AS 1697-2005

1 - AS 1697-2005 INSTALLATION AND MAINTENANCE OF STEEL PIPE SYSTEMS FOR GAS
4 - PREFACE
5 - CONTENTS
7 - SECTION 1 SCOPE AND GENERAL
7 - 1.1 SCOPE
7 - 1.2 EXCLUSIONS
8 - 1.3 RETROSPECTIVE APPLICATION
8 - 1.4 REFERENCED DOCUMENTS
8 - 1.5 RECORDS
8 - 1.6 DEFINITIONS
8 - 1.6.1 Actual thickness
8 - 1.6.2 Approved
8 - 1.6.3 Authority
8 - 1.6.4 Casing
9 - 1.6.5 Consumer piping
9 - 1.6.6 Fuel gas
9 - 1.6.7 Inspector
9 - 1.6.8 Internal design pressure
9 - 1.6.9 Liquefied petroleum gas/LP Gas
9 - 1.6.10 Main
9 - 1.6.11 Maximum allowable operating pressure (MAOP)
9 - 1.6.12 Monitoring regulator
9 - 1.6.13 Network
9 - 1.6.14 Network operator
9 - 1.6.15 Nominal thickness
9 - 1.6.16 Odorization
9 - 1.6.17 Pressure
10 - 1.6.18 Pressure design thickness
10 - 1.6.19 Pressure-limiting station
10 - 1.6.20 Pressure-regulating station
10 - 1.6.21 Pressure-relief station
10 - 1.6.22 Regulator
10 - 1.6.23 Required thickness
10 - 1.6.24 Service
10 - 1.6.25 Service regulator
10 - 1.6.26 Shall
10 - 1.6.27 Should
10 - 1.6.28 Specified minimum yield stress (SMYS)
10 - 1.6.29 Statutory authority
10 - 1.6.30 Thickness
10 - 1.7 PRESSURE CLASSIFICATIONS
12 - SECTION 2 MATERIALS AND COMPONENTS
12 - 2.1 NEW MATERIALS AND NEW COMPONENTS
12 - 2.2 RECLAIMED MATERIALS AND RECLAIMED COMPONENTS
12 - 2.3 IDENTIFICATION
15 - 2.4 PIPE THREADS, THREADED PIPE FITTINGS, FLANGED PIPE JOINTS AND WELDED PIPE JOINTS
15 - 2.5 VALVES, REGULATORS, FITTINGS AND ACCESSORIES
15 - 2.5.1 General
15 - 2.5.2 Flanges and flanged fittings
15 - 2.5.3 Gaskets and ring joints
15 - 2.5.4 Valves and regulators
17 - SECTION 3 DESIGN
17 - 3.1 GENERAL
17 - 3.2 MAXIMUM ALLOWABLE OPERATING PRESSURE (MAOP)
17 - 3.3 MAXIMUM ALLOWABLE HOOP STRESS
17 - 3.4 WALL THICKNESS
17 - 3.4.1 Steel casing
17 - 3.4.2 Pipe
18 - 3.5 CORROSION MITIGATION
18 - 3.5.1 General
19 - 3.5.2 Insulating joints
19 - 3.6 SUPPORTS
19 - 3.6.1 Anchoring
19 - 3.6.2 Flexibility
19 - 3.6.3 Vibration
19 - 3.6.4 Material for supports
19 - 3.6.5 Forces on pipe joints
19 - 3.6.6 Attachment of supports or anchors
19 - 3.6.7 Interference
19 - 3.6.8 Insulation
19 - 3.7 BENDS, ELBOWS AND MITRES
21 - 3.8 EXPANSION AND FLEXIBILITY
22 - SECTION 4 WELDING
22 - 4.1 GENERAL
22 - 4.2 PREHEAT AND POST-WELD HEAT TREATMENT
22 - 4.3 WELDING POSITIONS
22 - 4.4 QUALIFICATION OF A WELDING PROCEDURE
22 - 4.5 ASSESSMENT OF A TEST WELD TO QUALIFY A WELDING PROCEDURE
22 - 4.5.1 Method of assessment
22 - 4.5.2 Visual examination
22 - 4.5.3 Non-destructive examination
23 - 4.5.4 Destructive tests
25 - 4.5.5 Repeated tests
25 - 4.5.6 Portability of a qualified welding procedure
25 - 4.5.7 Period of validity
25 - 4.5.8 Disqualification of a qualified welding procedure
26 - 4.6 QUALIFICATION OF A WELDER
26 - 4.7 DISQUALIFICATION OF A WELDER
26 - 4.8 DESIGN OF A WELDED JOINT
26 - 4.8.1 General
28 - 4.8.2 Butt welds between components of equal nominal wall thickness
28 - 4.8.3 Butt welds between components of unequal nominal wall thickness
28 - 4.8.4 Reinforcement of a butt weld
28 - 4.8.5 Fillet weld
28 - 4.8.6 Dimensions of a fillet-welded repair sleeve
29 - 4.8.7 Socket weld
29 - 4.8.8 Seal weld
29 - 4.8.9 Reinforcement of a welded branch connection
29 - 4.8.10 Reinforcement of multiple openings
29 - 4.8.11 Forged branch fitting
29 - 4.8.12 Fabricated elbow or bend
29 - 4.8.13 Distance between welds
32 - 4.9 PRODUCTION WELDS
32 - 4.10 WELDING ON A GAS MAIN AFTER COMMISSIONING OR AFTER PRESSURE TEST
32 - 4.11 WELDING ONTO AN IN-SERVICE GAS MAIN
33 - 4.12 ASSESSMENT OF PRODUCTION WELDS AND REPAIR WELDS
33 - 4.12.1 General
33 - 4.12.2 Methods of examination and assessment
33 - 4.12.3 Visual examination
33 - 4.13 CRITERIA OF ACCEPTANCE FOR GIRTH WELD DISCONTINUITIES
