CleaverBrooks CBEX-DE Installation guide

CBEX-DE
Dryback Elite Boiler
250-800 HP
Operation and Maintenance
750-392 10/2019

TO: Owners, Operators and 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 followed. 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 ensure all service, repair, and operating personnel have received proper safety training.
Proper operating techniques and maintenance procedures must be followed at all times. Although the components supplied afford a
high degree of protection and safety, due attention is required to the dangers and hazards inherent in handling and firing of fuel.
“Automatic” features, where present, should not be understood as substituting for the normal responsibilities of the attendant. Such
features merely alleviate certain repetitive chores, allowing more time for proper upkeep of the equipment.
This manual is intended for a general scope of application. Because of state, local, or other applicable codes, controls and safety de-
vices may vary considerably from those described herein.
It is recommended that a boiler room log or record be maintained. Recording of daily, weekly, monthly and yearly maintenance activ-
ities 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 the low water controls and to follow good maintenance and testing practices. Cross-connecting piping
to low water devices must be internally inspected periodically to guard against stoppages which could obstruct the free flow of water
to the low water devices. Float bowls of these controls, where applicable, 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 mud, sludge, scale and corrosion.
It is essential to obtain the services of a qualified water treating company or a water consultant to recommend the proper boiler water
treating practices for your specific application.
The operation of this equipment must comply with all requirements or regulations of the owner’s 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

CONTENTS
CHAPTER 1 Introduction 1-1
Overview 1-1
Component Locations 1-3
CHAPTER 2 Waterside Care 2-1
Water requirements - steam boilers 2-1
Water requirements - hot water boilers 2-2
Water Treatment 2-4
Cleaning 2-5
Boil-Out of a New Unit 2-6
Washing Out 2-8
Blowdown - Steam Boilers 2-9
Periodic Inspection 2-12
Preparation for Extended Layup 2-13
CHAPTER 3 Preparations for Startup 3-1
Pre-Startup Adjustments 3-1
Burner Operating Controls: General 3-2
Control Checks 3-5
Low Water Cutoff Devices: Steam and Hot Water 3-6
Combustion Air Proving Switch 3-6
Atomizing Air Proving Switch 3-6
Gas Pilot Flame Adjustment 3-7
Gas Pressure and Flow Information 3-8
Adjusting Combustion 3-12
Linkage Settings (optional single-point systems) 3-12
Low Gas Pressure Switch 3-19
High Gas Pressure Switch 3-20
Burner Drawer Adjustment 3-20
Oil Drawer Switch 3-21
CHAPTER 4 Startup and Operation 4-1
Sequence of Operation 4-1
Flame Loss Sequence 4-4
General Preparation for Startup: All Fuels 4-6
Control Settings: Steam and Hot Water 4-7
Gas Pilot 4-7
Atomizing Air 4-7
Firing Preparations for No. 2 Oil (Series 100, 200) 4-9
Firing Preparations for Gas (Series 200, 700) 4-11
Startup, Operating, and Shutdown: All Fuels 4-12
Control Operational Checks 4-14
Troubleshooting 4-15
Emergency Shutdown 4-19

CHAPTER 5 Inspection and Maintenance 5-1
Periodic Inspection 5-2
Fireside Cleaning 5-3
Water Level Controls 5-3
Water Gauge Glass 5-4
Electrical Controls 5-5
Flame Safety Control 5-5
Removing Burner Drawer 5-7
Oil Burner Maintenance 5-7
Gas Burner Maintenance 5-9
Motorized Gas Valve 5-10
Solenoid Valves 5-10
Air Control Damper 5-10
Fan/Motor Cassette Removal 5-11
IFGR Inspection and Adjustment 5-12
Fan/Motor Cassette Replacement 5-13
Safety Valves 5-14
Fuel Oil Metering Valve 5-15
Air Pump and Lubricating System 5-17
Refractory 5-21
Front and Rear Access 5-26
Lubrication 5-28
Combustion Adjustments 5-28
Linkage Systems 5-29
CHAPTER 6 Parts 6-1
Burner Assembly 30 PPM/60 PPM/Uncontrolled Emissions 6-2
Arch Brick and Liner Tile 6-5
Front Head 6-6
Blower Cassette 6-8
Modbus Actuators (parallel positioning) 6-9
Gas Train 6-12
Light Oil Components 6-13
Low Water Cutoff 6-15
Auxiliary Low Water Cutoff 6-16
Pressure Controls, Steam 6-17
Temperature Controls, Hot Water 6-18
Rear Head 6-19

