Andrew S. Burcham is an Engineering Technician Member of The Institution of Gas Engineers. He has over 40 years of experience in the gas industry, starting as an apprentice Gas Service Engineer with British Gas in 1981. He worked for British Gas for 25 years, later becoming an assessor and trainer. In 2006, he left British Gas and worked as a self-employed heating engineer while also assessing ACS programs at colleges. Since 2014, Andrew has been the ACS Centre Manager at Colchester Institute, delivering training and assessment programs for plumbing and heating engineers. His depth of knowledge and hands-on experience make him an invaluable resource.

Stephen J. Denney is a highly respected tutor and assessor in the gas industry, bringing over 30 years of invaluable experience. After graduating as an award-winning plumbing student in 1991, he established a successful business in mechanical services. In 2014, Stephen became a full-time lecturer and assessor and currently holds a pivotal role at Colchester Institute's Gas and Utilities Department. In this position, he oversees quality assurance and develops industry courses, equipping professionals with essential skills for success in the gas industry. His extensive practical experience, combined with his role as an assessor, enables him to provide valuable insights and real-world perspectives to professionals in the gas and utilities sector.

Introduction xi

Acknowledgements xiii

1 The Gas Industry 1

The Gas Industry 1

Nationally Accredited Certification Scheme for Individual Gas Fitting Operatives (ACS) 4

Required ACS Assessments and Flowcharts 9

Legislation Affecting Gas Operatives 10

Specific Legislation Affecting Gas Operatives 15

Industry Documents and British Standards 17

Gas Safety (Installation and Use) Regulations 21

The Future of Gas 24

2 Gas Utilisation 27

Gas: Its Origin 27

Characteristics and Properties of Gases 29

Liquefied Petroleum Gas (LPG) 33

The Combustion Process 34

Air Requirements for Combustion 37

Products of Combustion 39

The Gas Flame 41

Flame Pattern and Characteristics 44

Atmospheric Burners 46

Pre-mix Burners 48

Gas Pressure and Flow 50

Gas Pressure Readings 52

Quick Reference Guide to Taking Pressures 54

Estimating a Suitable Pipe Size 56

Domestic Natural Gas Pipe Sizing 58

Domestic LPG Pipe Sizing 62

Commercial Natural Gas Pipe Sizing 67

Gas Rates and Heat Input 69

Electronic and Smart Meters 72

Quick Reference Tables: Gas Rate/Heat Input 73

The Physical Laws Relating to Gas 76

Measurement of Gas 78

3 Gas Controls 87

Quarter Turn Gas Control Valves 87

Screw Down Gas Control Valves 90

Valve Application 93

Spring-loaded Gas Control Valves 94

Electrically Operated Gas Control Valves 96

Heat-operated Gas Control Valves 98

Pressure-operated Controls Valves 100

Low- and High-pressure Cut-off Devices 102

Pressure Regulators 105

LPG Regulators 108

Flame Supervision Devices 113

Testing Flame Supervision Devices 120

Thermostatic Control 120

Multi-functional Gas Valve 122

Air/Gas Ratio Valve 125

Ignition Devices 127

Vitiation-sensing Devices 129

Pressure and Flow Proving Devices 132

4 Installation Practices 135

Polyethylene Pipe Jointing 135

Copper Pipe Jointing 138

Mild Steel Pipe Jointing 141

Semi-rigid and Flexible Pipe Connections 143

Gas Service and Installation Pipework 145

Connections to High-rise Buildings 150

Gas Meter Installations 153

Commercial Gas Installations 158

Internal Installation Pipework 160

Pipework Laid in Floors 162

Pipework in Walls 165

Pipework Support and Allowance for Movement 168

Timber-framed Dwellings 170

LPG Supply 173

LPG Cylinder Installation 174

Storage and Transportation of LPG Cylinders 176

LPG Bulk Tank Installation 178

Gas Supplies from a Bulk Tank Installation 181

LPG Cylinder Sizing 184

5 Testing and Purging 187

Testing and Purging 187

Tightness Testing With Air (Domestic) 193

Tightness Testing Natural Gas Installations (Domestic) 194

Tightness Testing LPG Installations (Domestic) 199

Purging Domestic Gas Installations 204

Commercial Strength and Tightness Testing (TPCP1A) 209

Commercial Strength and Tightness Testing (TPCP1) 217

Direct Purging Commercial Pipework 230

Indirect Purging Using Nitrogen (N2) 239

6 Flues and Chimneys 243

Flue/Chimney Classification 243

Chimney/Flue Material and Specification 244

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