Power Boiler Design, Inspection, and Repair

Power Boiler Design, Inspection, and Repair ASME Code Simplified Mohammad A. Malek, Ph.D., P.E. McGraw-Hill New York Chicago San Francisco Lisbon London Madrid Mexico City Milan New Delhi San Juan Seoul Singapore Sydney Toronto

ice xvii >duction xix ipter 1. Boiler Fundamentals 1.1 Definition 1.2 Steam Generation 1.2.1 Boiler flow diagram 1.2.2 Thermodynamics 1.2.3 Heat transfer 1.3 Boiler Classifications 1.3.1 Classification based on ASME code 1.3.2 Classification based on pressure 1.3.3 Classification based on output 1.3.4 Classification based on fuel 1.3.5 Classification based on materials 1.3.6 Classification based on use 1.3.7 Classification based on tube type 1.3.8 Miscellaneous boilers 1.4 Power Boilers 1.4.1 Power boiler 1.4.2 High-temperature water boiler 1.4.3 Miniature boiler 1.4.4 Electric boiler 1.4.5 Organic fluid vaporizer 1.5 Boiler Performance 1.6 Selection of a Boiler 1.7 International Code 1.8 Power Boiler Life Analysis 1.8.1 Useful life 1.8.2 Code requirements 1.9 Jurisdictional Authority 2. Materials 2.1 Production 2.1.1 Steel making process 2.1.2 Ferrous metals and alloys 2 2 2 3 4 6 6 7 8 8 8 9 9 11 11 11 12 13 13 14 14 15 16 18 18 18 19 21 22 22 24

vi Contents 2.1.3 Steel 2.1.4 Nonferrous metal and alloys 2.1.5 Forming shapes 2.2 Properties 2.2.1 Physical properties 2.2.2 Mechanical properties 2.2.3 Chemical properties 2.3 Application of Materials 2.3.1 Pressure parts 2.3.2 Nonpressure parts 2.4 Ordering 2.4.1 Standard 2.4.2 Size and tolerances 2.4.3 Code requirements 2.4.4 Purchase order 2.5 Receiving 2.5.1 Identification of materials 2.5.2 Receiving inspection reports 2.5.3 Mill test reports 2.6 Inspection 2.6.1 Markings 2.6.2 Transfer of markings Chapter 3. Boiler Design 3.1 Design Methods 3.2 Design Factors 3.2.1 Definitions 3.2.2 Design load 3.3 Cylindrical Parts under Stress 3.3.1 Longitudinal stress in a cylinder 3.3.2 Circumferential stress in a cylinder 3.4 Design of Boiler Components 3.4.1 Cylindrical parts 3.4.2 Dished heads 3.4.3 Unstayed flat heads and covers 3.5 Openings and Compensations 3.5.1 Small openings 3.5.2 Medium openings 3.5.3 Large openings 3.5.4 Compensation for openings 3.5.5 Steps in solving compensation problems 3.6 Stayed Surfaces 3.6.1 Stayed flat plates 3.6.2 Staybolts 3.7 Ligaments 3.7.1 Ligaments for definite pattern 3.7.2 Ligaments for indefinite pattern 3.8 Designer's Responsibilities 3.8.1 Operating conditions 3.8.2 Specifications

vii 3.8.3 Design calculations 100 3.8.4 Design Process 101 Chapter 4. Boiler Piping 103 } 4.1 Pipe Classifications 104-4.2 Power Boiler Piping 105 4.2.1 Boiler proper piping 108 4.2.2 Boiler external piping 108 t 4.2.3 Nonboiler external piping 110 ->' 4.3 Design Requirements 110 1 4.3.1 Piping under internal pressure 111 *" 4.3.2 Specific piping systems 115 *" 4.4 Materials 122 %^ 4.4.1 American piping standard 123 * '* 4.4.2 International standards 123 *' 4.5 Fabrication and Assembly 124 4.6 Shop Inspection and Testing 125 4.6.1 Stamping of pressure piping 125 4.6.2 Code symbol stamp 126 4.6.3 Manufacturer's data reports 126 4.7 Operation and Maintenance 127 4.8 In-service Inspection and Repair 127 ipter 5. Safety and Safety Relief Valves 129 5.1 Working Principle 130 5.2 Classifications 130 5.3 Materials 132 5.4 Capacity Requirements 134 5.4.1 Relieving capacity 134 5.4.2 Capacity checking 140 5.5 Design Requirements 143 5.5.1 Mechanical requirements 143 5.5.2 Boiler safety valves 144 5.5.3 Superheater and reheater safety valves 145 5.5.4 Organic fluid vaporizer safety valves 146 5.6 Safety Valve Manufacturing 147 5.6.1 Manufacturers 147 5.6.2 Capacity certification 148 5.6.3 Testing by manufacturers 152 5.6.4 Inspection and stamping 152 5.6.5 Certificate of conformance 154 5.7 Installation Requirements 155 5.8 Operation and Maintenance 156 5.9 Inspection and Repair 157 5.9.1 Inspection 157 5.9.2 Repairs 159