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CHAPTER 1 Introduction
1.1 — Overview
The CBEX-DE boiler is a packaged firetube boiler of welded steel construction and consists of a pressure vessel,
burner, burner controls, forced draft fan, air compressor for oil atomization, oil pump, refractory, and boiler trim
supplied according to customer’s request.
Like all CBEX boilers, the CBEX-DE features spiral tubes for enhanced heat transfer. Other features include:
•30 ppm NOx standard
•Hinged or davited insulated rear door with sight port
FIGURE 1-1. CBEX-DE cutaway view

Introduction
1-2 750-392
CBEX -DE
The CBEX-DE is a 2-pass dry-back design. The flame originates in the furnace. As the combustion gases travel
down the furnace and through the firetubes, heat from the flame and combustion gases is transferred to the
water to generate steam.
For lower emissions the CBEX-DE firetube boiler line is designed to incorporate induced Flue Gas Recirculation
(FGR). FGR may be used when firing either natural gas and/or light oil.
The FGR system mixes a portion of the relatively cool flue gas from the exit of the second-pass tubes with the
incoming combustion air to reduce the furnace flame temperature, thereby reducing NOx emissions. In this
approach, the combustion air fan handles both the combustion air and the recirculated flue gases. Carbon mon-
oxide (CO) emissions also tend to be lower due to increased turbulence caused by the addition of the flue gases
into the combustion air stream.
The low emission design can affect the selection of the combustion air fan, motor, burner, and other components.
Several different system configurations are available, depending on the requirements for NOx emissions and the
fuels used. All systems use similar primary components, but fan and motor sizes as well as the FGR damper may
differ.
Installation should conform to state and local codes. Prior to installation, the proper authorities having jurisdic-
tion are to be consulted, permits obtained, etc.
CBEX-DE boilers offer compliance with multiple insurers’ requirements. Equipment provided may vary depending
on insurance.
Steam boilers are built for a specific design pressure, which is the pressure used in calculating the minimum per-
missible thickness or physical characteristics of the pressure vessel components. Typically, the safety valves are
set at or below design pressure.
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. Waterside care will con-
tinue to be important throughout the lifetime of the boiler. A boilout method for new boilers, as well as general
waterside care information, can be found in Chapter 2.
1.1.1 — Construction
Steam boilers designed for 15 psig and hot water boilers designed for 250º F at 125 psi or less are constructed
in accordance with Section IV, Heating Boilers, of ASME Code.
Steam boilers designed for operating pressures exceeding 15 psig are constructed in accordance with Section I,
Power Boilers, of the ASME Code. Hot water boilers designed for operating temperatures above 250º F or 125
psi are likewise built to Section I of the ASME Code.

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Component Locations
1.2 — Component Locations
FIGURE 1-2. Boiler front view (67” boiler - configurations may vary)
1. Blower assembly
2. Feedwater piping
3. Main gas train
4. Burner drawer
5. Oil system
6. Aux low water cutoff
1
2
3
4
5
6
FIGURE 1-3. Boiler side view (67” boiler - configurations may vary)
1
7
8
9
10
11
12
13
7. Control panel/entrance panel
8. Low water cutoff
9. Pressure controls
10. Safety valves
11. Oil supply piping
12. Air compressor
13. Bottom blowdown piping

