1 - AS 4645-2005 GAS DISTRIBUTION NETWORK MANAGEMENT - GAS DISTRIBUTION NETWORK MANAGEMENT
4 - PREFACE
6 - CONTENTS
8 - SECTION 1 SCOPE AND GENERAL
8 - 1.1 SCOPE
8 - 1.2 EXCLUSIONS
10 - 1.3 RETROSPECTIVE APPLICATION OF STANDARD
11 - 1.4 REFERENCED DOCUMENTS
11 - 1.5 PRESSURE CLASSIFICATIONS
11 - 1.6 DEFINITIONS
11 - 1.6.1 Actual thickness
11 - 1.6.2 Approved
11 - 1.6.3 Authority
11 - 1.6.4 Casing
11 - 1.6.5 Consumer piping
11 - 1.6.6 Fuel gas
11 - 1.6.7 Inspector
11 - 1.6.8 Internal design pressure
12 - 1.6.9 Liquefied petroleum gas/LP Gas
12 - 1.6.10 Main
12 - 1.6.11 Maximum allowable operating pressure (MAOP)
12 - 1.6.12 Monitoring regulator
12 - 1.6.13 Network
12 - 1.6.14 Network operator
12 - 1.6.15 Nominal thickness
12 - 1.6.16 Odorization
12 - 1.6.17 Pressure
12 - 1.6.18 Pressure design thickness
12 - 1.6.19 Pressure-limiting station
12 - 1.6.20 Pressure-regulating station
13 - 1.6.21 Pressure-relief station
13 - 1.6.22 Regulator
13 - 1.6.23 Required thickness
13 - 1.6.24 Service
13 - 1.6.25 Service regulator
13 - 1.6.26 Shall
13 - 1.6.27 Should
13 - 1.6.28 Specified minimum yield stress (SMYS)
13 - 1.6.29 Statutory authority
13 - 1.6.30 Thickness
14 - SECTION 2 NETWORK SAFETY
14 - 2.1 GENERAL
14 - 2.2 SAFETY AND OPERATING PLAN
14 - 2.3 SYSTEM MANAGEMENT
14 - 2.4 COMPETENCIES
14 - 2.5 RECORDS
16 - SECTION 3 NETWORK PLANNING
16 - 3.1 GENERAL
16 - 3.2 FUNCTIONAL REQUIREMENTS
16 - 3.3 BASIS OF DESIGN
17 - SECTION 4 NETWORK DESIGN
17 - 4.1 GENERAL
17 - 4.2 DESIGN PRESSURES
17 - 4.3 NETWORK DESIGN DETAILS
17 - 4.3.1 Safety assessment of route
17 - 4.3.2 Materials and components
18 - 4.3.3 Pressure control
19 - 4.3.4 Meter/regulator specification
19 - 4.3.5 Pipe wall design thickness
20 - 4.3.6 Design of depth of cover and underground protection
20 - 4.3.7 Pipe identification and warning system, and contents identification
20 - 4.3.8 Design for natural hazards, and crossings
20 - 4.3.9 Additional requirements for LP Gas systems
21 - 4.4 DESIGN ELEMENTS OF MAINS AND SERVICES, AND ASSOCIATED PIPEWORK
21 - 4.4.1 Mains
21 - 4.4.2 General design of internal service lines and risers
22 - 4.4.3 Associated pipework
22 - 4.4.4 Corrosion mitigation of buried steel pipe
24 - SECTION 5 CONSTRUCTING, TESTING, COMMISSIONING
24 - 5.1 GENERAL AND DOCUMENTATION
24 - 5.2 SEPARATION FROM OTHER UNDERGROUND STRUCTURES
24 - 5.3 COATING FOR BURIED METAL PIPE
24 - 5.4 PIPE INSTALLATION METHODS
24 - 5.4.1 General
24 - 5.4.2 Trenched installation
25 - 5.4.3 Trenchless installation
25 - 5.4.4 Insertion
25 - 5.5 TESTING
25 - 5.5.1 Mains and Services
26 - 5.5.2 Over-pressure protection
26 - 5.6 COMMISSIONING OF GAS MAINS
26 - 5.6.1 General
26 - 5.6.2 Planning
27 - SECTION 6 OPERATING AND MONITORING
27 - 6.1 PRE-OPERATING REQUIREMENTS
27 - 6.1.1 Completion of preparations
27 - 6.1.2 Plans and procedures
27 - 6.1.3 Responsible personnel
27 - 6.1.4 Hazards, and safe practices
28 - 6.1.5 Venting procedures
28 - 6.2 OPERATING AND MONITORING
28 - 6.2.1 Maximum allowable operating pressure
