Tolley's Basic Science and Practice

of Gas Service Gas Service Technology Volume 1

ELSEVIER

Fourth edition

Edited by

Frank Saxon

Revised by

Route One Training and Development Limited

AMSTERDAM . BOSTON . HEIDELBERG • LONDON

NEW YORK . OXFORD. PARIS . SAN DlEGO

SAN FRANCISCO . SINGAPORE. SYDNEY. TOKYO

NeWJ>eS ;,; an imprint of Elscvier Newnes

Contents

Preface VJ

Properties of Gases 2 Combustion 14 3 Liquefied Petroleum Gas 43 4 Burners 90 5 Energy 122 6 Pressure and Gas Flow 162 7 Control of Pressure 199 8 Measurement of Gas 228 9 Basic Electricity 267

10 Transfer of Heat 323 11 Gas Controls 347 12 Materials and Processes 405 13 Tools 431 14 Measuring Devices 486

Appendix J SI Un its 511 Appendix 2 Conversion Factors 513 Index 517

v

Index

Absolute zero. 3. 132 Acceleration. 126 Adhesion, 172, J 73 Aerated flame, 26 Aeration, 10

control shuner, 91. 95 Air blast burners. 90 Air flow measurement. 497 Air movement. 138 Air required for combustion. 9, 14.

19.47 Air temperature, 138 Aldehydes. 36 Alien keys. 445 Alloys, 414 Alternating current. 285

frequency, 286 power factor, 321 rectification, 305 three-phase. 289 voltage. 287

Allitude. effect on pressure, 185 Aluminium. 48, 412 Ambient temperature, 332 Ammeter, 307 Anemometer. vane, 498

thenno,499 Aneroid barometer. 170 Aneroid gauge, 177 Angular velocity, 125 Annealing. 428 Anode. 270 Anodising, 426 Antimony, 412

517

Appliance perfonnance testers, 500

Asbestos, 421 regulations. 421 working precautions, 421

Atmospheric burners. 90 Atmospheric pressure, 167

effect of altitude. 185 measurement of. 171 standard cond itions. 168

Atmospheric sensing devices, see Oxygen depletion systems

Atom, components of. 14, 15 Atomic structure, 15.267,268 Automated reading system, 244 Automatic changeover

(LPG cylinders), 7 1. 72, 223 Automatic touch hold. 311 Axial flow turbine meter, 235

Baffles, 99 Bar (pressure unit), 166 Barometer, 168

aneroid. 170 Battery, 270 Beams, stresses in. 149 Bending machines. pipe, 470 Bending momenlS in joists and

beams, 149 Bending spring, 450 Bimeta1 strip thermostat, 376 Bimetallic devices. 357 Blowlamp, 451, 469

fuels, 429

518

Blow-off. 32 Blueing. 426 Boilers, 338 Bourden tube gauge, 179 Boyle's Law, 228 Bradawl,447 Brass, 414 British Gas multimeter. 308.460 British thermal unit. 122 Bricks. 419 Brittleness. 407 Brushes. 456 Building blocks. 419 Burner

body tapered, 101 components, 90 examples of. 116 head,91 location. 112 ports. 91, \0 1 pre·mix. 107

Butane. 11.44. 45. 49. 51 Butane/air mixture. 9, 11

combustion equations, 19,21 constituents. 20, 23 oxygen requirement. 20 pnxluCls of combustion, 2), 24 properties of, 13

Butane cabi net healer, 224 BUlylene, 44 Byelaws for water pipework,

413,415

Calorific value, 6, 12 Culorifiers. 339. 342 Capacitive reactance. 319. 32 1 CapaCitor, 295 Capillary attraction (Capillarity), 173 Carbon deposits, 35 Carbon dioxide. 11

flame/atmospheric effect, 41 Carbon monoxide, 6

flame/atmospheric effecl, 41 poisoning. 35

Carbon monoxide:carbon dioxide ratio, 37

Carbon steel tools. 412 Carburising. 42 Cartridge tools. 476 Case hardening. 429

INDEX

Cast iron. 410 Cata1ytie combustion burner. 110 Catalytic rich gas. 12. 13 Cathode, 270 Cathodic corrosion protection, 424 Celsius scale. 130. 131. 132 Cement, 419 Centigrade scale, 130 Central healing unit burner. 120 Centre of gravity, 157 Charger unit. 260 Charle.. .. · Law. 230 Chemical symbols, 5 Chisels. 433. 475 Choke (electrical), 319 Chromium. 412 Circuit breakers, 303

miniature, 304, 305 Circular saws, 474 Clasp knife. 455 Clothing. protective. 484 Cock. 347

faults. 349 Coefficient of cubical

expansion. 51 Cohesion. 172 Combustion. 14

analysers, 500 equation for, 19 flameless, 109 incomplete, 34 LPG.47 products of. 2 1. 22. 23. 24. 114 standards. 37