Introduction
1-4 750-392
CBEX -DE
1.2.1 — Blower assembly
The blower assembly, also called the cassette,
comprises the fan and motor and can be removed
as a unit from the front of the boiler without open-
ing the front door. The front davit arm is used to
support the blower cassette during removal.
1.2.2 — Feedwater piping
Feedwater piping configurations can vary. A typical configuration is shown below, comprising three-valve bypass
piping with strainer and a modulating feedwater valve.
FIGURE 1-4. Fan/motor cassette
FIGURE 1-5. Feedwater piping

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Component Locations
1.2.3 — Main gas train
Depending upon the requirements of the insurance carrier or other governing agencies, the gas train may consist
of some or all of the following items.
1. Shutoff Cocks: For manually opening and closing the main fuel gas supply downstream of the main gas line
pressure regulator. A second shutoff cock, downstream of the main gas valve(s), is installed to provide a
means of shutting off the gas line whenever a test is made for leakage across the main gas valve.
2. Main Gas Valve: Double body safety shutoff valve. Electrically actuated valves open simultaneously to admit
gas to the burner. The downstream valve is equipped with a with a regulating actuator and a proof of closure
switch that is connected to the pre-ignition interlock circuit.
3. Main Gas Vent Valve (if required): A normally open solenoid valve installed between the two main gas valves
to vent gas to the atmosphere, should any be present in the main gas line when the gas valves are deener-
gized. The vent valve closes when the gas valves are energized.
4. Low Gas Pressure Switch: A pressure-actuated switch; closed whenever main gas line pressure is above a pre-
selected pressure. Should the pressure drop below the setting, the switch contacts open a circuit causing the
main gas valve(s) to close, or prevent the burner from starting. The switch is usually equipped with a device
that must be manually reset after being tripped.
5. High Gas Pressure Switch: A pressure actuated switch; closed whenever main gas line pressure is below a
preselected pressure. Should the pressure rise above the setting, the switch contacts will open a circuit caus-
ing the main gas valve(s) to close, or prevent the burner from starting. The switch is usually equipped with a
device that must be manually reset after being tripped.
6. Test Cocks: The body of the gas valve has 1/4-inch NPT fittings for pressure test connection.
7. Butterfly Gas Valve (not shown): The pivoted disc in the valve is directly driven by a servo motor actuator to
regulate the rate of gas flow to the burner. In optional 700-800 HP single point systems, the valve is driven by
the modulating motor through connecting linkage.
FIGURE 1-6. Main gas train
1
1
2
45
6

Introduction
1-6 750-392
CBEX -DE
1.2.4 — Pilot train
1. Gas Pilot Valve: A solenoid valve that opens during the ignition period to admit fuel to the pilot. It closes after
main flame is established. The sequence of energizing and de-energizing is controlled by the programming
relay. A second gas pilot valve may be required by insurance regulations.
2. Gas Pilot Shutoff Cock: For manually opening or closing the gas supply to gas pilot valve.
3. Gas Pressure Gauge: Indicates gas pressure to pilot.
4. Gas Pressure Regulator: Reduces incoming gas pressure to suit the pilot.
1.2.5 — Burner drawer
The burner is a nozzle-mixing orifice design with interrupted gas pilot. Burners equipped for oil use a low pres-
sure, air-atomized oil system.
FIGURE 1-7. Pilot train
1
2
3
4
FIGURE 1-8. Burner drawer
GAS HOUSING
BURNER SUPPORT
BURNER DRAWER

