Attachment 6 - Cleaver-Brooks Boiler Manual.pdf

Cleaver-Brooks, Inc.

OPERATIONS & MAINTENANCE MANUAL

Prepared by: Cleaver-Brooks Engineered Boiler Systems

Page Intentionally Blank

TABLE OF CONTENTS

I. COMMENTARY

A. FOREWORD

B. CONSULTATION

C. INTRODUCTION TO CLEAVER-BROOKS PRODUCT LINE

II. BOILER AND APPURTENANCES

A. GENERAL DESCRIPTION

B. INSTALLATION

C. PRE-OPERATION

1. Preliminary

2. Hydrostatic Testing and Inspection

3. Cleaning and boiling out

4. Boilout procedure

D. SYSTEM CONTAMINATION

E. FEEDWATER SYSTEM AND TREATMENT

F. 'ABMA' STATEMENT FOR AUTO FIRING

G. PREPARATION BEFORE INITIAL FIRING

H. FILLING THE BOILER

I. ROUTINE OPERATION

1. Initial Firing

2. Daily Procedures

3. General

a. feedwater regulation and control

b. water level indication and control

c. the water column

d. blowdown

4. Maintenance

a. chemical feed system

b. steam gauge

c. control lines

d. observation ports

e. miscellaneous periodic inspection

5. Shutdown

a. annual (or longer) scheduled shutdown

b. pressure vessel care and repair

c. care of idle boilers

III. SPECIAL APPLICATION EQUIPMENT

A. SUPERHEATER

1. General

2. Boilout

3. Start-up Procedure

4. Shutdown Procedure

B. ECONOMIZER

1. General

2. Pre-installation

3. Installation

4. Operation

5. Operation with Corrosive Fuels

IV. MISCELLANEOUS

A. FLUE GAS RECIRCULATION

B. COLD WATER START

1. Hydrostatic Test

2. Boiler Boilout

3. Initial Startup

C. MANWAY PLATE JOINT SEALANT INSTALLATION

D. DISCUSSION OF "FREE-BLOW" VALVES

E. STEAM PURITY

V. PARTS ORDERING

A. GENERAL

Layup Procedure for long term storage included at end of the document

COMMENTARY

I. COMMENTARY

A. Foreword

This instruction manual is furnished to assist you in the operation and care of your Cleaver-Brooks equipment.

Some of the instructions are general and should be interpreted and applied with due consideration for the requirements of your particular operating conditions. They should supplement and not replace the experience and judgment of your operators upon whom sole responsibility for successful and safe operation exists. For specific information relating to sub-vendor supplied equipment, refer to the appropriate sub-vendor literature.

The service of a Cleaver-Brooks field service technician is usually furnished but is provided only if called for in the contract between the purchaser and Cleaver-Brooks should the customer desire the presence of a service technician, such service can be provided at a nominal per diem charge and will be provided upon the receipt of the purchaser's order requesting such service.

When the service of a Cleaver-Brooks technician is provided for the customer, it is for the purpose of aiding and training of the customer's personnel and not to replace them or to assume any of their duties. It should be understood that responsibility for operation rests solely with the customer's operators and Cleaver-Brooks assumes no responsibility for the customer's operator's failure to properly perform their respective duties. The presence of a Cleaver-Brooks service technician at the customer's location in no way relieves the customer's personnel of any of their responsibilities.

This instruction manual is provided to supply general and specific information on the installation, operation, and maintenance of this boiler system. However, not every contingency of installation, operation, and maintenance can be covered in any manual. Therefore, the owners operating and maintenance personnel should also be guided by generally accepted industry practices in the installation, operation, and maintenance of these boiler systems.

The contents of this instruction book describe and illustrate the installation, operation, and maintenance of the equipment furnished with the contract for which it is issued.

No equipment can remain in good operating condition if it is not inspected regularly and repaired and adjusted as required. For this reason, we recommend the appointment of a competent operator and/or maintenance technician to take direct charge of this equipment and to ensure that it receives proper attention at all times.

This instruction book should be given to the operators/maintenance personnel who will have charge of the operation and/or maintenance of the equipment.

This manual is not intended to cover all possible variations in operation or to provide for specific operating challenges that may arise. Should additional information be required, Cleaver-Brooks or its representative should be contacted.

No amount of written instructions can replace intelligent thinking and reasoning on the part of the operators.

This manual is not intended to relieve the operating personnel from their responsibility for the proper operation of the equipment. No attempt should be made to operate the equipment until the principals of operation and all of the components are thoroughly understood. Two important prerequisites to good operation are thorough understanding and an interest in the equipment.

Cleaver-Brooks engineers and service personnel do not carry local operator's licenses and, therefore, cannot relieve the customer's operators of their responsibilities with regard to local license and insurance company regulations.

A. Foreword – Cont'd

Before the boiler can be started up, Cleaver-Brooks representatives must be assured that the customer is fully insured against equipment failures or operational hazards. See "Pre-Start Up Report" for a list of items to be completed prior to start up.

The customer shall be responsible for complying with Labor Union demands, which may prevail during the start up, operation, or any work performed by Cleaver-Brooks personnel.

It is the responsibility of the owner to train and advise their personnel, as well as contractor personnel, regarding all aspects of the owner's safety requirements.

