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AS/NZS 4645.1:2018


Gas distribution networks, Part 1: Network management

Specifies the requirements for safe, reliable and affordable management throughout the lifecycle of a gas distribution network operating at less than or equal to 1050 kPa. Requirements for pipelines with a MAOP greater than 1050 kPa, which is allowed in some jurisdictions, are included in an Appendix.
Published: 28/02/2018
Pages: 132
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Table of contents
Cited references
Content history
Table of contents
About this publication
1 Scope and general
1.1 Scope
1.2 Exclusions
1.3 Referenced documents
1.4 Notation
1.5 Definitions
2 Network safety
2.1 Basis of section
2.2 General
2.3 Formal safety assessment (FSA)
2.3.1 General
2.3.2 Acceptable level of risk
2.3.3 Hazard identification
2.3.4 Determination of threats
2.3.5 Assessment of risks
2.3.6 Control of risk
2.3.7 Review of overall FSA
2.3.8 Situation-specific FSA
2.3.9 Validation
2.4 Safety and operating plan (SAOP)
2.4.1 General
2.4.2 Elements of SAOP
2.5 Competency of personnel
2.6 Records management
2.7 Means of conformance
3 Planning
3.1 Basis of section
3.2 General
3.3 Functional requirements
3.3.1 General
3.3.2 Gas specification
3.4 Ongoing network planning
3.5 Uprating of MAOP
3.5.1 General
3.5.2 Maximum allowable operating pressure
3.5.3 Planning
3.5.4 Investigation
3.5.5 Staged increase of pressure
3.5.6 Records
4 Network design
4.1 Basis of section
4.2 General
4.3 Design process
4.3.1 Design inputs
4.3.2 Design process controls
4.3.3 Design review
4.3.4 Design outputs
4.4 Control of design and development changes
4.5 Materials and equipment
4.5.1 General
4.5.2 Materials and equipment selection process
4.5.3 Materials identification and traceability
4.6 Reclaimed materials and reclaimed components
4.7 Route/site assessment
4.7.1 General
4.7.2 Energy release rate
4.8 Maximum allowable operating pressure (MAOP)
4.9 Network pressure control
4.9.1 General
4.9.2 Over-pressure protection
4.9.3 Types of over-pressure safety devices
4.9.4 Location of network pressure control equipment
4.10 Mains and services
4.10.1 General
4.10.2 Mains and services under buildings
4.10.3 Design of wall thickness
4.10.4 Design of depth of cover and underground protection
4.10.5 Exposed mains and services
4.10.6 Design for natural hazards
4.10.7 Alignment
4.10.8 Joining of mains and services
4.10.9 Upstands
4.10.10 Isolation of services
4.10.11 Internal services
4.11 Sectional isolation
4.11.1 General
4.11.2 Isolation valve requirements
4.12 Consumer meter assemblies
4.12.1 General
4.12.2 Residential premises
4.12.3 Industrial and commercial consumer meter assembly
4.13 Associated infrastructure
4.14 Additional requirements for LP gas networks
5 Construction, testing and commissioning
5.1 Basis of section
5.2 General
5.3 Construction, testing and commissioning processes
5.4 Installation
5.4.1 Pipe installation
5.4.2 Network pressure control stations
5.4.3 Consumer meter assemblies
5.4.4 Ancillary equipment
5.5 Testing
5.5.1 General
5.5.2 Mains and services
5.5.3 Network pressure control stations General Integrity tests Functional tests Requirements
5.5.4 Consumer meters assemblies
5.5.5 Ancillary equipment
5.6 Commissioning
5.6.1 General
5.6.2 Mains and services
5.6.3 Network pressure control stations
5.6.4 Consumer meter assemblies
5.6.5 Meters
5.6.6 Ancillary equipment
5.7 Purging and flaring
6 Operations
6.1 Basis of section
6.2 Pre-operating requirements
6.2.1 Completion of preparations
6.2.2 Pre-operation check: Gas detection
6.3 Network pressure management
6.3.1 General
6.3.2 Minimum operating pressure
6.3.3 Over-pressure protection
6.3.4 Prevention of unauthorized operation
6.4 Gas specification and characteristics
6.4.1 General
6.4.2 Gas detection
6.4.3 Gas supplied in containers
6.5 Leakage management
6.5.1 General
6.5.2 Public reporting of leaks
6.5.3 Leakage surveys
6.5.4 Leakage reports, review and analysis
6.6 Third party activities
7 Maintenance and repair
7.1 Basis of section
7.2 Maintenance planning
7.3 Mains and services
7.3.1 General
7.3.2 Repairs
7.3.3 Repair following squeeze-off of plastic mains
7.3.4 Purging mains and services
7.4 Network pressure control stations
7.5 Consumer meter assemblies
7.6 Ancillary equipment
7.7 Venting and flaring procedures
8 Decommissioning and abandonment
8.1 Basis of section
8.2 General
9 Emergency response planning and incident investigation
9.1 General
9.2 Emergency response planning
9.2.1 General
9.2.2 Emergency response plans
9.2.3 Review and update of documentation
9.3 Significant incidents and significant near misses
10 Performance monitoring
10.1 General
10.2 Performance monitoring plan
10.3 Auditing
10.4 Performance reports
Appendix A