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1-7
Component Locations
Combination gas/oil burners include equipment for each fuel, with a fuel selector switch mounted in the control
panel. Regardless of which fuel is used, the burner operates with full modulation within its rated operating range.
The burner returns to minimum firing position for ignition.
The flame safeguard includes a flame detector to supervise both oil and gas flames, and to shut the burner down
in the event of loss of flame. The burner sequence provides a pre-purging period, proving of the pilot and main
flame, and a period of continued blower operation after shutoff to postpurge the boiler of all unburned fuel vapor.
Other safety controls shut down the burner under low-water conditions, excess steam pressure, or water tem-
perature.
Safety interlock controls include combustion and atomizing air proving switches and, depending upon the fuel
and insurance carrier requirements, controls that prove the presence of adequate fuel pressure.
The sequence of burner operation from startup through shutdown is governed by the program relay in conjunc-
tion with the operating, limit and interlock devices. The devices are wired into the circuitry to provide safe opera-
tion and protect against incorrect operating techniques.
All CBEX-DE boilers have the burner assembly integral with the front head. The burner drawer can be removed as
a unit, or the entire head may be swung open for inspection and maintenance.
Combustion air is provided by a centrifugal blower located in the front head.
Filtered primary air for atomizing fuel oil is furnished independently of combustion air by an air compressor. The
burner control circuit operates on 115 volt, single phase 60 Hz (or 50 Hz when equipped) alternating current.
The forced draft fan motor is generally operated on 3-phase service at the available main power supply voltage.
In addition to the standard basic controls supplied, other devices may be required to meet specific requirements
of an insurance carrier or local code.
Refer to the wiring diagram prepared by Cleaver-Brooks for your installation to determine the specific controls in
the burner and limit control circuits.

Introduction
1-8 750-392
CBEX -DE
1.2.6 — Oil system
The following items are applicable to all oil fired or gas and oil fired boilers.
1. Oil Shutoff Valve: Opens when energized through contacts in the programmer and allows fuel oil flow from the
oil metering valve to the burner nozzle. A light oil fired burner uses two valves operating simultaneously.
2. Fuel Oil Controller: An assembly combining into a single unit the gauges, regulators and valves required for
regulating the flow of fuel oil. All controllers have the following integral parts.
A - Oil Metering Valve: Valve metering stem moves to increase or decrease the orifice area to regulate the supply of fuel
oil to the burner nozzle in accordance with boiler load variances. Stem movement is controlled by the oil actuator or in
linkage systems by an oil metering cam.
B - Actuator: Positions the oil metering valve stem.
C - Oil Burner Pressure Gauge: Indicates pressure of the fuel oil at the metering valve.
D - Oil Pressure Regulator: For adjustment of the pressure of oil at the metering valve.
3. Oil Relief Valve: Maintains a constant oil supply pressure to the fuel
oil controller by bypassing excess fuel oil.
4. Terminal Block: Provides the connection for fuel oil input and return
to storage tank.
5. Fuel Oil Strainer: Prevents foreign matter from entering the burner
system.
6. Pressure Gauge for oil supply pressure
7. Fuel Oil Pump (not shown): Transfers fuel oil from the storage tank
and delivers it under pressure to the burner system.
FIGURE 1-9. Front head oil piping
1
1
2A
2B
2C
2D
FIGURE 1-10. Oil terminal block
3
4
5
6

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Component Locations
1.2.7 — Actuators
Individual actuators for fuel, air, and FGR are part of the
standard parallel positioning combustion control system,
and are positioned via Modbus signal from the Hawk con-
trol system.
Actuators are connected in series with the air damper actu-
ator last in the sequence. Actuators may use quick discon-
nect cables or may be hard wired depending on the
installation.
For actuator setup and configuration information as well as
combustion setup procedures, see the appropriate Hawk
controls manual.
A single-point positioning linkage system is available for
700/800 HP boilers.
1.2.8 — Control Panel
A common enclosure houses both the control panel and the electrical entrance
panel. The upper and lower sections are divided by a partition with a separate
hinged door for each section.
The upper section (low voltage) houses the boiler control system, including the PLC
and associated modules, the flame safeguard, the Hawk HMI touch screen, and the
LevelMaster panel.
External switches and indicator lights can vary according to options selected. A typ-
ical configuration will include switches for:
•FSG reset
•ALWCO reset
•Burner switch
•Fuel selector switch
The standard control system is the Cleaver-Brooks Hawk 1000, which includes a
4” touch screen.
The optional Hawk 4000 features a 7” touch screen, with a 10” screen optional.
The principal components of the HAWK 1000 are the Programmable Logic Control-
ler (PLC), touch screen Human Machine Interface (HMI), and the Flame Safety
Control. The system also includes 24VDC power supplies and various relays and circuit breakers.
FUEL 1 (GAS BUTTERFLY VALVE)
FUEL 2
(FUEL OIL
CONTROLLER)
FLUE GAS
RECIRCULATION
COMBUSTION AIR
FIGURE 1-11. Actuators
FIGURE 1-12. Control/
entrance panel