Cleaver-Brooks equipment is designed and engineered to provide extended and reliable service. The electrical and mechanical devices supplied are of the highest quality and selected because of excellent past performance.

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 combustible fuels. Therefore, proper operating techniques and maintenance procedures must be performed at all times. "Automatic" features included do not relieve operators of any responsibility; they merely free them from repetitions and provide more time for improving performance.

Because of local, state, or other applicable codes, there are numerous electric and safety devices, which vary considerably due to customer requirements and specific jurisdictions. Controls function satisfactorily for long periods of time and experience shows that some operators become lax in their scheduled tests and recordings, assuming normal operation will continue indefinitely. Malfunctions resulting in damage and economic loss can normally be traced to careless omissions regarding routine tests and recording of data.

It is recommended that a boiler log be maintained. Recording of readings and maintenance activities at scheduled times will be valuable in assisting adjustments, corrections, calibrations and repairs. Better knowledge and understanding of equipment will develop operator interest and attention to performance and log history. Periodic review of log records will assist operators in perfecting overall operation and will show areas requiring attention or corrections. Most instances of boiler damage result from operating the boiler at low water conditions. Operators must routinely check water levels by directly observing the gage glasses and by developing good testing procedures. All connecting piping and liquid level indicators and controls should be routinely inspected internally to assure free flow of water to all devices.

The waterside condition of the pressure vessel is extremely important. Waterside surfaces require frequent inspection to check for sludge, scale/hot spots, erosion and corrosion. The services of a qualified and competent water chemistry technician are a prerequisite to good waterside control and preventative maintenance.

The operation of this equipment by the owner's operating personnel must comply with specific regulations of the insurer and/or other jurisdictional authorities. In the event of a conflict between these regulations and the instructions contained herein, please contact Cleaver-Brooks representatives before proceeding.

Warning!

Do not allow anyone but fully trained and authorized personnel who fully understand all applicable sections of this manual and other specific sub-sections to operate, service, or repair this equipment.

Failure to follow all applicable warnings and instructions may result in severe personnel injury, fatalities or equipment damage.

B. Consultation

If you need consultation to solve a problem, you may contact either your local Cleaver-Brooks representative, Cleaver-Brooks Service department at (402) 434-2000 (8:00 AM to 4:30 PM CST) or the Engineered Boiler Burner Group Service Manager at (514) 329-6547 (8:00 AM to 4:30 PM EST ), Monday through Friday (except holidays).

Please have the following information when you call:

1. All Cleaver-Brooks drawings that relate to your problem. Please familiarize yourself with the equipment and question(s) before calling and provide a boiler serial number and specific drawing number(s).

2. A brief written description of the problem.

3. The nameplate data from your boiler.

4. A purchase order number in the event parts or a service call is required.

5. Shipping address. Air freight is available if required.

6. A telephone number, fax or e-mail address where we can contact you if we have to call back or provide documentation.

Cleaver-Brooks is interested in supplying you with any replacement parts for the equipment it has supplied.

Pricing is available upon request.

C. Introduction to Cleaver-Brooks Product Line

A portion of Cleaver-Brooks’ production is the manufacture of packaged water tube steam boilers consisting of three types: A, D, and O. These three types are generally discussed in this manual.

The steam generating components of the package are referred to as the pressure parts and consist of (in various arrangements) drums, tubes, and headers. The upper (steam) drum, located at the highest water level, contains internals for water supply, water chemical treatment and control, water level stability, steam separation, etc.

The lower (mud) drum is at the lowest point of the pressure parts and contains internals for mud (sludge) removal. The drums are connected by tubes of plain (non-finned) type. Tubes that feed water to the lower drum are called downcomers. Tubes having steam/water (two phase) mixtures are called risers. This flow of water in downcomers to the lower drum and through risers to the steam drum is referred to as natural circulation. Natural circulation results from the difference in density between heated water (containing steam bubbles) and unheated water completely in the liquid state. The two-phase (water-steam) mixture has a lower bulk density and seeks to rise. The single phase (completely liquid) water has a higher bulk density and seeks to lower area (mud drum) of the boiler.

The pressure parts consist of one (or two, for an A type boiler) integral superheater(s) when superheated steam is specified. First is the furnace where combustion occurs. Second is the tube (convection) bank where hot gases pass around the tubes. Saturated steam is generated in these first two sections. Third is a convective, radiant, or combination superheater which raises steam temperature above saturation temperature.

C. Introduction - Cont'd.

Fuel/Air mixtures ignited in the furnace result in radiant, convective, and conductive heat transfer. The hot gas consisting primarily of carbon dioxide, nitrogen, and water vapor is referred to as the products of combustion.

The furnace is surrounded by 5 or 6 water cooled walls consisting of plain (sometimes tangent) or membrane finned tubes backed by refractory, insulations, or ceramic fiber as required by specific design. Heat transfer into furnace tubes is both radiant and convective. This area, consisting of riser tubes, is the primary source of two phase steam/water mixture. The other major source of heat transfer is from hot gases that have exited the furnace into the tube (convection) bank. Gas exiting the tube bank, referred to as flue gas, may pass through another heat exchanger such as an economizer, or go directly to a stack prior to entering the atmosphere. The third form of heat, conductive, is that which escapes the envelope and is lost to the surrounding environment.

