AS/NZS 2739:1999

1 - AS/NZS 2739:1999 NATURAL GAS (CNG) FUEL SYSTEMS FOR VEHICLE ENGINES
4 - PREFACE
5 - CONTENTS
7 - SECTION 1 SCOPE AND GENERAL
7 - 1.1 SCOPE
7 - 1.2 OBJECTIVE
7 - 1.3 REFERENCED DOCUMENTS
7 - 1.4 NEW DESIGNS AND INNOVATIONS
7 - 1.5 DEFINITIONS
7 - 1.5.1 Approved, approval
8 - 1.5.2 Authorized person
8 - 1.5.3 Authority
8 - 1.5.4 Capacity (of a cylinder)
8 - 1.5.5 CNG (Compressed natural gas)
8 - 1.5.6 Cylinder
8 - 1.5.7 Cylinder compartment
8 - 1.5.8 Cylinder sub-compartment
8 - 1.5.9 Design pressure
8 - 1.5.10 Fuel shut-off device
8 - 1.5.11 Fuel metering system
8 - 1.5.12 Fuel service line
9 - 1.5.13 Gas air mixer
9 - 1.5.14 Ignition source
9 - 1.5.15 Licensed installer
9 - 1.5.16 May
9 - 1.5.17 NGV
9 - 1.5.18 Non-return valve
9 - 1.5.19 Pressure
9 - 1.5.20 Pressure relief device
9 - 1.5.21 Professional engineer
9 - 1.5.22 Rated working pressure
9 - 1.5.23 Refuelling interlock device
10 - 1.5.24 Regulator
10 - 1.5.25 Removable cylinder
10 - 1.5.26 Shall
10 - 1.5.27 Should
10 - 1.6 VEHICLE MODIFICATIONS
11 - 1.7 MINOR ALTERATIONS
11 - 1.8 ENGINE MANAGEMENT SYSTEM
11 - 1.8.1 Alterations
11 - 1.8.2 Closed loop systems
11 - 1.9 APPROVED EQUIPMENT
11 - 1.10 PREVIOUSLY USED EQUIPMENT
11 - 1.10.1 Provisions
11 - 1.10.2 Prohibitions
11 - 1.11 WORKING AREA AND SAFE PRACTICES
12 - SECTION 2 COMPONENTS
12 - 2.1 GENERAL SUITABILITY
12 - 2.1.1 General
12 - 2.1.2 Suitability for pressure
12 - 2.1.3 Suitability for installation
12 - 2.2 MOVING PARTS
12 - 2.3 MODIFICATION
13 - SECTION 3 FUEL SYSTEM COMPONENTS
13 - 3.1 APPLICATION
13 - 3.1.1 General
13 - 3.1.2 Fuel supply system components
13 - 3.1.3 Use of multiple components
13 - 3.2 CYLINDER
13 - 3.2.1 General
13 - 3.2.2 Use of removable cylinders
13 - 3.2.3 Cylinder painting
14 - 3.3 COMPONENTS FOR REMOVABLE CYLINDERS
14 - 3.4 CYLINDER VALVE
14 - 3.5 REFUELLING CONNECTION
14 - 3.5.1 Design of connection
14 - 3.5.2 Dust cap
14 - 3.5.3 Refuelling interlock device
14 - 3.6 REFUELLING NON-RETURN VALVE
14 - 3.7 LOCATION OF REFUELLING CONNECTION
15 - 3.8 REFUELLING INFORMATION PLATE
16 - 3.9 SERVICE ISOLATION VALVE
16 - 3.10 FUEL FILTER
16 - 3.11 FUEL SHUT-OFF DEVICE
16 - 3.12 FUEL FLOW REGULATION DEVICE
16 - 3.13 CONTENTS INDICATOR
16 - 3.14 CYLINDER COMPARTMENTS AND SUB-COMPARTMENTS
16 - 3.14.1 Internal cylinders
17 - 3.14.2 Safety device discharge
17 - 3.14.3 Construction
17 - 3.14.4 Ventilation
18 - 3.14.5 Conduits
19 - 3.15 MOUNTING OF FUEL CYLINDER
19 - 3.15.1 Access to valves
19 - 3.15.2 Attachment to vehicle
20 - 3.15.3 Alternate anchoring
21 - 3.15.4 Multiple cylinders
21 - 3.16 CYLINDER LOCATION AND GROUND CLEARANCES
22 - 3.17 PROTECTION
23 - 3.18 HEAT SHIELDING
25 - SECTION 4 FUEL SERVICE LINE
25 - 4.1 APPLICATION
25 - 4.2 RIGID PIPING
25 - 4.3 FLEXIBLE PIPING
25 - 4.4 JOINTS AND CONNECTIONS
25 - 4.5 PIPING INSTALLATION AND PROTECTION
26 - 4.6 PIPING OR FITTINGS IN ENCLOSED SPACES
26 - 4.7 TRAILERS AND SEMITRAILERS
27 - 4.8 PREVIOUSLY USED EQUIPMENT
27 - 4.8.1 Provisions
27 - 4.8.2 Prohibitions
27 - 4.9 FUEL HOSE FOR PRESSURE NOT EXCEEDING 100 KPA
27 - 4.10 BREAKAWAY COUPLING
28 - SECTION 5 FUEL CONTROL EQUIPMENT
28 - 5.1 APPLICATION
28 - 5.2 FUEL METERING SYSTEM
28 - 5.3 FUEL SELECTOR
28 - 5.3.1 General
28 - 5.3.2 Fuel change over system
29 - 5.3.3 Bi-fuel type
29 - 5.4 PETROL SYSTEM MODIFICATIONS
29 - 5.5 ELECTRICAL WIRING
30 - 5.6 ENGINE MANAGEMENT SYSTEM
31 - SECTION 6 INSPECTION, TESTING AND COMMISSIONING
31 - 6.1 APPLICATION
31 - 6.2 USED EQUIPMENT
31 - 6.3 MODIFICATIONS AND REPAIRS
31 - 6.4 PRECAUTIONS
32 - 6.5 INSPECTION
32 - 6.6 LEAK DETECTION
32 - 6.7 CYLINDER
32 - 6.8 INSTALLATION TEST
32 - 6.8.1 General
32 - 6.8.2 Gastightness of compartment and sub-compartment
32 - 6.8.3 Leak testing of gas system
32 - 6.8.4 Test of fuel changeover system
32 - 6.8.5 Water system tests
33 - 6.8.6 Visual inspection
33 - 6.9 PERIODIC INSPECTION
33 - 6.9.1 General
33 - 6.9.2 System check
34 - 6.10 NON-RETURN VALVE TEST
35 - SECTION 7 CERTIFICATION, COMPLIANCE PLATE, MARKINGS AND LABELS
35 - 7.1 APPLICATION
35 - 7.2 CERTIFICATION
35 - 7.3 COMPLIANCE PLATE
35 - 7.4 LABELS AND MARKINGS
35 - 7.4.1 Vehicle identification
36 - 7.4.2 Refuelling information plate
36 - 7.4.3 Selector
36 - 7.5 OPERATING INSTRUCTIONS
37 - APPENDIX A - LIST OF REFERENCED DOCUMENTS
39 - APPENDIX B - REGULATING AGENCY INFORMATION
41 - APPENDIX C - NEW ZEALAND REFUELLING CONNECTION AND DUST PLUG
42 - APPENDIX D - LEAK DETECTION METHODS
42 - D1 SCOPE
42 - D2 COMBUSTIBLE GAS DETECTORS
42 - D3 TRACE GAS DETECTORS
42 - D4 FOAMING AGENTS
43 - D5 TOTAL IMMERSION