Comfort condilions. thermal. 137. 346

Commercial butane. 46 Commercial propane. 46

combustion equations. 21 constituents, 11 oxygen requirements. 19 products of combustion, 21, 23 properties. 12

Commutator. 288 Compounds. 16. 17 Concrete. 420 Condensation. 136 Conduction heat loss. 343 Conduction of heat. 324 Conductors. electrical, 267

Conservation of energy. 123 Constant pressure regulators. 202

compensated, 207 need for compensation. 206

Constituents of gases, 11 Containers (LPG). 52, 54, 58 Contents gauge, 76

iNDEX

Continuity bond. temporary, 318, 453 Control of pressure, 199

constant pressure regulalOrs. 202 district variations, 199 high-to-low pressure

regulators, 211 installing regulators, 215 LPG regulators, 212 methods, 200

Control systems. 400 electrically operated, 402 pressure operated, 40 I

Controlled atmospheres, 41 Controls

in domestic appliances, 347 multifunctional, 383

Convected heat now, 332 Convection, 323, 328

currents in room. 329 forced. 328 in liquid, 328, 329

Cooker hotplate burner. 116. 117 oven thennostat, 374 temperatures, 133

Copper. 413 Corrosion. 422

acid,422 atmospheric, 422 galvanic, 423 protection from. 424

Coulomb. 270 Crimping tools. 459 Critical pressure, 50 Critical temperature, 50 Cross-bonding to earth. 318 Cubic feci, 7 Current. electric. 270

induced magnetically, 284 magnetic effect, 281

Cylinder, hot water storage, 339 Cylinders, LPG, 58

automatic changeover, 71

design and construction, 58 regulators, 6{}, 61, 64, 79, 80 valves, 59 vapour offtake, 69

Deflectors, 91 Density. 7 Depanment of Trade and

Industry. 7 Descaling solutions. 429 Deuterium, atomic structure, 15 Dew point. 53, 137

butane/air, 55 Dielectric, 295 Dies. 449, 463 Diffusion, 3, 4 Digital multimeter. 460 Direct current, 270 Discharge rales (pipe). 196 Distribution of electricity, 289 Domestic intemal installation.

electricity, 291 Drilling tools. 437, 468 Drills and bits, 437, 438 Dry meter, 238 Dry pressure gauges, 177 Ductility, 407 Dust, explosive, 25 Dust sheets, 458 Dusting brushe.~, 457 Dynamics, 142 Dynamo, 288

E6 meter, 252 Earthing, 313 Elastic limit. 148 Elasticity,407 Electric capillary joint

maker, 459 Electric drill, 474 Electric motors, 283, 296 Electric shock, 311 Electrical circuits

resistances in series, 276 resistances in pantllel, 277

Electrical energy, 123,267,271 Electrical meters, 304 Electrical power, 271 Electrical supply coding, 314 Electricallools. 458

519

520

Electricity, 267 distribution, 289 domestic intemal

installation. 291 generation. 288

Electrolyte. 270 Electrolytic corrosion, 423, 424 Electromotive force. 271 EleclTons, 14, 15

flow of, 268 Electronic pulse/coil ignition, 398 Electra-plating, 427 Elements. 16 Emergency/meter control. 349 Emissivity. 335 Energy, 122

conservation of, 123 electrical. 267. 271 forms of. 122

Ethane. 11 Evaporation. 136 Excess air. 24 Explosion. 24

Fahrenheit scale, 130. 131 Families of gases, 9

comparison of properties. 12 Family 1 gas, 9 Family 2 gas, 9 Family 3 gas, 9 Farad,296 Faull diagnosis. 110, 402 Faul! voltage-operated circuit

breaker, 317 Ferrous metals, 409 Filament ignition/igniters. 39.