There are two distinct and separate sides of the pressure parts. The outside, where combustion and hot gases exist is referred to as the gas side. The inside, where water and steam exist is called the water side. If the two sides ever meet (it is called a leak) and will be the result of incorrect operation or inadequate maintenance. This instruction manual provides the owner with guidelines for correct operation and care of the equipment. Another excellent source addressing specific questions is Recommended Guidelines for the Care of Power Boilers, ASME Section VII. This publication is available from The American Society of Mechanical Engineers, 345 East 7th Street, New York, NY 10017.

BOILER AND APPURTENANCES

II. BOILER AND APPURTENANCES

A. General Description

The Cleaver-Brooks packaged water tube boiler is a complete steam generating system. It is a two pass design consisting of a furnace subjected to radiant heat of combustion and hot gases that travel the length of the furnace, then make one 180 turn into the second pass convection section. The gases exit the boiler at the flue gas outlet.

To more fully understand the term "packaged", operators should familiarize themselves with terms and descriptions of equipment that constitute the package. In addition to the boiler, briefly discussed in the introduction and above, are the following:

Burner Assembly Located in the approximate center of the furnace front wall. It is the device contained in a windbox which mixes fuel and air, and injects and ignites the mixture to produce heat. Refer to the burner section for complete details.

Forced Draft Fan & Drive This device, through controlling air flow, provides the proper amount of air required to support combustion of the fuel. The fan provides positive pressure from its discharge through all passages of flow to where flue gas enters the stack or other exhaust equipment. It may be mounted on the burner assembly or separately floor mounted. The motor may be directly connected to the fan wheel or coupling connected to the fan shaft. Fan shaft may incorporate housing mounted bearings or independent pedestal type bearings. The fan may include inlet vortex or outlet damper air control, inlet silencer, and connecting ductwork from fan to windbox. Refer to the fan section (or burner) for complete details.

Water Column and Attachments: The gauge glass is used to visually determine the water level in the boiler steam drum. This device is one of the most important accessories used for safe boiler operation. Therefore, it should be well lighted for visibility and checked regularly for accuracy. Water level alarms and cutoffs, internal or separate devices, are additional accessories used for safe boiler operation. All of these devices are intended to provide safe boiler operation. To ensure proper operation, they should be blown down each shift or at least daily to remove sediment, deposits, etc.

Feedwater Level Control: This device, sometimes coupled to other controllers, senses fluctuating steam drum water level (and sometimes steam flow and feedwater flow) and operates the feedwater control valve to vary the supply of water to the drum. A constant water level is the intended result.

Non-Return Valve (or Steam Stop-Check): Located directly at the outlet of the steam drum (or superheater, when there is one), it is used to automatically prevent back flow of steam (from other boilers in the system) into this boiler. It can also be manually closed to isolate the boiler from the steam header system.

Steam Drum Vent Valve: Located on the top of the steam drum, it vents air and gas from the pressure parts during startup. It can be used to relieve pressure before opening drum manholes or other pressure part access.

It is opened to alleviate a vacuum, created by condensing steam, when unit is cooling.

Chemical Feed Connection: This connection is usually on the steam drum (front or rear) and is piped from the chemical feed pump(s). It introduces chemicals directly into the treated boiler water and its internal stainless steel pipe has multiple fractional holes for proportional distribution.

Safety Valves: These valves are located on top of the steam drum (and at the superheater outlet when a superheater is supplied). They safely relieve steam when the internal pressure exceeds specific set points and close when acceptable pressure is established.

A. General Description - Cont'd.

Continuous Blowdown: A fractional multi-holed pipe extending a specified distance into the steam drum and located below the normal water level where suspended solids are in high concentration. These suspended solids are removed by an adjustable setting flow control (metering) valve. The adjustable flow reduces solids concentrations to predetermined and measurable levels. Without this metering valve, solids concentrations would continue rising to unacceptable levels as steam exits the outlet. This metering flow control valve can be manually adjusted as solids concentrations change.

Bottom Blow-Down Valves: These valves are located at the bottom of the mud (water) drum at burner (and/or) target ends, depending on drum length, and provide the means to dispose of sediment precipitated from evaporating water. Headers (when supplied) may also incorporate blowdown valves.

Sootblowers: When required by fuels fired, sootblowers at front (and/or rear) are installed in the convection section of the boiler. Sootblowers remove soot and ash from tubes, using high pressure steam or air. Operator performance and fuels fired dictate frequency of blowing.

Observation Ports: Located in the target (rear) wall and on the burner they provide a clear view of the burner flame, its shape and color pattern. Rear observation ports may be air cooled. Their slide gate valve design allows lens cleaning while boiler is operating.

B. Installation

It is not within the scope of this manual to provide detailed installation instructions which should be in accordance with specifications of the architect, engineer, or contractor. Good engineering practices must prevail. The following discussion covers areas of general concern.

Installation is generally in accord with certain codes and jurisdictions. Proper authorities should be consulted regarding the permanent installation of the boiler room and its support structure, steam venting both temporary and permanent during tests or emergency conditions, fuel supply piping and storage, electrical services, air supply, other piping such as water, steam, bottom blowoff and drains. All applicable permits, licenses, and insurance for construction, testing, and operation must be obtained, including stack permits if applicable.