A1 Purpose, scope and application
A1.1 Purpose
A1.2 Scope
A1.3 Application
A1.4 Exclusions
A2 Network design
A2.1 Mains and services
A2.2 Services under buildings
A2.3 Isolation valves
A2.4 Energy release rates
A3 Construction, welding and testing
A3.1 Construction, welding and testing
A3.2 Clearances
A4 Maintenance and repair
A4.1 Third party activities
Appendix B
B1 General
B2 Consequence analysis
B3 Likelihood analysis
B4 Risk ranking
B5 Risk treatment
B5.1 General
Appendix C
Appendix D
D1 General
D2 Classification
D2.1 Class 1
D2.2 Class 2
D2.3 Class 3
D3 Leak surveying and classification of leaks—LP gas
D3.1 General
D3.2 Mapping of bar hole locations
D3.2.1 Bar hole locations
D3.2.2 Leak classification of a LP Gas distribution network
D3.2.3 Utility pits or underground utility chambers
Appendix E
E1 Scope of information
E2 Types of information
Appendix F
F1 General
F2 Material evaluation and acceptance
F3 Material and component selection
F3.1 General
F3.2 Materials comprising active metals
F3.3 Materials in associations resulting in bi-metallic corrosion
F3.4 Designs and configurations leading to crevice corrosion
F3.5 Materials in plastics
F3.6 Materials adversely affected by solvents, plasticizers and other chemicals
F3.7 Odorant and its interaction with materials
F3.8 Materials comprising passive alloys
F3.9 Materials that are free machining alloys
F3.10 Materials that are dezincification resistant alloys
F3.11 Designs and configurations leading to stress concentrators
F3.12 Valves and regulators
F3.13 Mechanical fittings
Appendix G
G1 General
G2 Requirements for residential buildings
G3 Location of internal services
G3.1 Prohibited locations
G3.2 Piping not to be subject to physical damage
G3.3 Separation from above-ground low and extra low voltage electrical equipment
G3.4 Piping not to support an electrical conductor
G3.5 Piping not to be exposed to liquid discharge
G3.6 Above-ground piping not to touch the ground
G3.7 Piping in a concealed location
G3.8 Piping passing through a building’s exterior wall
G3.9 Piping passing through floors and internal walls
G3.10 Piping in the ground beneath a building
G3.11 Piping embedded in concrete
G3.12 Piping in wooden joists
G3.13 Piping in wooden plates and studs
G3.14 Piping in steel framed buildings
G3.15 Protection of multilayer piping
G3.16 Ventilation of concealed piping
Appendix H
H1 General
H2 Signage
H2.1 Sign spacing
H2.2 Sign design
Appendix I
I1 General
I2 Maximum operating pressure
I3 Prohibited locations for consumer meter assemblies
I4 Location of consumer meter assemblies—General
I5 Siting a consumer meter assembly on a property
I6 Consumer meters assemblies in enclosures
I7 Consumer meters assemblies in buildings
I7.1 General
I7.2 Regulators
I7.3 Meter room—Design general
I7.4 Meter room ventilation
I7.4.1 General
I7.4.2 Natural ventilation to outside
I7.4.3 Natural ventilation via adjacent room
I7.4.4 Mechanical ventilation
I7.4.5 Combination of natural and mechanical ventilation
I7.4.6 Location of openings
I7.4.7 Multiple meters
I8 Design of vent lines
I8.1 General
I8.2 Vent line terminating outside a building
I8.3 Size of vent line for a relief device
I8.4 Size of vent line for a vented safety shut-off system
I8.5 Size of a common vent line
I8.6 Vent terminal location
I9 Breather ports
I9.1 General
I9.2 Discharge from breather ports
I9.3 Restriction of breather ports
I10 Precautions against low temperature operation
I11 Multiple consumer meter assemblies
I12 Over-pressure protection
I13 Types of over-pressure safety devices
I14 Prevention of unauthorized operation
Appendix J
J1 Post-construction inspection
J2 Planning for commissioning
J3 On-site commissioning
J4 Post-commissioning issues
Appendix K
K1 General
K2 System reliability
K3 System damage
K4 Product control
K5 System performance
K6 Contingency management and emergency response
K7 Worker competency
Appendix L
Appendix M
Appendix N
Cited references in this standard
Pipe threads where pressure-tight joints are made on the threads, Part 1: Dimensions, tolerances and designation
Buried, high-impact poly(vinyl chloride) (PVC-HI) piping systems for the supply of gaseous fuels, Part 1: Pipes for a maximum operating pressure of 1 bar (100 kPa) (ISO 6993-1:2006, MOD)
Buried, high-impact poly(vinyl chloride) (PVC-HI) piping systems for the supply of gaseous fuels, Part 3: Fittings and saddles for a maximum operating pressure of 1 bar (100 kPa)
PVC pipes and fittings for pressure applications
AS/NZS 2537.5
Mechanical jointing fittings for use with crosslinked polyethylene (PE-X) for pressure applications, Part 5: Plastics pipes and fittings—Crosslinked polyethylene (PE-X) pipe systems for the conveyance of gaseous fuels—Metric series—Specifications—Fitting
Content history
DR AS/NZS 4645.1:2017