391. 394 Files, 439, 440, 468 Filling connection (LPG tank). 76 Fire-resistant mat, 451 First aid kit, 458 Fixed aeration, 94 Flame front. 28 Flame kemel, 39 Flame lift, 32, 34 Flame protection devices,

357. 383 flame rectification. 371 oxygen depletion systems, 365 photo-electric. 371

INDEX

thermal backflow prevention device (ITB), 368

thermo-electric, 361 vapour pressure. 359

Flame speed, 11 and acmtion. 25, 32

Flames. 26. 38, 40 fault diagnosis by, 110 oxidising effect, 40. 41 post-aemted, 26 pre-aemted, 26 reducing effect, 40

Flammability, 24 limits. 10, 52, 53, 55

Flash tube, 393, 394 Fleming's right-hand rule. 284 Flow measurement, 497 Flue brushes. 457 Flue gas analysis, 500 Fluke 75 digital multimCler,

310,460 series 2 model, 311

Fluxes Gointing), 430 Force. 127 Forced-dmught burners, 90, 108 Frequency, 286 Fuse, 303 Fusion of icc, latent heat of, 136

Galvanising, 427 Gas bills, 264 Gas fire bumer. 118 Gas laws, 228 Gas measurement see Measurement

of gas Gas modulus. 10 Gas pressure. 187 Gas quality regulations. 199 Gas mte (appliance), 111

measurement of. 193 Gas Safety (Installation and Use)

Regulations 1998. Ill. 112. 318,319.349.352.365

Gas Transmission System. National, 188

GASCARD. 256. 257 Gascoseeker. 506 Gases. 1

comparison of properties. 12 constituents of. 11 families of. 9

molecules in, 2 toxic, 6

Gimlet, 447 Goggles, 458 Graham's law of diffusion. 3 Grinding machine, 475

Hammers, 432, 467 Handling. 155 Hardening metals. 428 Hardness, 407 Health and Safety Executive, 89 Heat. 132 Heat energy. 123

£aleS, 139 Heat exchangers. 328, 337

INDEX

Heat loss from buildings/walls. 342 Heat sensitive materials. 496 Heat tmnsfer ... et! Transfer of heat Heat treatment of metal s, 427 Heating systems

circulating pressure, 183. 184 hydroslatic pressure, 181 water pressure, 183

Henry. 320 Hertz, 287 High explosive limit, 10 Hooke's Law, 148 Hot dipping, 427 Hot wire filaments, 38 Humidity. 137 Hydrogen

atomic structure. 14, IS flame/atmospheric effect, 42

HydroSlatic pressure. 181

Ice. latenl heat of, 136 Ignition, 38 Ignition devices. 391 Ignition system, direct spark. 389 Ignition temperatures, 1I Impedance. 321 Inclined gauge. 177 Incomplete combustion, 34

chilling lhe flame, 36 oxygen starVation. 36 products of. 34

Indexes, meter, 245 cubic feet, 241 cubic metres, 241

521

dia1-type, 247 liquid crystal display (LeO), 250 older types, 242, 247 reading. 241 R5,244

Induction. magnetic. 284 Inductive reactance, 321 Inductor, 319 Inferential meters. 233 Injector, 28, 91 . 92

comparison of characteristics, 93 eccentric, 92 orifice size vital. 93

Institution of Gas Engineers, meter specification. 238

Insulation (electrical), 268 Intennittent pilol systems, 389 Internal gauze. 91 , 99 Inverse square law, 336 Ions, 270 Iron , types of. 410 Ilron unit, 252

Jets, pre-aerated, 104 Joint maker. electric capillary. 459 Joule, 123, 128

Kala thennometer, 497 Kelvin. 132 Kilogram, 125 Kilowatt, 129 Kilowatt-hour, 7.123. 129,

265, 273 Kinetic energy, 122 Kinetic Theory. 3 Kirchhoffs Law, 279

Lacquering. 425 Ladders, 476 Latent heat. 135. 136 Lead,413 Leak detection, 504

catalytic combustion, 505 flame ionisation . 506 lherrna1 conductivity. 505

Levers, 144 Lifting, 155

kinetic. 156. 157 Light emitting diode (LED), 252 Lighting-back, 30, 3 1 Limit of proportionality, 148