Introduction
1-10 750-392
CBEX -DE
1. Base Unit
1a. L24ER Programmable Logic Controller (PLC)
1b. Embedded I/O
2. SM2 Modbus Communications Module
3. Digital Inputs
4. Digital Outputs
5. Analog Inputs (optional)
6. Burner Control
7. Power supplies
8. Circuit breakers, relays, fuses,
etc.
9. ALWCO control
FIGURE 1-13. Hawk 1000 components, typical
The Base Unit consists of the Processor (CPU) which holds the program logic and configuration for the boiler
controller and embedded I/O modules which consist of discrete inputs, discrete outputs, and analog inputs. The
program logic is password-secured at the factory.
The SM2 module handles the Modbus communications between the PLC and other devices.
The Module Power Supply powers the Base Unit and the I/O modules. The remainder of the PLC rack is for the
discrete input and output modules, and for analog input module (optional).
I/O modules are used to send and receive control and communication signals to/from other parts of the system.
A Right End Cap Terminator is required to complete the modular communication bus. It attaches to the right side
of the last module in the rack.
An optional analog input module can be added to the PLC to provide additional functionality.
The HMI displays numerous boiler parameters at a glance and provides easy menu navigation for configuring
system parameters, setting of combustion, monitoring the boiler processes, and managing and annunciating sys-
tem alarms.
The HMI communicates with the PLC via Ethernet and is
powered by a 24 VDC din-rail mounted power suppl y .
NOTE: For complete information on the boiler control system consult the Hawk manual, provided separately.
1b 235
68 6
1
1a
7
9
4

750-392
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Component Locations
1.2.9 — Pressure Controls
1.Pressure Gauge: Indicates boiler internal pressure.
2.Operating Limit Pressure Control: Breaks a circuit to stop burner operation on a rise of
boiler pressure at a selected setting. It is adjusted to stop or start the burner at a prese-
lected pressure setting.
3.High Limit Pressure Control: Breaks a circuit to stop burner operation on a rise of pres-
sure above a selected setting. It is adjusted to stop the burner at a preselected pressure
above the operating limit control setting. The high limit pressure control is normally
equipped with a manual reset.
4.Pressure Transmitter: Senses changing boiler pressure and transmits a signal to the
boiler control system.
FIGURE 1-15. Steam Controls
FIGURE 1-14. Boiler Overview screen, Hawk 1000
1
2
3
4