When the boiler is received, it should be given a thorough inspection by a competent individual to determine if any damage has occurred during transit. External inspection will indicate any obvious damage. The boiler must be inspected internally as well. Bracing or shoring used to protect burner throat, tile, refractories and insulations during shipment are to be removed and checks made for cracking and loose, broken, or missing tile and refractory. Necessary repairs must be completed prior to proceeding. All boxes and crates should be carefully unpacked and checked against packing slips which will be found with each container. In case of any damage or shortage, the carrier is to be notified immediately, make a written report of all problems, include any photos taken, and file necessary claims.

When the boiler is connected to its auxiliaries, check for allowance of thermal growth of various pressure part connections, such as main steam outlet, mud drum blow-off lines, safety valves and their exhaust piping, drains, etc. Provisions for thermal growth include expansion joints, pipe hangers and rollers, pipe loops, and other means of support. Each connection should not exceed its allowable static load, forces, and moments. Due to potentially severe thermal shock, the mud drum blowoff lines should be piped individually to the blowoff tank/sewer system. All superheater drain lines should be piped independently to blowoff/sewer systems to prevent any potential back flow of condensate into the superheater. Superheater vents should be piped to a visible atmospheric exhaust so that visual assurance of flow by the operator is always seen.

B. Installation - Cont'd.

Electrical wiring, wire size, and necessary conduit, junction boxes, switches, feed boxes, circuit breakers, disconnects, starters, etc. need to be in accordance with applicable codes, installed properly and operable. The same applies to instruments, controls, air requirements and all other auxiliaries.

The forced draft fan must be checked for proper rotation and alignment. Since this is a pressurized system, the fan can be cold run and all flanged connections, joints, casing, etc. can be checked for tightness. The fan damper should be closed enough to create sufficient resistance to prevent the motor circuit breaker from overloading. Structural steel, grouting, base plates, duct work and supports, expansion joints, stacks, platforms and ladders should all be checked for proper installation and fit. This would include auxiliaries such as economizers, deaerators, pumping equipment, burners, control panels, fan inlet silencers, heaters, etc.

Field painting must not cover moving shafts, linkage, valve stems, thermal sensitive devices, name plates, or any component where paint could interfere with the normal operation of devices.

C. Pre-operation

1. Preliminary

The Cleaver-Brooks shop assembled unit has most of the boiler trim mounted in the shop, with the exception of the safety valves, vent valve, and blow-off valves, which are shipped separately for clearance purposes. Certain other trim items may also be disassembled for clearance purposes;

however, this material will be boxed and tagged. The general arrangement and/or arrangement assembly drawing of the unit will show where these accessories need to be remounted.

During fabrication, every precaution has been taken to keep foreign matter out of the tubes. It often happens that such items may enter the tubes between the time the boiler was fabricated and the time when it is ready to be operated. In view of this, it is recommended that prior to startup technician's arrival, all the tubes in the unit be inspected and cleaned out by a high pressure air or water hose. The manhole covers in the boiler should be opened and the hose introduced from the top drum through every tube - to be certain that no loose material or debris is lodged in any of the boiler tubes.

If it is possible, the hose should be pushed through every furnace tube in particular and through every target wall and boiler tube.

Where a tube turbine has been purchased, this turbine can be run through every tube. One man should measure the length of the tubes (from the steam drum) and ensure that the end of the turbine does not come thru into the mud drum. After running the tube turbine thru each tube (from the steam drum) down to about 2 feet from entering the mud drum, then a man enters the mud drum and pushes the turbine up the tubes to “short punch” the remaining tube length.

C. Pre-operation - Cont'd.

2. Hydrostatic Testing and Inspection

The boiler is constructed in accordance with the ASME Boiler & Pressure Vessel Code, Sec. I and was hydrostatically tested in Cleaver-Brooks’ manufacturing facility in accordance with sub-section PG-99 "Hydrostatic Test." Copies of the Manufacturers' Data Reports, signed by the inspector witnessing and evidencing the test, have been forwarded to all jurisdictional bodies as well as to the boiler owner. To be sure that the pressure parts are still tight following shipment and installation, the owner may require a hydrostatic test to be conducted as soon as possible after installation. This test will generally be done under the supervision and witnessed by an authorized inspector who may represent either the state or municipality having jurisdiction or the insurance company covering the installation.

At the option of the inspector, this test may be at 1-1/2 times the design pressure of unit, or at a pressure slightly less than the setting of the lowest safety valve. The latter test will avoid the necessity of blanking or gagging safety valves, removing piping and plugging various pipe openings, removing controls and gauge glass, etc. Under no conditions should the steam drum or superheater safety valves be lifted with water.

Before starting a test, make sure that all foreign material, tools, etc, are removed from the boiler by playing high pressure water into the drums, tubes, nipples and headers. Assure all personnel are out of pressure parts and then install manhole covers, including new gaskets. Depending upon the test pressure, be sure to blank off any part that is not designed to withstand the pressure to be developed.

This will include water column, gauge glass, feedwater regulators, steam pressure gauge, pressure controls, etc. Safety valves, in this case, must be blanked or gagged.