522

Lint. composition of. 112 Linting, 106, 112 Liquefied Petroleum Gas

(LPG),43 air systems, 55 boiling points, 49 calorific value, 53 chemical propenies, 44 coefficient of cubical expansion of

liquid. 51 combustion, 47 containers, 52, 54, 58 dew point. 53 distribution, 56, 57 Oammability. limits of, 52 latent heat, 50 odorisation of, 52 physical propenies, 49 pressure standard,

minimum, 199 regulators. 216 relative density, 51 sources, 43 special grades, 46 specific volume, 51 typical properties, 46. 47 vapour pressure, 49 what is? 43

Liquid crystal display (LeD),250

Liquids, 2 Low pressure cut-offs, 352 Lower explosive limit, lO LPG Association, 86 Luminous name, 26

Magnetic flux, 281 Magnetism, 280 Main cock, 349 Mains ignition transfonner. 398 Malleability, 407 Malleable iron, 411 Manufactured gases, 9

properties of, 12 Masonry dril1, 439, 468 Mass, 124 Materials, properties of, 405 Matrix burner. 106 Measurement of appliance gas

rates, 193

INDEX

Measurement of gas. 228 Measuring devices, 486 Mechanical advantage, 152 Mechanical energy. 123 Mechanics, 142 Melting points of metals, 133 Meniscus, 172 Metals, 407 Meter control cock, 349

tools, 466 Meter (electrical), 309 Meter (gas), 231

faults, 263 Index (cubic feet), 194 Index (cubic metres), 194 reading indexes, 241 regulations for, 259 test conditions, 262 test dial, 193, 194 test drum, 193, 194 see also names of gas meler,\'

Metering orifices, 103 Methane. 11

molecular structure, 16 Micronic unit, 252 Millibar, 166 Mirror, 458 Mixing tube, 28. 91 Mixtures, 16, 17 Modification of appliances, 114 Modulation of gas supply. electronic,

388, 390 Modulus of elasticity, 148 Molecules, I. 2, 3, 5, 15 Moment of a force, 142 Multifunctional controls, 383 Multimeter, 308, 460

Naphtha, II Natural draught burners, 90 Natural gas, 9

combustion equations, 17,21 constiruenls, 11, 44 oxygen requirements, 19 pressure standard, minimum, 199 products of combustion, 21, 22 properties, 12

Natural rubber, 48 Neat flame, 26 Neon main tester, 459 'Neoprene'. 418

Neutrons, 14, 15 Newton, 128 Nickel,413 Niting, 348 Nitrogen, 11 Non-aemted flame. 26 Non-ferrous metals, 412 Non-metals. 409. 417 Nonnalising metals, 428 Nucleus, atomic, 14 Nylon, 418

Odour. 6. 52 Ohm, 273 Ohmmeter. 308 Ohm's law. 273 Optical pyrometer, 494 Orifice, flow of gas through, 192 Oxidation, 40 Oxygen, 11

flame/atmospheric effect, 41 requirement of gases. 20. 21

Oxygen depletion systems, 365 opemtion, 366 servicing, 366

Paint brushes, 456 Paints and lacquers, 425

metallic, 427 Parkerising, 426 Pascal (unit), 162 Pascal's appamtus, 166 Peart pass stopper, 464. 465 Percussion lools. 475 Pcrfonnance lesters for

appliances, 500 Phase relationships. current and

voltage. 3 19, 320 Piezo-electric effect. 267 Piezo-electric igniter. 396, 397 Pilot flames. 38, 390

pre-aemted. 104 Pin vices. 464 Pipe cutters, 450 Pipes, gas flow in, 189

diameters, 191 estimating sizes, 195 factors in pressure loss, 190

Pipe vices, 463

INDEX

Pipework, internal installation, 196

Pitot tube. 233 Plaster, 421 Plastics, 417 Platinum. 413 Platinum filamenl. 38 Pliers. 441 Poles fonnula, 192 Polyethylene (PE). 417, 424 Polymer molecules, 418 Polystyrene, 418 POlytetrafluoroethylene

(PTFEJ,418 tape, 48, 418

Polyvinyl chloride (PVC). 417 Ports, 28 Positive displacement meters,

236, 237 Post-aemted burner, 90, 105

wi th retention flame, 33 Post-aemted flames, 26 Potential difference, 27 1 Potential energy. 122 Power, 129 Power factor (alternating

current). 321 Power tools, 471

insulated,472 Pre-aemted burner, 90

bar burner. 91 ring burner components, 90 with retention flame, 33

Pre-aemted flames, 27 flame front. 28. 29 inner cone, 27 outer manUe, 29, 30. 31 reaction zone, 29, 30 tempemtures of, 29, 30 zones of, 29