viii Contents Chapter 6. Fabrication 161 6.1 Preparation 161 6.1.1 Plates 162 6.1.2 Cylindrical shells 162 6.1.3 Formed heads 162 6.1.4 Tube holes 162 6.1.5 Holes for stays 162 6.1.6 Repair of defective materials 163 6.2 Fabrication by Welding 164 6.2.1 Design 165 6.2.2 Fabrication welding process 170 6.2.3 Loading on structural attachments 178 6.2.4 Inspection and tests 184 6.3 Fabrication by Brazing 186 6.3.1 Materials 189 6.3.2 Design 189 6.3.3 Fabrication 192 6.3.4 Inspection and tests 193 6.4 Assembly of Boiler 194 6.4.1 Shop-assembled boilers 194 6.4.2 Field-assembled boilers 194 6.5 Production of a Firetube Package Boiler 195 Chapter 7. Watertube Boilers 201 7.1 Working Principle 202 7.2 Classifications 203 7.2.1 Classification based on tubes' and drums' (structural) configurations 203 7.2.2 Classification based on use 206 7.2.3 Classification based on water circulation 208 7.2.4 Classification based on output 211 7.2.5 Classification based on erection 211 7.2.6 Classification based on special purpose 211 7.3 Main Components 215 7.4 Design Features 218 7.5 Construction of a Package Watertube Boiler 223 7.6 Specifying a Package Watertube Boiler 230 Chapter 8. Firetube Boilers 241 8.1 Working Principle 242 8.2 Classifications 242 8.2.1 Classification based on layout position 242 8.2.2 Classification based on type of firebox 247 8.2.3 Classification based on output 249 8.2.4 Classification based on type of erection 249 8.2.5 Classification based on special purpose 251 8.3 Main Components 251 8.4 Design Features 253 8.4.1 Shell and tubesheet thickness 256 8.4.2 Attachment of heads and tubesheets 256 8.4.3 Tubes 256

ix : 8.4.4 Combustion chamber tubesheet f 8.4.5 Furnaces l + 8.4.6 Fireboxes and waterlegs r 8.4.7 Stayed surfaces i'-' 8.4.8 Doors and openings 8.4.9 Domes f 8.4.10 Setting 1" 8.4.11 Piping, fittings, and appliances t' 8.4.12 MAWP for furnaces and tubes t" 8.5 Construction of a Firetube Boiler?* 8.6 Specifying a Firetube Boiler Npter 9. Feedwater Heaters f 9.1 Working Principle I* 9.2 Classifications i 9.2.1 Closed feedwater heater ^ 9.2.2 Open feedwater heater I 9.3 Materials Sv 9.4 Design Features ** 9.5 Operation ^ 9.6 Maintenance 9.7 Specifying a Feedwater Heater ttapter 10. Miniature Boilers It «f 10.1 Classification m 10.2 Design Features s«10.2.1 Washout openings?i 10.2.2 Feeding devices 10.2.3 Blowoff connections 10.2.4 Gage glasses p 10.2.5 Safety valves ' 10.2.6 Stop valves ^ 10.2.7 Pressure gages w. 10.3 Inspection and Stamping k 10.4 Controls and Safety Devices kj. 10.4.1 Automatic low water fuel cutoff I: 10.4.2 Electrical f 10.5 Specifying a Miniature Boiler Mpterii. Electric Boilers Ci1.1 Working Principle ^ 11.2 Classifications If 11.3 Design Features C 11.3.1 Sizing L 11.3.2 Pressure vessel l[f 11.3.3 Inspection openings C 11.3.4 Feedwater supply L. 11.3.5 Blowoff piping r 11.3.6 Water gages F 11.3.7 Pioina 258 258 265 266 271 273 273 274 275 284 285 289 289 289 290 292 295 295 297 298 298 301 302 303 304 304 305 305 305 305 305 305 306 306 306 307 309 309 310 312 313 314 314 314 315 315 315

