CleaverBrooks FLX Series Guide

Manual Part No. 750-364
MODEL FLX
PACKAGED BOILER
12,500,000 to 25,000,000 BTU/hr
Hot Water
Fuel: Light Oil, Gas or Combination
09/2013

MODEL FLX
PACKAGED BOILER
Operation, Service, and Parts Manual
12,500,000 to 25,000,000 Btu/hr
Fuel: Light Oil, Gas or Combination
Please direct purchase orders for replacement manuals to your local Cleaver-Brooks authorized representative
Manual Part No. 750-364
Revised 9/2013 Printed in U.S.A.
Cleaver-Brooks 2013

i
TO: Owners, Operators and/or Maintenance Personnel
This operating manual presents information that will help to properly operate and care for the equipment. Study its contents
carefully. The unit will provide good service and continued operation if proper operating and maintenance instructions are fol-
lowed. No attempt should be made to operate the unit until the principles of operation and all of the components are thoroughly
understood. Failure to follow all applicable instructions and warnings may result in severe personal injury or death.
It is the responsibility of the owner to train and advise not only his or her personnel, but the contractors' personnel who are ser-
vicing, repairing or operating the equipment, in all safety aspects.
Cleaver-Brooks equipment is designed and engineered to give long life and excellent service on the job. The electrical and
mechanical devices supplied as part of the unit were chosen because of their known ability to perform; however, proper oper-
ating techniques and maintenance procedures must be followed at all times. Although these components afford a high degree
of protection and safety, operation of equipment is not to be considered free from all dangers and hazards inherent in handling
and firing of fuel.
Any "automatic" features included in the design do not relieve the attendant of any responsibility. Such features merely free
him of certain repetitive chores and give him more time to devote to the proper upkeep of equipment.
It is solely the operator’s responsibility to properly operate and maintain the equipment. No amount of written instructions can
replace intelligent thinking and reasoning and this manual is not intended to relieve the operating personnel of the responsibility
for proper operation. On the other hand, a thorough understanding of this manual is required before attempting to operate, main-
tain, service, or repair this equipment.
Because of state, local, or other applicable codes, there are a variety of electric controls and safety devices which vary consid-
erably from one boiler to another. This manual contains information designed to show how a basic burner operates.
Operating controls will normally function for long periods of time and we have found that some operators become lax in their
daily or monthly testing, assuming that normal operation will continue indefinitely. Malfunctions of controls lead to uneco-
nomical operation and damage and, in most cases, these conditions can be traced directly to carelessness and deficiencies in
testing and maintenance.
It is recommended that a boiler room log or record be maintained. Recording of daily, weekly, monthly and yearly maintenance
activities and recording of any unusual operation will serve as a valuable guide to any necessary investigation.
Most instances of major boiler damage are the result of operation with low water. We cannot emphasize too strongly the need
for the operator to periodically check his low water controls and to follow good maintenance and testing practices. Cross-con-
necting piping to low water devices must be internally inspected periodically to guard against any stoppages which could ob-
struct the free flow of water to the low water devices. Float bowls of these controls must be inspected frequently to check for
the presence of foreign substances that would impede float ball movement.
The waterside condition of the pressure vessel is of extreme importance. Waterside surfaces should be inspected frequently to
check for the presence of any mud, sludge, scale or corrosion.
The services of a qualified water treating company or a water consultant to recommend the proper boiler water treating practices
are essential.
The operation of this equipment by the owner and his or her operating personnel must comply with all requirements or regula-
tions of his insurance company and/or other authority having jurisdiction. In the event of any conflict or inconsistency between
such requirements and the warnings or instructions contained herein, please contact Cleaver-Brooks before proceeding.
DO NOT OPERATE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS YOU FULLY UNDERSTAND ALL
APPLICABLE SECTIONS OF THIS MANUAL.
DO NOT ALLOW OTHERS TO OPERATE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS THEY FULLY
UNDERSTAND ALL APPLICABLE SECTIONS OF THIS MANUAL.
FAILURE TO FOLLOW ALL APPLICABLE WARNINGS AND INSTRUCTIONS MAY RESULT IN SEVERE
PERSONAL INJURY OR DEATH.
!DANGER WARNING