?re-mix burner, 90, 107, 108 Prepayment meters, 266

quantum, 258, 259 Pressure

absolute, 170 atmospheric, 167 control see ConltOl of pressure effect of altitude, 185 in fluids, 163 loss in pipes, 189 measurement of. 171 recorders. 180 units, comparative. 166, 167

523

524

Pressure regulator. 77, 79 Pressures. lif! and reversion, 33 Primary air, 27. 28. 32 Primary air pon, 90, 94 Propane. 11 , 44,45, 49,51

set! also Commercial propane Propane torch, 451. 452, 469 Propylene, 11 ,44, 45 Protective clothing, 484 Protective multiple earthing, 3 14 Prolons, 14, 15 Pulley systems, 151 Punches, 434 Pyrometers, 129.494

Quantum meter, 255 Quantum system. 255

charger unit. 260 GASCARD. 257, 259 SERVICE CARD, 259, 26 1

R5 Indel(, 244 anti-tamper device, 248 automated reading system. 244 fischer socket, 245 reed switch. 244 security label. 248, 250 telecom socket. 245

Radian, 126 Radiant burners, 109 Radiant heal, 138

flow. 335 Radiant heating appliances, 334. 335 Radiation. 323, 333

environmental . 138 Radiation pyrometer, 494 Radiator. hot water, 34 1 Rat-tail flames, 105 Reaction zones. 29, 30 Rectifiers, 305 Reduction, chemical, 40 Refrigerator

temperatures. 133 thermostat, 378, 379

RegulalOrs aux:illary diaphragm, 207 'chattering', 227 commissioning. 225 compensation requirement. 206 components, 220

INDEX

construction, 209, 210, 211 fauUs, 226 high-to-Iow pressure regulators,

211,212 'hunting', 227 impulse pipe, 208 installation, 216 loading, 209 LPG, 60, 67, 68, 78, 80, 212, 220 meter, 216, 217 safety, 80 service, 216 servicing, 225 valve, 203

Relative density, 7, 51 Relay. electrical, 302 Relay valves. 354

fail safe, 356 Residual current circuit breaker. 316 Residual current device adaplOr, 460 Resistance. 273 Resistor, 296

colour coding, 298 letter/number coding, 300

Retention flames. 33, 34 Retention pons. 91.103.104 Reversion pressure, 33 Rheostat, 296 Right-hand rule (magnetic flux),

284,285 Ring main circuit. 291, 292 Ring main tester. 459 Roofs. working on, 482 Room-sealed appliances, 113 Room temperatures, 133. 138 Root mean square voltage and

current. 287 Roots type meter. 233-4 Rotary displacement meter, 233-4

Safety consideration and emergency action. 83, 84, 85, 86

Safety relief valve. 49 Safety torch. 455 Saturated air, 137 Saws, mechanical. 475 Saws. metal. 436 Saws. wood, 435 Scaffolding. 483 Screwdrivers, 446, 468 Screwing machines, 475

-

Secondary air. 27 Seger cones. 4% Sensible heat, 135, 136 Service regulator. 216 Sherardising.427 Sine wave. 286

INDEX

Single column pressure gauge. 176 Slings, 154 Smartcard, 266 Socket forming tool. 461 Solar power. 123 Solder. 414

lead-free, 415. 416 Soldering irons. 459 Solenoid. 282. 294. 30 1 Solenoid valves. 381 Solids, I Solvents, 429 Soot. 35 Spanners. 443 Spark ignition. 39. 40. 396 Specific gravity. 7 Specific heat. 133 Specific heat capacity. 133 Specific volume. 51 Speed, 125 Spiril level, 454 Stainless steel. 415-16 Standing pressure. 189 Statics. 142 Steel. 41 1 Steel rules, 455 Stefan-Boltzmann Law. 336 Stefan's constant. 336 Stocks and dies, 463 SlOpper glove, plastic. 464 Strain. 146 Stratification, heat. 330-2 Stress. 146, 405. 406

in beams, 149 Substitute natuml gas (SNG). 12

characteristics, 12 pressure standard. minimum. 100

Substitute natural gas plant, 12. 13 Suction pyrometers. 494 Symbols. chemical. 5

