Gas Installation Technology

Roy Treloar has been involved with the mechanical service industry since leaving school in 1973, becoming a full time lecturer, teaching plumbing in 1985. He is currently the curriculum development manager for the Professional Training Centre at Colchester Institute where he is responsible for various plumbing, heating, gas and electrical training and assessment programmes. Roy is author of several books, including two highly successful textbooks, Plumbing, and Plumbing Encyclopaedia, both published by Wiley-Blackwell.

Introduction xi Acknowledgements xii Abbreviations and Acronyms xv Part 1 The Gas Industry 1 The Gas Industry 2 Nationally Accredited Certification Scheme for Individual Gas Fitting Operatives (ACS) 4 Required ACS Assessments and Flowcharts 6 Legislation Affecting the Gas Installer 1 10 Legislation Affecting the Gas Installer 2 12 Industry Documents and British Standards 14 Gas Safety (Installation and Use) Regulations 16 Part 2 Gas Utilisation 19 Gas: Its Origin 20 Characteristics and Properties of Gases 22 Liquefied Petroleum Gas (LPG) 26 The Combustion Process 28 Air Requirements for Combustion 30 Products of Combustion 32 The Gas Flame 34 Flame Pattern and Characteristics 36 Atmospheric Burners 38 Pre-mix Burners 40 Gas Pressure and Flow 42 Gas Pressure Readings 44 Quick Reference Guide to Taking Pressures 46 Estimating a Suitable Pipe Size 48 Domestic Natural Gas Pipe Sizing 50 Commercial Pipe Sizing 52 Determining Existing Losses Due to Pipe Size 54 Gas Rates and Heat Input 56 Quick Reference Tables: Gas Rate/Heat Input 58 The Physical Laws Relating to Gas 60 Measurement of Gas 1 62 Measurement of Gas 2 64 Part 3 Gas Controls 69 Quarter Turn Gas Control Valves 70 Screw Down Gas Control Valves 72 Spring Loaded Gas Control Valves 74 Electrically Operated Gas Control Valves 76 Heat Operated Gas Control Valves 78 Pressure Operated Controls Valves 80 Low and High Pressure Cut-off Devices 82 Pressure Regulators 84 LPG Regulators 1 88 LPG Regulators 2 90 Flame Supervision Devices 92 Testing Flame Supervision Devices 98 Thermostatic Control 100 Multi-functional Gas Valve 1 102 Multi-functional Gas Valve 2 104 Ignition Devices 106 Vitiation Sensing Devices 108 Pressure and Flow Proving Devices 110 Part 4 Installation Practices 113 Polyethylene Pipe Jointing 114 Copper Pipe Jointing 116 Mild Steel Pipe Jointing 118 Semi-rigid and Flexible Pipe Connections 120 Gas Service Pipework 122 Connections to High Rise Buildings 126 Gas Meter Installations 128 Commercial Gas Installations 132 Internal Installation Pipework 134 Pipework Laid in Floors 136 Pipework in Walls 138 Pipework Support and Allowance for Movement 140 Timber Framed Dwellings 142 LPG Supply 144 LPG Cylinder Installation 146 Storage and Transportation of LPG Cylinders 148 LPG Bulk Tank Installation 150 Gas Supplies from a Bulk Tank Installation 152 LPG Vapour Take-off Capacity 154 Pipe Sizing LPG Installations 156 Part 5 Tightness Testing 159 Tightness Testing and Purging 160 Testing Equipment 162 Tightness Testing with Air (Domestic) 164 Tightness Testing Natural Gas Installations with System Volumes 0.035 m3 (i.e. Domestic) 166 Purging Natural Gas Systems with a Volume 0.035 m3 (i.e. Domestic) 170 Tightness Testing and Purging with LPG (Domestic) 172 Strength Testing for Commercial Pipework 176 Commercial Tightness Testing 180 Direct Purging Commercial Pipework 186 Commercial Purging Procedure 192 Indirect Purging Using Nitrogen (N2) 194 Part 6 Flues and Chimneys 197 Flue/Chimney Classification 198 Chimney/Flue Material and Specification 200 Natural Draught Open Flue Systems 202 Installation of an Open Flue Chimney 204 Minimum Open Flue Heights 1 206 Minimum Open Flue Heights 2 208 Open Flue Terminal Design and Location 210 Condensation within Open Flue Systems 212 Brick Chimneys 214 Flexible Stainless Steel Flue Liners 216 Pre-cast Flue Blocks 218 Pipes Used for Chimneys 220 Fan Draught Open Flue Chimney Systems 222 Shared Open Flue Chimney Systems 224 Checking and Testing Open Flue Systems 226 Room Sealed Flue Chimneys 228 Fan Assisted Room Sealed Flue Applian