Introduction
1-12 750-392
CBEX -DE
1.2.10 — Temperature Controls (hot water boilers)
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 the burner at a preselected temperature above the operating control setting. The
high limit temperature control normally is equipped with a manual reset.
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.
1.2.11 — Water Level Controls
The Low Water Cutoff (LWCO) shuts down the burner if water level goes
below the safe operating point. The LWCO is also responsible for starting
and stopping the feedwater pump to maintain the proper boiler water
level. The Cleaver-Brooks Level Master is the standard LWCO on CBEX-
DE boilers.
1.Low Water Cutoff and Pump Control: Float-operated control responds to the water
level in the boiler. It performs two distinct functions:
•Stops firing of the burner if water level lowers below the safe operating point. Energizes
the low-water light in the control panel; also causes low-water alarm bell (optional
equipment) to ring. Code requirements of some models require a manual reset type of
low water cutoff.
•Starts and stops the feedwater pump (if used) to maintain water at the proper operat-
ing level.
2.Water Gauge Glass Drain Valve: Provided to flush the gauge glass.
3.Vent Valve: Allows the boiler to be vented during filling and facilitates routine boiler
inspection as required by ASME Code.
4.Water Column Drain Valve: Provided so that the LWCO and its piping can be flushed
regularly to assist in maintaining cross-connecting piping and in keeping the float bowl
clean and free of sediment. A similar drain valve is furnished with the auxiliary low water
cutoff.
5.The Auxiliary Low Water Cutoff (ALWCO) stops burner operation in the event boiler
water drops below the primary low water cutoff point. May require manual reset in order
to restart the boiler after a low water condition.
FIGURE 1-16. Low Water Cutoff, Aux. Low Water Cutoff
Level Master safety features include float detection, routines for water column
blowdown and ALWCO testing, and an independent watchdog system for
shutdown in the event of microprocessor failure. An internal clock provides
time-stamped event logging for all blowdown cycles and alarm occurrences.
The Level Master keypad/display unit is mounted in the control panel next to
the Hawk HMI. A bar graph provides a continuous reading of water level,
while a two row backlit LCD display shows controller messages. The sensor
component is mounted in the water column and can be easily removed for
inspection or cleaning.
Expanded programming features can be accessed via RS-232 computer con-
nection.
For further information see the Level Master manual provided separately.
1
3
2
4
LWCO
ALWCO
5
FIGURE 1-17. Level Master
display

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Component Locations
1.2.12 — Bottom blowdown piping
Quick and slow opening valves are provided as standard for bottom blowdown. See Chapter 2 for procedure.
1.2.13 — Air Compressor
A side mounted air compressor provides atomizing air when burning #2 oil. It is started automatically by the
combustion control system. It includes the following components:
1. Air Pump Motor: Drives the air pump and an air cooling fan. The motor is started and stopped simultaneously
with the forced draft fan motor.
2. Air Pump: Provides air for atomization of the fuel oil.
3. Air Filter: The filter cleans the air supply prior to entering air pump.
4. Check Valve: Prevents lubricating oil and compressed air from surging back through the pump and air filter
when the pump stops.
5. Air-Oil Receiver Tank: Holds a supply of oil for lubricating the air pump. The receiver tank also separates lube
oil from the atomizing air before delivery to nozzle.
6. Lube Oil Level Sight Glass: Indicates the level of lubricating oil in the air-oil receiver tank.
7. Lube Oil Cooling Coil: Cools the lubricating oil before it enters the air pump. A fan driven by the air pump
motor circulates cooling air over the coil.
8. Lube Oil Fill Pipe and Strainer: Used when adding oil to the air-oil receiver tank.
FIGURE 1-18. Air compressor
1
2
3
4
5
7
8
6

Introduction
1-14 750-392
CBEX -DE
1.2.14 — Safety Valve(s)
Safety valves prevent pressure in excess of the
design pressure of the 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 accumu-
lation of foreign material around the valve seat.
Apply only a moderate amount of pipe com-
pound to male threads and avoid over-tighten-
ing, 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.
The vent pipe should be supported so as to
ensure no pressure is exerted on the safety valve discharge piping.
Only properly certified personnel should adjust or repair the boiler safety valves. Failure to follow these instructions
could result in serious injury or death.
FIGURE 1-19. Safety Valve Piping
!Warning

