This Standard specifies requirements for natural gas (NG) 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. It applies to all vehicle types, e.g. rigid chassis, articulated chassis and semitrailers.This Standard does not cover the areas where major structural modifications are to be carried out to the vehicle. 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.This Standard does not apply to NG usage such as the gas supply system for appliances in caravans, mobile homes, forklifts, floor sweepers, polishers, tow tractors, elevating work platforms and industrial engines (refer to AS 4983) or for the propulsion of marine craft (refer to AS 4732).

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 redesignated as AS/NZS 2739:1999.Fourth edition 2003.Fifth edition 2009. Originated in Australia as AS 2739-1984. Originated in New Zealand as NZS 5422.2:1980. Previous edition AS/NZS 2739:2003. Fifth edition 2009.