TABLE OF CONTENTS
Chapter 1
General Description
A. General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
B. The Boiler. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
C. Construction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
E. Hot Water Controls (All Fuels) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Chapter 2
ProFire™ EV / LNEV Burner
A. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
B. Combustion Air Handling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
C. Firing Head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
D. Oil System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
E. Gas System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
F. Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
G. FGR System - Low NOx Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
H. Burner Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Chapter 3
Pressure Vessel Care
A. General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
B. Water Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
C. Water Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
D. Using Glycol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
E. Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
F. Boilout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
G. Washing Out. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
H. Periodic Inspections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
I. Preparation for Extended Layup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Chapter 4
Sequence Of Operation
A. General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
B. Circuit And Interlock Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
C. Sequence Of Operation - Oil Or Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
D. Flame Loss Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
ii

Chapter 5
Adjustment Procedures
A. Burner Operating Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
B. Operating Limit Temperature Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
C. High Limit Temperature Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
D. Low Water Cutoff Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
E.Combustion Air Proving Switch (CAPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
F. Gas Pilot Flame Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
G. Gas Pressure And Flow Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
H.Gas Fuel Combustion Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
I. Low Gas Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
J.High Gas Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
K.Fuel Oil Pressure And Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
L.Fuel Oil Combustion Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
M. Low Oil Pressure Switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Chapter 6
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Chapter 7
Inspection And Maintenance
A. General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
B. Periodic Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
C. Fireside Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
D. Upper Pass Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
E. Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
F. Oil Burner Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
G. Gas Burner Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
H. Refractory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
I. Casing Seals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
Chapter 8
Parts
Recommended Spare Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2
Outer Casing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
Inner Casing,. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
Temperature Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7
Level Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8
EV Burner. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9
iii

iv

750-364 1-1
CHAPTER 1
GENERAL DESCRIPTION
A. General
This manual applies to Cleaver-Brooks FLX Model boilers
(hot water) in sizes ranging from 12,500,000 to 25,000,000
Btu/hr input.
Fuel Series
700- Gas
100-No.2 0il
200 - Combination Gas & No.2 Oil
Design Pressure
30, 60, 125, or 160 psig hot water
!DANGER
CAUTION
The care taken in placing the boiler into initial
service is vital to continuous, reliable operation.
If the boiler is to be used for temporary heat (for
example in new construction), properly treated
water must be used. Failure to do so can be
detrimental to the boiler.
A. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
B. The Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
C. Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
D. Hot Water Controls (All Fuels). . . . . . . . . . . . . . . . 1-2