All connections on the boiler should be closed with the exception of the vent, pressure gauge, and feed line through which pressure will be applied. A pressure gauge of adequate range should be dead weight calibrated to ensure gauge accuracy. The gauge should be temporarily connected to the steam drum vent valve as shown in Fig. 7.

When the boiler is ready for the test, it should be filled with water of a temperature not less than ambient and in no case less than 70F nor hotter than 120F. Care should be taken so that all air is vented while the boiler is being filled.

If a superheater is supplied, fill it first in accordance with the supplemental superheater instructions.

Fill the boiler until water flows from the bleed valve. Close the bleed. Treated boiler feedwater should be used when available.

Apply pressure slowly. The recommended rate of pressure increase is less than 50 psi per minute.

Proper control must be maintained so that pressure does not exceed the desired setting. When this test pressure is reached, inspection in accordance with the test objective can begin.

Once 1-1/2 times the design pressure is reached, this pressure shall be properly controlled so the 1-1/2 times design pressure is never exceeded by more than 6 percent. The pressure can often then be reduced to design pressure and the boiler inspected for leaks. Weeping tubes (shows some wetness but no water flow) are not considered leaks and will seal when operating temperature is reached. To avoid invalidation of warranty all leaks should be reported to Cleaver-Brooks prior to making any repairs.

Upon completion of the test, release pressure slowly through a small drain valve. Then fully open vents and drains. Particular care must be given to make sure that parts not normally containing water during operation, such as the superheater or circulating tubes above normal water level are drained free of water.

C. Pre-operation - Cont'd.

If temporary handhole or manhole gaskets were used for the test, they should be replaced with regular service gaskets before readying the unit for operation. Gaskets should never be reused. Replace gauge glass if necessary and make sure that gauge glass isolation valves (cocks) are open.

CAUTION!

Remove all blanks or gags from safety valves.

Additional inspection at this time, by the authorized inspector, will determine whether the installation:

including piping arrangements, valves, gauges and controls and other equipment on the boiler, meet Code and/or other jurisdictional requirements.

3. Cleaning and boiling out

The primary purpose of initial firing, or boil-out, is to dry and cure the furnace refractory and to remove foreign material from the water side of the pressure parts. In addition, this is the time to inspect the boiler casing for flue gas leaks or other problems that may become apparent.

The drums, before assembly, have been cleaned to remove any oil or foreign material that may have adhered during the fabricating process. The tubes are clean when received from the fabricator but in the bending process a solution is introduced into the tubes to lubricate the tube bending mandrel.

When expanding the tubes into the drum, a lubricant is applied to the tube expanders. All these foreign materials can be removed by performing an alkaline boil-out of the pressure parts.

Before the boil-out procedures can begin, the boiler should be ready for firing and the operator must be familiar with the operation of the burner and controls and thoroughly understand all instructions contained in the burner and control sections of this manual. The Pre-Start-Up Report in this manual must be filled out, signed and given to the boiler start-up technical supervisor.

Always fill the boiler with water at a temperature 25-50F higher than the ambient metal temperature of the boiler pressure parts.

If water colder than 70F is to be used for boil-out and/or startup and initial running, Cleaver-Brooks must be notified prior to proceeding. A temporary water heater, electric or steam coil, should be used if possible. Heating of cold water in the pressure parts must be done slowly. Use of the burner pilot may be considered. Burner operation, even intermittently at low fire, may cause an excessive metal temperature differential between cold water (inside) and hot gases (outside) resulting in damage to pressure parts and voiding the warranty.

When starting up the boiler and putting it into operation, the most important thing, second to no other item to be considered, is water level. It is assumed that the devices for feeding water into the unit are in operation, and it is of the utmost importance that the water level in the unit be carried at approximately half level in the water gauge glass. A drawing of the particular boiler concerned will show where the water level should be carried under normal conditions. A variation of three inches above or below this water level is tolerable, but is not recommended.

C. Pre-operation – Cont'd.

The caustic chemicals used in boil-out require special care, both in liquid and vapor states, to avoid personal injury. The customer is liable for the disposal of all chemical solutions once their use is complete. These solutions can damage drum manway gaskets and water column sight glasses requiring their replacement. Cleaver-Brooks provides replacement gaskets and a tubular sight glass for use during boil-out. This glass has a low pressure rating (250 PSIG max) and care must be taken not to exceed this pressure. The glass must be replaced before the boiler is operated at rated pressure.

4. Boilout procedure

The following instructions are to be performed under the supervision of a factory trained representative.

A new boiler must be boiled out with a solution of suitable chemicals to thoroughly cleanse the internal surfaces. Petroleum based products may accumulate during fabrication which could cause foaming, water carryover, and possible equipment damage.

THE PROPER BOIL OUT PROCEDURE MUST BE DETERMINED BY THE COMPANY THAT

WILL HANDLE THE CHEMICAL TREATMENT OF THE UNIT. ANY RECOMMENDATIONS

FROM THE MANUFACTURER MUST BE INTERPRETED AS BEING MERELY

SUGGESTIONS AND IN NO WAY CONSTITUTE A MANDATORY REQUIREMENT.