11.4 Inspection and Stamping 316 11.4.1 Inspection 316 11.4.2 Hydrostatic test 316 11.4.3 Stamp holder 316 11.4.4 Stamping 317 11.4.5 Manufacturer's data reports 317 11.5 Controls and Safety Devices 317 11.5.1 Safety valves 317 11.5.2 Automatic devices 318 11.5.3 Low water fuel cutoff 318 11.6 Specifying an Electric Boiler 318 Chapter 12. Organic Fluid Vaporizers 321 12.1 Organic Fluids 321 12.2 Working Principle 322 12.3 Classifications 322 12.4 Design Features 324 12.4.1 Vaporizer shell 324 12.4.2 Gage glass 325 12.4.3 Drain valves 325 12.4.4 Hartford loop 325 12.4.5 Code reference 325 12.5 Inspection and Stamping 325 12.6 Controls and Safety Devices 325 12.6.1 Safety valve 326 12.6.2 Rupture disks 328 12.6.3 Level control 329 12.6.4 Temperature control 329 12.7 Operation 329 12.8 Specifying an Organic Fluid Vaporizer 331 Chapter 13. Shop Inspection 333 13.1 Boiler Fabrication Shop 333 13.1.1 Manufacturer 334 13.1.2 Manufacturer's responsibility 334 13.2 Authorized Inspection Agency 335 13.2.1 Qualification 335 13.2.2 Duties 336 13.2.3 Accreditation certificate 336 13.3 Authorized Inspectors 336 13.3.1 Qualification 337 13.3.2 Authorized inspector's responsibility 337 13.4 Inspection Tools 338 13.5 Inspections 338 13.5.1 The traveler 340 13.5.2 Code inspection 341 13.5.3 Field inspection 341 13.5.4 Visual inspection 342 13.5.5 Welding inspection 343 13.6 Nondestructive Examination 343 13.7 Hydrostatic Test 346 13.8 Hydrostatic Deformation Test 347

xi ipter 14. Stamping and Data Reports 14.1 Stamp Holders 14.1.1 Certificate of authorization 14.1.2 Agreement with authorized inspection agency 14.1.3 Quality control system 14.2 Code Symbol Stamps 14.3 Stamping 14.3.1 Shop assembled boilers 14.3.2 Field assembled boilers 14.4 Manufacturer's Data Reports 14.4.1 Types of data reports 14.5 Selection of Data Report Forms ipter 15. Auxiliaries and Appurtenances 15.1 Boiler Auxiliaries 15.1.1 Air system 15.1.2 Fuel systems 15.1.3 Steam system 15.1.4 Feedwater system 15.1.5 Draft system 15.2 Boiler Appurtenances 15.2.1 Safety and safety relief valves 15.2.2 Pressure gages 15.2.3 Water columns 15.2.4 Blowdown apparatus 15.2.5 Fusible plugs 15.2.6 Soot blowers 15.2.7 Boiler vents 15.3 Boiler Accessories 15.3.1 Blowoff tanks 15.3.2 Sample coolers 15.3.3 Flash economizers 15.3.4 Mist separators 15.3.5 Inline separators 15.3.6 Temperature regulating valves 15.3.7 Exhaust silencers pter16. FuelI Systems 16.1 16.2 f 18.3 Fuels 16.1.1 16.1.2 16.1.3 16.1.4 16.1.5 Gas Liquefied petroleum gas Fuel oils Coal Electricity Combustion 16.2.1 Types of combustion 16.2.2 Combustion process 16.2.3 Chemical reaction 16.2.4 Combustion air Fuel-Burning Systems 16.3.1 Burners 16.3.2 Pilots 349 350 350 352 352 355 356 357 359 360 362 362 365 365 365 366 369 372 377 379 380 380 382 382 383 383 383 383 383 385 385 385 385 386 386 387 387 388 388 389 391 391 391 393 393 394 394 395 395 395

xii Contents 16.4 Gas-Burning Equipment 16.5 Oil-Burning Equipment 16.6 Coal-Burning Equipment 16.7 NOx Control 16.7.1 NOx control technologies Chapter 17. Boiler Controls 17.1 17.2 17.3 17.4 17.5 17.6 pter 18. Boiler Installation 18.1 18.2 18.3 18.4 18.5 18.6 18.7 18.8 Basic Boiler Controls 17.1.1 Control loops 17.1.2 Application to boiler Burner Management Control Standards Controls and Safety Devices 17.4.1 Types 17.4.2 Minimum controls 17.4.3 Systems for multiple burners Installation Periodic Testing Boiler Installers Installation Code Boiler Room 18.3.1 Water and drain connections 18.3.2 Fire protection 18.3.3 Housekeeping 18.3.4 Posting the certificates 18.3.5 Record keeping 18.3.6 Safety Combustion Air Venting Boiler Placement Operation Tests Documentation Chapter 19. Boiler Operation 19.1 Operating Personnel 19.1.1 Boiler operators 19.1.2 Boiler engineers 19.1.3 Training 19.1.4 QFO-1 standard 19.2 Filling a New Boiler 19.3 Boiling Out 19.3.1 Simple boilout method 19.3.2 Stubborn boilout 19.4 Starting a Boiler 19.5 Condensation 19.6 Cutting in an Additional Boiler 19.7 Normal Operation