Chapter 1 GENERAL DESCRIPTION
1-2 750-364
B. The Boiler
The Cleaver-Brooks Model FLX is a five-pass steel boiler
with flexible watertubes formed and arranged so as to direct
the flow of combustion gases through the boiler. The pressure
vessel conforms to Section I or IV of the ASME code. The
pressure vessel consists of the formed tubes, the external
downcomer, and the top and bottom drums to which they
connect. The heated area of the pressure vessel is contained
within a gas tight insulated casing that is composed of
removable formed steel panels.
The boiler and related equipment installation are to be in
compliance with the standards of the National Board of Fire
Underwriters. Installation should also conform to state and
local codes governing such equipment. Prior to installation,
the proper authorities having jurisdiction are to be consulted,
permits obtained, etc. All boilers in the FLX series comply,
when equipped with optional equipment, to Industrial Risk
Insurers (IRI), Factory Mutual (FM), or other insuring
underwriters requirements.
The Model FLX boiler is a packaged watertube boiler of
welded steel construction and consists of a pressure vessel,
burner, burner controls, forced draft fan, damper, refractory,
and appropriate boiler trim.
Hot water is commonly used in heating applications with the
boiler supplying water to the system at 180 F to 220 F. The
operating pressure for the Model FLX 1250-2500 is 30 psig
to 160 psig.
Boilers are defined according to design pressure and operat-
ing pressure. Design pressure is the maximum pressure used
in the design of the boiler for the purpose of calculating the
minimum permissible thickness or physical characteristics of
the pressure vessel parts of the boiler. Typically, the safety
valves are set at or below design pressure. Operating pres-
sure is the pressure of the boiler at which it normally oper-
ates. The operating pressure usually is maintained at a
suitable level below the setting of the pressure relieving
valve(s) to prevent their frequent opening during normal
operation.
The type of service that your boiler is required to provide has
an important bearing on the amount of waterside care it will
require.
!DANGER
CAUTION
Waterside care is of prime importance. For
specific information or assistance with your
water treatment requirements, contact your
Cleaver-Brooks service and parts represen-
tative. Failure to follow these instructions
could result in equipment damage.
Feedwater equipment should be checked before use. Be sure
that all valves, piping, boiler feed pumps, and receivers are
installed in accordance with prevailing codes and practices.
Strict attention to water requirements is essential to proper
boiler operation and length of service, and will pay dividends
in the form of longer life, less down-time, and prevention of
costly repairs.
Care taken in placing the pressure vessel into initial service is
vital. The waterside of new boilers and new or remodeled
steam or hot water systems may contain oil, grease or other
foreign matter. A method of boiling out the vessel to remove
accumulations is described in Chapter 3.
The operator should be familiar with this manual in its
entirety before attempting to place the unit into operation.
C. Construction
Hot water boilers designed for 250F at 160 psig or less are
constructed in accordance with Section IV, Heating Boilers,
of ASME Code. Hot water boilers designed for operating
temperatures above 250F are constructed in accordance with
Section I of ASME Code.
D. Hot Water Controls (All Fuels)
1. Water Temperature Gauge: Indicates the boiler internal
water temperature.
2. Water Pressure Gauge: Indicates the internal pressure of
the boiler.
3. Operating Limit Temperature Control: Breaks a circuit to
stop burner operation on a rise of boiler temperature at a
selected setting. It is adjusted to stop or start the burner
at a preselected operating temperature.
4. High Limit Temperature Control: Breaks a circuit to stop
burner operation on a rise of temperature at a selected
setting. It is adjusted to stop burner at a preselected
temperature above the operating control setting. The
high limit temperature control is equipped with a manual
reset.
5. Modulating Temperature Control: Senses changing
boiler water temperature and transmits the information to
change the burner firing rate when the manual-automatic
switch is set on Automatic.
6. Low Water Cutoff: Breaks the circuit to stop burner
operation if the water level in the boiler drops below safe
operating point, activating low-water light and optional
alarm bell if burner is so equipped.

GENERAL DESCRIPTION Chapter 1
750-364 1-3
7. Auxiliary Low Water Cutoff (Optional): Breaks the
circuit to stop burner operation if the water level in the
boiler drops below the master low-water cutoff point.
8. Safety Valve(s): Prevent buildup over the design
pressure of the pressure vessel. The size, rating and
number of valves on a boiler is determined by the ASME
Boiler Code. The safety valves and the discharge piping
are to be installed to conform to the ASME code
requirements. The installation of a valve is of primary
importance to its service life. A valve must be mounted
in a vertical position so that discharge piping and code-
required drains can be properly piped to prevent buildup
of back pressure and accumulation of foreign material
around the valve seat area. Apply only a moderate
amount of pipe compound to male threads and avoid
over-tightening, which can distort the seats. Use only
flat-jawed wrenches on the flats provided. When
installing a flange-connected valve, use a new gasket and
draw the mounting bolts down evenly. Do not install or
remove side outlet valves by using a pipe or wrench in
the outlet.
!DANGER
WARNING
Only properly certified personnel such as
the relief valve manufacturer’s certified
representative can adjust or repairthe boiler
relief valves. Failure to follow these
instructions could result in serious
personal injury or death.

Chapter 1 GENERAL DESCRIPTION
1-4 750-364