Prior to commencing the boil out, the following needs to be checked:

a) Boiler drums should be inspected internally and all foreign material removed.

b) To ensure thorough cleaning, all drum internals should be tightly in place and not obstructing tube openings.

c) It is suggested that a temporary gauge glass be installed during the boil-out operation when a prismatic or flat gauge glass is furnished.

d) Fill the boiler with water at or above ambient temperature to a point 2" below the manhole opening in the steam drum.

e) The superheater is to be kept dry (not filled with water) during boil-out.

f) When proper quantities of chemicals have been added, close all steam drum openings.

g) For saturated boilers, fill boiler to normal steaming level (one half glass). For superheated boilers, refer to section III.A.2.

h) Open the steam drum vent valve or, if the boiler is equipped with a superheater, open the superheater outlet vent valve. Recheck the burner, feedwater supply, gauge glass, pressure gauge, and the position of all valves.

i) Set high steam pressure cut out to operating pressure, but not to exceed 150 PSIG.

All safety devices relative to fuel, water and steam systems must be in operable conditions

j) After the boil-out, inspect the drums and wipe out any sludge or scum that may be present. Then wash out boiler thoroughly with a high pressure hose, using water of approximately 70F temperature, or ambient. Use a hose on each individual tube including superheater and economizer tubes. The fireside of the boiler should be checked for any unusual conditions.

k) Upon completion of the wash down, inspect the internal surfaces and if not clean, repeat the boil-out.

l) Replace manhole covers and install new manhole gaskets. Replace the gauge glass if necessary.

Reinstall the prismatic (or flat) gage glass if boiler is so equipped.

D. System Contamination

Steam and water piping systems connected to the boiler may contain oil, grease or foreign matter. In new systems, the piping usually has an accumulation of oil, grease, weld slag and dirt. Old systems have an additional hazard in that the piping and receivers may be heavily limed and full of scale as the result of improper water treatment.

These impurities must be prevented from entering the boiler. On a steam system, the condensate should be wasted until tests show the elimination of undesirable impurities. During the period that condensate is wasted, attention must be given to the treatment of the water used as make-up, so that an accumulation of unwanted materials or corrosion of drums and tubes does not occur. Follow the advice of your water treating company.

Consult with water treatment companies for recommendations, cleaning compounds and for application procedures.

If oil, dirt and scale accumulations are permitted to get into the boiler, it may be necessary to repeat the boil-out procedure. If this becomes necessary, the same procedure as outlined under boil-out should be followed.

The waterside of the pressure vessel must be kept clean from grease, sludge and foreign material. Such deposits, if present, will not only shorten the life of the pressure vessel and interfere with efficient operation and functioning of control or safety devices, but could cause unnecessary and expensive re-work, repairs and down time.

The pressure vessel waterside should be inspected on a periodic basis. This will reveal true internal conditions and serve as a check against conditions indicated by chemical analysis of the boiler water. Inspection should be made three months after initial starting and at regular 6, 9 or 12 month intervals thereafter. The frequency of further periodic inspections will depend upon the internal conditions found.

If any unwanted conditions are observed, your water consultant or water treating company should be contacted for recommendations.

Any sludge, mud or sediment found will have to be flushed out. The effectiveness of the blowdown practiced on steam boilers will be verified and scheduling or frequency of blowdown may have to be revised. The need for periodic draining or washout will also be indicated.

E. Feedwater System and Treatment

The subject of water supply and treatment is of great importance and it can not be adequately covered in this manual. Maximum effectiveness and long trouble-free life of the pressure vessel are functions of properly treated water. The type and extent of water treatment is determined by the water supply. The services of a reliable boiler water treatment specialist or company should be engaged to analyze the water and prescribe treatment. Their recommendations should be followed rigidly to prevent the presence of unwanted solids and corrosive gases. Failure to do so will result in ever decreasing boiler efficiency as well as shortened useful life.

Objectives of water treatment in general are:

1. Prevention of hard scale deposits or soft sludge type deposits, which impair the rate of heat transfer and can lead to overheated metal and costly down time and repairs.

2. Elimination of corrosive gases, in supply or boiler water.

3. Prevention of intercrystalline cracking or caustic embrittlement of boiler metal.

4. Prevention of carryover and foaming.

The accomplishment of these objectives generally require treatment before and after introduction of water into the boiler.

The selection of pre-treatment processes depends upon water source, chemical characteristics, amount of make-up water needed, plant operating practices, etc. These treating methods include filtering, softening, demineralizing, deaerating and preheating.

After treatment involves the addition of chemicals to the boiler water. This after treatment is required to compensate for any variations in the pre-treatment and pre-boiler system and to assure the ultimate protection of the boiler. Because of the variables involved, no one "boiler compound" can be considered a cure-all, nor is it advisable to experiment with home-made treating methods. Sound recommendations and their employment should be augmented by periodic analysis of the raw water, boiler water and condensate.

The internal or waterside surfaces of the pressure vessel should be inspected with sufficient frequency to determine the presence of any contamination, accumulations of foreign matter, corrosion, and/or pitting. If these conditions are detected, the water consultant or feedwater treatment company should be consulted for advice on corrective action.

It is advisable to have a properly sized water meter installed in the raw water make-up line to accurately determine the amount of raw water admitted to the boiler. This will aid the water treatment program in maintaining proper waterside conditions.

Suggested Water Chemistry Limits Industrial Watertube, High Duty, Primary Fuel Fired, Drum Type

Makeup water percentage: Up to 100% of feedwater Conditions: Includes superheater, turbine drives, or process restriction on steam purity Saturated steam purity target: See tabulated values below.