Sets out the specific requirements for natural gas (CNG) fuel systems for engines mounted on motor vehicles, either for the propulsion of the vehicles or for driving some auxiliary function. It also provides requirements for the design and construction of component parts as well as their installation, testing, commissioning and periodic inspection.

This Standard specifies requirements for natural gas (CNG) fuel systems for engines mounted on motor vehicles, either for the propulsion of the vehicles or for driving some auxiliary function, e.g. a mixer or a pump. It provides requirements for the design and construction of component parts, and for their installation in vehicles, and for tests, commissioning, and periodic inspection.The Standard may be applied to stationary engines and small engine-powered appliances such as floor sweepers, polishers and trolleys, where it is relevant.This Standard does not apply to other natural gas usage, such as the gas supply system for appliances in caravans, mobile homes or for the propulsion of marine craft.This Standard does not cover the areas where major structural modifications are to be carried out to the vehicle (major structural modifications are those not defined in Clause 1.7). Prior to commencement of such work guidance should be sought from the vehicle manufacturer or a professional engineer who is experienced in the automotive disciplines.

First published in Australia as AS 2739-1984.
Second edition 1992.
First published in New Zealand in part as NZS 5422.2:1980.
Second edition 1987.
NZS 5422.3 first published 1991.
AS 2739-1992, NZS 5422.2:1987 and part of NZS 5422.3:1994 jointly revised, amalgamated and designated AS/NZS 2739:1999.