28 - 6.2.2 Damaged pipe or component
28 - 6.2.3 Odour
29 - 6.2.4 Public reporting of leaks
29 - 6.2.5 Leakage surveys
29 - 6.2.6 Response to leak reports and surveys
29 - 6.2.7 Network pressure and flow control monitoring
29 - 6.2.8 Route monitoring
29 - 6.2.9 Locality monitoring, and asset location information
30 - 6.2.10 Valve operability monitoring
30 - 6.2.11 Monitoring of system performance, growth, pressures, flows and fringe points
30 - 6.2.12 Inspection of structures housing gas equipment
30 - 6.2.13 Special inspections
30 - 6.3 REVIEWS, REPORTS AND ANALYSIS
30 - 6.3.1 Leakage reports, review and analysis
30 - 6.3.2 Corrosion protection review
31 - 6.3.3 Incident reporting, review and analysis
31 - 6.3.4 Risk reviews
32 - SECTION 7 MAINTAINING AND REPAIRING
32 - 7.1 GENERAL
32 - 7.2 REPAIR OF COATING OF BURIED METAL PIPE
32 - 7.3 MAINTENANCE AND REPAIR OF COATING ON ABOVE-GROUND PIPEWORK
32 - 7.4 STEEL-CASED CROSSINGS
32 - 7.5 WORK ON GAS MAINS
32 - 7.5.1 General
32 - 7.5.2 Purging mains and services
34 - SECTION 8 MODIFYING
34 - 8.1 DESIGN OF MODIFICATIONS
34 - 8.2 CONSTRUCTION, TESTING AND COMMISSIONING OF MODIFICATIONS
35 - SECTION 9 DECOMMISSIONING
35 - 9.1 MAKING SAFE
36 - APPENDIX A - LIFE-CYCLE OF NETWORK
36 - A1 PLANNING
36 - A2 DESIGN
36 - A3 CONSTRUCT, TEST AND COMMISSION
36 - A4 OPERATE, MONITOR, MAINTAIN, REPAIR AND MODIFY
36 - A5 DECOMMISSION
37 - APPENDIX B - REFERENCED DOCUMENTS
38 - APPENDIX C - MATERIALS, COMPONENTS, AND DESIGN CONDITIONS GUIDELINES
38 - C1 GENERAL
38 - C2 MATTERS THAT SHOULD BE INCLUDED FOR CONSIDERATION
38 - C2.1 Materials comprising active metals
38 - C2.2 Materials in associations resulting in bi-metallic corrosion
38 - C2.3 Designs and configurations leading to crevice corrosion
38 - C2.4 Components in plastics
38 - C2.5 Materials adversely affected by solvents
38 - C2.6 Materials comprising passive alloys
38 - C2.7 Materials that are free machining alloys
38 - C2.8 Materials that are dezincification resistant alloys
39 - C2.9 Designs and configurations leading to stress concentrators
40 - APPENDIX D - CONTROL OF GAS PRESSURE
40 - D1 GENERAL
40 - D2 MAXIMUM ALLOWABLE OPERATING PRESSURE OF SYSTEM
40 - D3 PROTECTION FROM EXCEEDING MAOP
40 - D4 REGULATING CAPACITY
40 - D5 LOCATION OF PRESSURE CONTROL EQUIPMENT
41 - D6 DESIGN OF REGULATING DEVICES
41 - D7 DESIGN OF VENTS
41 - D8 NOISE CONTROL
42 - D9 PRECAUTIONS AGAINST FREEZING
42 - D10 PROTECTION OF REGULATORS FROM SOLID MATTER IN GAS
42 - D11 INTEGRAL OVER°PRESSURE SAFETY DEVICES
42 - D12 TYPES OF OVER-PRESSURE SAFETY DEVICE
43 - D13 PREVENTION OF UNAUTHORIZED OPERATION
43 - D14 SERVICE REGULATOR INSTALLATIONS
43 - D15 SERVICE REGULATORS
44 - D16 FAILURE OF EQUIPMENT
45 - APPENDIX E - MARKERS AND MARKING
46 - APPENDIX F - EMERGENCY PLANS
46 - F1 GENERAL
48 - APPENDIX G - CLASSIFICATION OF LEAKS
48 - G1 GENERAL
48 - G2 CLASSIFICATION
48 - G2.1 Class 1
48 - G2.2 Class 2
48 - G2.3 Class 3
50 - APPENDIX H - PIPE IDENTIFYING, LOCATING AND WARNING SYSTEM ELEMENTS