* as CaCO3 NS = not specified ND = not detectable VAM = Use only volatile alkaline materials upstream of attemperation water source. (10)

Notes to Table:

(1) With local heat fluxes >1.5 x 105 Btu/hr/ft2 (>473.2 kW/m2), use values for at least the next higher pressure range.

(2) Minimum hydroxide alkalinity concentrations in boilers below 900 psig (6.21 MPa) must be individually specified by a qualified water treatment consultant with regard to silica solubility and other components of internal treatment. See section 6.6 of this document.

(3) Maximum total alkalinity consistent with acceptable steam purity. If necessary, should override conductance as blowdown control parameter. If makeup is demineralized quality water and boiler operates at less that 1000 psig (6.89 MPa) drum pressure, the boiler water conductance should be that in table for 100-1500 psig (6.9-10.34 MPa) range. In this case, the necessary continuous blowdown will usually keep these parameters below the tabulated maximum values. Alkalinity values in excess of 10% of specific conductance values may cause foaming.

(4) Not detectable in these cases refers to free sodium or potassium hydroxide alkalinity. Some small variable amount of total alkalinity will be present and measurable with the assumed congruent or coordinated phosphate-pH control or volatile treatment employed at these high pressure ranges.

(5) Maximum values are often not achievable without exceeding maximum total alkalinity values, especially in boilers below 900 psig (6.21 MPa) with >20% makeup of water whose total alkalinity is >20% of TDS naturally or after pretreatment by lime-soda, or sodium cycle ion exchange softening. Actual permissible conductance values to achieve any desired steam purity must be established for each case by careful steam purity measurements. Relationship between conductance and steam purity is affected by too many variables to allow its reduction to a simple list of tabulated values.

(6) Nonvolatile TOC is that organic carbon not intentionally added as part of the water treatment regime. See Section 6.4 of this document.

(7) Boilers below 900 psig (6.21 MPa) with large furnaces, large steam release space, and internal chelant, polymer, and/or antifoam treatment can sometimes tolerate higher levels of feedwater impurities than those in the table and still achieve adequate deposition control and steam purity. Removal of these

Drum Operating Pressure (1) (11)

Psig 0-300 (MPa) (0-2.07)

301-450 (2.08-3.10)

451-600 (3.11-4.14)

601-750 (4.15-5.17)

751-900 (5.18-6.21)

901- (6.22- 6.89)

1001-1500 (6.90- 10.34)

1501-2000 (10.35- 13.79)

Feedwater (7) Dissolved oxygen ppm (mg/l)O2

- measured before chemical oxygen scavenger addition (8)

< 0.007 < 0.007 < 0.007 < 0.007 < 0.007 < 0.007 < 0.007 < 0.007

Total iron ppm (mg/l) Fe < 0.1 < 0.05 < 0.03 < 0.025 < 0.02 < 0.02 < 0.01 < 0.01 Total copper ppm (mg/l) Cu < 0.05 < 0.025 < 0.02 < 0.02 < 0.015 < 0.01 < 0.01 < 0.01 Total hardness ppm (mg/l)* < 0.3 < 0.3 < 0.2 < 0.2 < 0.1 < 0.05 ND ND pH @ 250C 8.3-10.0 8.3-10.0 8.3-10.0 8.3-10.0 8.3-10.0 8.8-9.6 8.8-9.6 8.8-9.6 Chemicals for preboiler system protection

NS NS NS NS NS VAM VAM VAM

Nonvolatile TOC ppm (mg/l) C (6) < 1 < 1 < 0.5 < 0.5 < 0.5 < 0.2 < 0.2 < 0.2 Oily matter ppm (mg/l) < 1 < 1 < 0.5 < 0.5 < 0.5 < 0.2 < 0.2 < 0.2 Boiler Water Silica ppm (mg/l) < 150 < 90 < 40 < 30 < 20 < 8 < 2 < 1 Total alkalinity ppm (mg/l)* < 700(3) < 600(3) < 500(3) < 200(3) < 150(3) < 100(3) < NS(4) < NS(4) Free OH alkalinity ppm (mg/l)* (2) NS NS NS NS NS NS ND(4) ND(4) Specific conductance (12) µmhos/cm (µS/cm) 250C without neutralization

5400- 1100(5)

4600-900(5) 3800-800(5) 1500-300(5) 1200-200(5) 100- 200(5)

< 150 < 80

Total Dissolved Solids in Steam (9)

TDS (maximum) ppm (mg/l) 1.0-0.2 1.0-0.2 1.0 0.2 0.5-0.1 0.5-0.1 0.1 0.1 impurities by external pretreatment is always a more positive solution. Alternatives must be evaluated as to practicality and economics in each individual case.

(8) Values in the table assume existence of a deaerator.

(9) Achievable steam purity depends on many variables, including boiler water total alkalinity and specific and specific conductance as well as design of boiler steam drum internals and operating conditions [(Note 5)].

Since boilers in this category require a relatively high degree of steam purity for protection of the superheaters and turbines, more stringent steam purity requirements such as process steam restrictions on individual chemical species or restrictions more stringent than 0.1 ppm (mg/l) TDS turbine steam purity must be addressed specifically.

