening during draining.

The nitrogen pressure is to be maintained through

draining and subsequent storage.

An alternate method is to completely dry a clean

boil (by blowing hot dry air though the boiler) and

then purge the air from the boiler and pressurize

with 5 psig nitrogen. Be aware that all metal

surfaces which are not completely dry are

vulnerable to corrosion, particularly if oxygen is

present.

1. If the boiler was pressurized with nitrogen,

disconnect the nitrogen supply source and vent

the boiler.

2. Using the blowdown valve, drain the boiler

partially and make up with feedwater so as to

dilute the chemical residuals to operating

concentration levels.

2. If a boiler has been down for repairs and is to

be laid up, it should be operated to pressurize with

steam and then drained and pressurized with

nitrogen as in step 1.

3. After the boiler water concentrations and the

water level are returned to proper operating

conditions, the boiler can be started in the normal

manner.

3. All connections must be blanked or tightly

closed.

After Dry Lay-Up

To start an idle boiler after dry lay-up, use the

following procedure:

Note: Operating boilers must be removed from

service to minimize adherence of boiler water

suspended solids on boiler metal surfaces. Refer

to previous instructions for boiler washdown.

1. Disconnect the nitrogen supply source and vent

the boiler in a safe manner - external to the

building and away from air intakes. Then

thoroughly purge the boiler of nitrogen with dry air.

RETURNING IDLE BOILER TO SERVICE

After wet lay-up

To start an idle boiler after wet lay-up, use the

following procedure:

2. The boiler was to have been cleaned before the

lay up procedure. So it is necessary only to fill the

boiler with properly treated water. Then proceed

with start-up.

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