34 - 4.14 REPAIR OF AN UNACCEPTABLE WELD
34 - 4.14.1 General
34 - 4.14.2 Repair
34 - 4.14.3 Inspection
34 - 4.15 REMOVAL OF AN ARC BURN AND CUTTING OUT OF AN UNACCEPTABLE WELD OR ARC BURN
35 - SECTION 5 CONSTRUCTION AND INSTALLATION
35 - 5.1 HANDLING
35 - 5.1.1 Storage
35 - 5.1.2 Transportation
35 - 5.1.3 Lifting
35 - 5.1.4 Stresses induced during laying
35 - 5.2 PROTECTION
35 - 5.2.1 Covering ends
36 - 5.2.2 Cleaning internally
36 - 5.2.3 Natural hazards
36 - 5.2.4 Electrically insulated joints
36 - 5.2.5 Cathodic protection connections
36 - 5.3 POSITIONING
36 - 5.3.1 Alignment
36 - 5.3.2 Valves
36 - 5.4 BURYING
36 - 5.4.1 Cover requirements and underground protection
37 - 5.4.2 Width of trenches
38 - 5.4.3 Grading
38 - 5.4.4 Bedding
38 - 5.4.5 Protection of coatings
38 - 5.4.6 Support of steel pipes
38 - 5.4.7 Backfilling
38 - 5.4.8 Reinstatement
39 - 5.5 INSPECTORS
39 - 5.6 ITEMS TO BE INSPECTED
39 - 5.7 MARKERS
39 - 5.8 COMPONENTS AND FABRICATED ASSEMBLIES
40 - SECTION 6 PRESSURE TESTING
40 - 6.1 GENERAL
40 - 6.2 SAFETY
40 - 6.3 TEST PRESSURES
40 - 6.3.1 Minimum test pressure
40 - 6.3.2 Maximum test pressure
41 - 6.3.3 Testing at operating pressure
41 - 6.4 TESTING MAINS AND SERVICES
41 - 6.5 HOLD PERIOD
41 - 6.6 PREPARATION OF THE TEST SECTION
41 - 6.7 PRESSURIZATION
42 - 6.8 TEST PROCEDURE
42 - 6.9 ASSESSMENT OF PRESSURE TEST
42 - 6.10 DISPOSAL OF TEST MEDIUM
42 - 6.11 REPORTS AND RECORDS
44 - SECTION 7 COMMISSIONING
44 - 7.1 SAFETY PRECAUTIONS
44 - 7.2 PURGING
44 - 7.2.1 General
44 - 7.2.2 Purge procedures
44 - 7.3 COMMISSIONING OF GAS MAINS
44 - 7.3.1 General
45 - 7.3.2 Mixing and dilution during purging
45 - 7.3.3 Planning
45 - 7.4 PRESSURE-LIMITING REGULATORS
45 - 7.5 OVER-PRESSURE SAFETY DEVICES
45 - 7.6 ODORANT FADE
46 - SECTION 8 MAINTENANCE
46 - 8.1 GENERAL
46 - 8.2 CORROSION PROTECTION SYSTEMS
46 - 8.3 ELECTRICAL HAZARDS
46 - 8.4 REPAIRS
46 - 8.4.1 General
46 - 8.4.2 Mains
46 - 8.4.3 Services
47 - APPENDIX A - REFERENCED DOCUMENTS
50 - APPENDIX B - APPLICATION OF VARIOUS TYPES OF TEST EQUIPMENT
50 - B1 GENERAL
50 - B2 VOLUMETRIC DISPLACEMENT METHODS
50 - B3 PRESSURE LOSS METHODS

Specifies materials, design, construction, installation, testing and maintenance requirements for steel piping systems covered by AS4645, for the distribution of fuel gas suitable for domestic, commercial or industrial uses, where the pressure of the gas is not greater than 1050kPa and the operating temperature range of the materials is from (30 degrees Celsius to 120 degrees Celsius; or where the hoop stress level is not greater than 20 percent of the specified minimum yield stress of the pipe used in that system.

This Standard specifies materials, design, construction, installation, testing and maintenance requirements for steel piping systems covered by AS4645, for the distribution of fuel gas suitable for domestic, commercial or industrial uses, where—the pressure of the gas is not greater than 1050kPa and the operating temperature range of the materials is from (30°C to 120°C; orwhere the hoop stress level is not greater than 20% of the Specified Minimum Yield Stress (SMYS) of the pipe used in that system.The Standard does not extend to the exclusions listed in Clause1.2. Some requirements of this Standard are suitable for consumer piping operating at >200kPa, being not otherwise provided in AS5601. The operator of such piping should decide which requirements are appropriate, and should obtain any necessary agreement from the regulator having jurisdiction over the operation of that piping.The relevant technical regulator may regard this standard as appropriate for other than fuel gas.

Originated as AS 1697-1981.
Second edition 2005.