(10) As a general rule, the requirements for attemperation spray water quality are the same as those for steam purity. In some cases boiler feedwater is suitable; however, frequently additional purification is required. In all cases the spray water should be obtained from a source that is free of deposit forming and corrosive chemicals such as sodium hydroxide, sodium sulfite, sodium phosphate, iron, and copper. The suggested limits for spray water quality are < 30 ppb (µg/l) TDS maximum, < 10 ppb (µg/l) Na maximum, < 20 ppb (µg/l) SiO2 maximum, and it should be essentially oxygen free.

(11) Low pressure boilers frequently use feedwater that is suitable for use in higher pressure boilers. In these cases the boiler water chemistry limits should be based on the pressure range that is mose consistent with the feedwater quality. See Sections 1 and 6.2 of this document regarding blowdown.

(12) Conversion from ppm (mg/l) TDS values in the ABMA standards [12] used a factor of 0.65. See Section

6.7 of this document.

F. 'ABMA' Statement for Auto Firing

One of the accepted values to the owner of an automatically fired boiler unit is its operation by the use of automatic controls. Such controls reduce the amount of manual labor required, afford a consistently high degree of regulation, and therefore, contribute to the low cost of producing steam.

In order to obtain these advantages, purchasers and users of automatically fired boiler units must recognize that competent supervision and adequate maintenance is required for safe and dependable operation.

The automatic operation of such units does not eliminate the necessity of employing qualified operators.

Manufacturers of automatically fired boiler units do not assume any liability for injury to persons or damage to property which may be attributed to the operation of the equipment.

G. Preparation Before Initial Firing

The operator must be knowledgeable of the boiler, the burner and all controls and components and must be qualified to operate this equipment. The operating conditions of all auxiliary equipment and instrumentation that serves in the firing and feeding of the boiler should be formally checked out. Be sure that auxiliary equipment not supplied by Cleaver-Brooks is of adequate size and pressure to ensure proper operation.

Check for proper voltage, fuses and overloads. Check rotation of all motors by momentarily closing the motor starter or relay. Check the reset of all starters and controls having a manual reset feature. To the extent possible, all operating mechanisms, valves, air dampers and drives should be checked for proper operation and freedom from binding. Check the settings of all controls.

Verify fuel supply. Make certain that fuel pressure is sufficient and that gauges are indicating correctly.

Properly set any adjustable limit on interlock controls. Pretest them for proper function at set points if feasible.

Before operating a boiler feed pump or an oil supply pump, be sure that all valves in the line are open or properly positioned. Be certain that pump rotation is correct. If in doubt, remove coupling and check motor rotation. Some pumps can be severely damaged by even momentary reverse rotation. Also recheck coupling alignment.

Check out the burner in accordance with procedures given in the burner instruction manual. Safety valves should be inspected externally to see that they are free to operate and that their discharge and drain piping is open to atmosphere and free to expand without imposing stress on the safety valve body. Make sure that any gags used during testing are removed. Ascertain that discharge piping from the safety valves and also from all blowdown vent and drain valves is piped to a SAFE point of discharge, so that emission of hot water or steam cannot possibly cause injury to personnel or damage to property.

Prior to closing drum manholes, make certain that all internal fittings are in place and that no tools, gear or personnel remain inside. Make a final check of the fireside area to make sure no tools, construction gear, debris or personnel are present.

For safety's sake, make a final and complete pre-startup inspection, especially checking for any loose or uncompleted piping or wiring or any other situation that might present a hazard.

H. Filling The Boiler

Check and close the manual blowoff valves, the continuous blowdown valves, the gauge cocks and the water column and gauge glass drain valves.

Open the steam drum vent valve, the water column shutoff valves, if any, the gauge glass shutoff valves and the steam pressure gauge shut-off valve. Open the superheater vent and drain valves - on superheated units.

The boiler should be filled with properly treated feedwater using the bypass feed line. The water should be 25 - 50F above the metal temperature to prevent excessive temperature stresses that could cause tube leakage. 70F minimum water temperature is recommended unless ambient is considerably higher. Fill to normal level of half full gauge glass. Fill slowly and vent fully to prevent any pressure buildup from the flashing of hot feed water.

Blow down the water column and gauge glass, making sure that the water level returns to the proper level promptly. The gauge cocks, if supplied, should also be operated to verify water level.

The boiler is supplied with a feedwater controller and control valve. Their purpose is to automatically maintain the proper operating water level when supplied with the appropriate water pressure and flow. The control valve is supplied with a manual bypass for initial fillings or when otherwise necessary.

H. Filling The Boiler – Cont'd.

If the water supply is shut off during operation, the water level may drop 3-4 inches in a matter of minutes. The low water cut-offs will shut the burner off before the water level reaches a dangerously low level. Observe that the cut-offs are working properly and make any required corrections. The water level should be checked often to ensure the feedwater control system is working properly.

In the remote event that there is no water visible in the gauge glass and the burner is still operating, shut the burner off immediately.

Never add water until it has been determined the boiler has not been overheated by the low water condition.

I. Routine Operation

1. Initial Firing

There must be an unrestricted path for air flow from the forced draft fan inlet through the stack and into the atmosphere, excluding any air flow control dampers.

Remove boiler blocking and any debris from the furnace.