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CHAPTER 2 Waterside Care
The operator should be familiar with this chapter before attempting to place the unit into operation.
Although it is of prime importance, the subject of water supply and treatment cannot thoroughly be covered
within the scope of this manual. For additional assistance with your water treatment needs, contact your Cleaver-
Brooks service and parts representative. Ultimately a water treatment expert should be consulted to obtain the
best treatment plan for your location.
Feedwater equipment should be ready for use upon installation of the boiler. Be sure that all valves, piping, boiler
feed pumps, and receivers are installed in accordance with prevailing codes and practices.
Strict attention to waterside care is essential during initial commissioning and throughout the lifetime of the
boiler. When placing the pressure vessel into initial service, keep in mind that the waterside of new boilers and
new or remodeled steam systems may contain oil, grease or other foreign matter. A method of boiling out the ves-
sel to remove the accumulations is described later in this chapter.
2.1 — Water requirements - steam boilers
Feed Pump Operation
Before turning on the pump motor be certain that all valves in the water feed line are open to prevent possible
damage to the feed pump mechanism. After opening the valves, momentarily energize the feed pump motor to
establish correct pump rotation. With the correct rotation established, close the boiler feed pump entrance
switch. The pump should shut down when the water level reaches the proper level.
Feedwater pumps must have adequate capacity to maintain required water level under all operating conditions.
Check the feedwater pumps periodically and maintain as necessary to prevent unexpected breakdowns.
NOTE: Prior to operating the pump, carefully check the alignment of the flexible coupling, if one is used. A properly
aligned coupling will last a long time and provide trouble-free mechanical operation.
NOTE: For new installations a startup strainer is recommended. Contact the pump manufacturer for details.
NOTE: In the event that water column isolation valves are provided, it must be established that the valves are open
and seated or locked in the open position. It is illegal to operate the boiler with closed or unseated open valves.

Waterside Care
2-2 750-392
CBEX-DE
2.2 — Water requirements - hot water boilers
Air Removal - The hot water outlet includes a dip tube which extends 2 to 3 inches into the boiler. The dip tube
reduces the possibility of air, which may be trapped at the top of the shell, from entering the system. Oxygen or
air released in the boiler will collect or be trapped at the top of the boiler shell.
The air vent tapping on the top center line of the boiler should be piped into the expansion or compression tank.
Air trapped at the top of the boiler will find its way out of the boiler through the tapping.
Minimum Water Temperature - The minimum recommended boiler water temperature is 170 deg F. When water
temperatures lower than 170 deg F are used, the combustion gases are reduced in temperature to a point where
water vapor condenses, causing corrosion in the boiler and possible breeching. Condensation is more severe on a
unit that operates intermittently and which is greatly oversized for the actual load. Condensation can be mini-
mized by maintaining boiler water temperatures above 170 deg F.
Notice
References to hot water boilers in this manual apply only to boilers using 100% water. Glycol solutions have
different operating requirements, circulation rates and temperatures, etc.
Rapid Replacement of Boiler Water - The system layout and controls should be arranged to prevent the possibil-
ity of pumping large quantities of cold water into a hot boiler, which will cause thermal stresses. Water tempera-
ture in a boiler of 200 deg F or 240 deg F cannot be completely replaced with 80 deg F water in a few minutes
time without causing thermal stress. The same fact applies to periods of normal operation, as well as during ini-
tial start-up.
The circulating pumps should be interlocked with the burner so that the burner cannot operate unless the circu-
lating pump is running in order to avoid damage to the equipment.
When individual zone circulating pumps are used, it is recommended that they be kept running-even though the
heat users do not require hot water. The relief device or by-pass valve will thus allow continuous circulation
through the boiler and can help prevent rapid replacement of boiler water with cold zone water.
Continuous Flow Through the Boiler - The system should be piped and the controls arranged to allow water cir-
culation through the boiler under all operating conditions. The operation of three-way valves and system controls
should be checked to be sure that the boiler will not be by-passed. Constant circulation through the boiler
eliminates the possibility of stratification within the unit and results in more even water temperatures to the sys-
tem. A rule of thumb of 3/4 to 1 gpm per boiler horsepower can be used to determine the minimum continuous
flow rate through the boiler under all operating conditions. The operator should determine that a flow of water
exists through the boiler before initial firing or refiring after boiler has been drained.
The isolation valves and the water column piping must be locked open during operation. Failure to do so may result
in a low water condition. Failure to follow these instructions could result in serious injury or death.
!Warning