xiii 19.8 Boiler Shutdown 19.9 Periodic Tests 19.10 Boiler Room Emergency 19.11 Operation Logsheet ^Chapter 20. In-service Inspection 20.1 Authorized Inspectors 20.1.1 Qualification 20.1.2 Authorized inspector's responsibility 20.2 Boiler and Machinery Insurance 20.3 Inspection Tools 20.4 Boiler Inspection 20.4.1 First inspection 20.4.2 Routine inspection 20.5 Preparation for Inspection 20.5.1 Preparation for internal inspection 20.5.2 Preparation for external inspection 20.6 Inspection Types 20.6.1 Internal inspection 20.6.2 External inspection 20.7 Inspector's Calculations 20.8 Controls and Safety Devices Inspection 20.9 Repair Inspection 20.10 Certificates 20.10.1 Certificate of competency 20.10.2 Certificate of compliance tapter 21. Boiler Maintenance 21.1 21.2 21.3 21.4 21.5 21.6 21.7 21.8 Maintenance Personnel Maintenance Program 21.2.1 Routine maintenance 21.2.2 Preventive maintenance 21.2.3 Shutdown maintenance 21.2.4 Spare parts inventories 21.2.5 Personnel training 21.2.6 Boiler improvement Trouble-Shooting Maintenance Tools Tube Cleaning 21.5.1 Mechanical cleaning 21.5.2 Chemical cleaning Tube Expansion Preparing for Inspection Maintenance Logsheet ipter 22. Boiler Repairs 22.1 Repair Organizations 22.2 Repairs 22.2.1 Routine repairs 22.2.2 Major repairs 450 451 453 455 457 457 458 458 458 460 461 462 463 463 463 465 465 465 468 470 473 475 475 475 475 477 477 478 478 481 481 483 483 484 484 484 485 486 488 489 492 493 495 495 496 496 497

xiv Contents 22.3 Alterations 498 22.4 Rerating and Derating 498 22.4.1 MAWP for existing boilers 500 22.5 Repair Calculations 501 22.6 Repair Steps 502 22.6.1 Preparation 502 22.6.2 Authorization 503 22.6.3 Repair work 503 22.6.4 Welding 503 22.6.5 Heat treatment 504 22.6.6 Nondestructive examination 505 22.6.7 Materials 505 22.6.8 Repair inspection 505 22.6.9 Hydrostatic test 505 22.6.10 Repair nameplate 505 22.7 Repair Methods 506 22.7.1 Drum repair 506 22.7.2 Tube repair 508 22.7.3 Waterleg repair 509 22.7.4 Handhole repair 510 22.7.5 Stay repairs 510 22.7.6 Welded crack repairs 510 22.7.7 Seal welding of tubes 511 22.7.8 Reversed flange (ogee) repair 511 22.8 Documentation 512 Chapter 23. Water Treatment 515 23.1 Boiler Water 516 23.1.1 Water types 516 23.1.2 Formation of scale 517 23.1.3 Quantity of scale 518 23.2 Boiler Water Problems 518 23.2.1 Deposit problems 518 23.2.2 Corrosion problems 520 23.2.3 Foaming and priming 521 23.3 Testing of Water 521 23.3.1 Testing types 522 23.3.2 Recommended limits 523 23.4 Treatment Methods 523 23.4.1 External treatment 525 23.4.2 Internal treatment 530 23.4.3 Condensate treatment 532 23.5 Boiler Storage 533 23.5.1 Wet method 533 23.5.2 Dry method 534 23.6 Conclusion 535 Appendix A. Maximum Stress Values for Ferrous Materials 537 Appendix B. Maximum Stress Values for Nonferrous Materials 545 Appendix C. Dimensions of Plates 549

xv idix D. Dimension of Heads Appendix E. Pipe Thickness I Ifcppendix F. Tube Thickness i )pendix G. Charts for Components under External Pressure mdix H. MAWP for Watertubes mdix I. Manufacturers' Data Report for Watertube Boilers mdix J. Manufacturers' Data Report for Firetube Boilers mdix K. Manufacturers' Data Report for Miniature Boilers mdix L. Manufacturers' Data Report for Electric Boilers spendix M. Manufacturers' Data Report for Organic Fluid Vaporizer mdix N. Manufacturers' Data Report for Pressure Piping mdix O. Installing Contractor's Report for CSD-1 mdix P. First Inspection Report mdix Q. Suggested Format for Welding Procedure Specifications (WPS) idix R. Unit Conversions 551 555 557 559 563 565 569 573 577 581 585 589 593 597 601 Bibliography 607 Index 611