Tank cutters. 461. 462 Tanks (LPG). 73. 74. 75. 76. 77

contents gauge. 76

filling connection, 76 outlet (service) connection, 76 pressure gauge, 76 pressure relief valve. 75 temperature gauge. 76

Tap. gas, 347-9 faults. 355-6

Taps, thread cutting. 448. 476 Target burner, 106 Tempemture. 129

ambient, 332 measurement of. 129, 130, 139 scales of, 130. 131. 132

Tempering. 428

525

colours and temperatures, 429 Temporary continuity bond, 318, 453 Testing tee. 466-7 Thenn. 7, 122, 123 Thennal backflow prevention device

(TIB),368 operation. 368 servicing, 368-9

1bcnnal conductance, 326 Thennal conductivity, 324, 326 Thennal cut-offs. 352 Thermal efficiency. 141 Thermal transminance

coefficient. 343 Thennistor. 297, 492 Thennocouple. principle of. 361. 362 Thennometer, 129, 130

bimetallic, 489 gas expansion. 489 kata, 497 liquid in glass. 487 liquid in steel. 489 JX>Cket. 462 pyrometers. 494 resistance. 490-1 vapour pressure. 489

Thennoplastics. 417- 18 Thcnnoselting plastics. 417 Thennostat. 372-9

bimetal rod-type. 373 bimetal strip type. 376--7 cooker oven. 374 liquid expansion. 377-9 refrigemtor, 378 vapour pressure. 379

Thorpc rotary meter. 235-6 Throat restrictor. 91, 95-6

526

Timber, 41S-19 Tin. 415 Tinsnips, 454 Tools. use, care and maintenance.

467-70 Tool roll s and bags. 460-1 Torch. 451-5 Toxic gases, 6 Trade and Industry, Department

of. 7 Transfer of heat, 323-46 Transducer. 250 Transfomlcr. 289, 293-5 Trowel. 454 Tumpin.456

'U' gauge, 174-5.453 U6 meter. 240, 242, 248, 251. 254.

255. 256 prepayment, 257 with £1 coinpialc, 256 prepayment token meter, 257

Ultrasonic UE6 meter, 252 advamages of. 252 construction of. 25 1 index, 253 liquid crystal display (LeO), 250 measurement. principle of. 250 U6-E6 comparison. 252 optical communication

pon, 252 'U' values for building components,

343,344 Unit conslnlc(ion meter, 238, 239.

240.241,243

Vacuum cleaner. 458. 475 Value added tax. 266 Valve, gas, 347-8 Valves

ball,351 bulterily. 349, 351, 381 electro-hydraulic, 380. 382~3 gate, 350 motorised. 38 1. 382 power operated, 379-83 relay, 354-5 solenoid. 381 zoning, 381

Vane anemometer, 498 Vapour, cxplosive, 486

INDEX

Vapour offtake, 69, 70 Vapourisation, latent heat of. 135 Vapouriscr, 78 Velocity, 125-6 Velocity ratio, 154 Velometcr,499 Ventilation heat loss, 342-3 Venturi, 92. 96-8

energy changes within, 98 flow of gas through, 193

Viscosiry of LPG, 56 Vices

pin, 464. 465 pipe, 453-4, 465

Vitreous enamcl, 426 Volt. 271 Voltage

alternating current, 285-7 out-of-phase, 3 19-2 1

Voltmeter, 307 Volume. variation wi th pressure, 229

Water flow gauge, 462 Water heater burner, multipoint, 119 Water pipework bye laws, 413, 415 Watcr pressure

circulating. 182, 183 heads, 182 hydrostatics, 181-2

Water temperutures, 133 Water vapour, 7, 137, 139

flame/atmospheric effect, 41 Watt. 129.272 Wavelength or radiant heat,

335-8 Weight. 124-5 Wet meter. 253 Wheatstone bridge. 490 Wire brushes, 456 Wire strippers. 458 Wiring regulations. 313, 318 Wobbe number (index). 8 Work. 128 Working pressure, 189-90 Wrenches. 442-3. 468 Wrought iron, 411

Young's modulus, 148

Zinc, 58, 270, 414