Revision of Standard for reticulated gas
2 May 2025
The draft of a revised specification for reticulated gas (NZS 5442) is open for public consultation until 2 June 2025.
Powerco’s Bruce Monk, chair of GasNZ’s Technical Advisory Group, says the revised standard covers the blending renewable gases (such as biomethane and hydrogen) supplied to consumers, to help ensure that the gas is suitable for transportation, and safe to use in gas-burning appliances and equipment.
The Standards New Zealand committee reviewing the standard was chaired by David Innes from Firstgas, and Monk says he deserves a special mention. “He provided direction and carried out research vital to the outcome.”
The committee decided to drop the word ‘natural’ from its previous title to reflect that blending other gases with methane-based gas in the network is an acceptable practice.
While there are no specific limits on the level of biomethane that can be blended, the committee determined that blending hydrogen is restricted to injection within the local distribution system of the reticulated gas network and is limited to a maximum of 10 percent.
The committee said the rationale for this requirement comes from a body of international research.
“The limits set by the committee are designed to remain within the range set by the Wobbe index parameters, while being consistent and aligned with hydrogen blending limitations in the latest revision of AS 4564, General-purpose natural gas.”
Bruce Monk says an informative appendix has been added, giving details of what to consider when injecting hydrogen into the gas network.
This standard specifies limits for gas characteristics and components that are consistent with safely operating the existing population of appliances.
It provides certainty for those who manufacture appliances for the New Zealand market, and for installers who set up these appliances.
By specifying limits for contaminants, it seeks to ensure the integrity of transportation systems and prevent operating problems for most gas consumers.
The consultation document is available through the following link:
NZS 5442 Specification for reticulated natural gas - Standards New Zealand - Citizen Space