Provision of fire emergency and isolation for multilayer pipe

Purpose

The purpose of this advisory note is to inform licensees and contractors in the gasfitting industry about the updated requirements for providing fire emergency isolation in gas installations using multilayer pipes in New South Wales. These updates, in line with AS/NZS5601.1:2022, aim to enhance safety by ensuring that systems are in place to automatically shut off the gas supply during a fire, thereby protecting both the installation and the occupants.

Issue

Amendment 2 of AS/NZS5601.1 has been released on 6 September 2024 (AS/NZS5601.1:2022) and becomes the referenced standard from 6 March 2025.

Multilayer piping has less durability and mechanical strength than metallic piping when subjected to fire.

AS/NZS5601.1:2022 requires the provision of emergency isolation when multilayer pipe is installed as part of the consumer piping.

All gas installations in NSW must comply with the Gas and Electricity (Consumer Safety) Act 2018. Any installation not conforming to AS/NZS 5601.1:2022 is considered non-compliant. 

Reference

 Gas and Electricity (Consumer Safety) Act 2018

AS 5601.1:2022 - Gas installations

5.2.11 Provision of fire emergency isolation for multilayer pipe

Where multilayer pipe is used as part of consumer piping, the following requirements for fire emergency isolation shall apply:

• The installation shall be fitted with a system that will shut off the gas supply when the fire safety system operates.

• The method of isolation shall be a single class 1 safety shut-off valve that meets the requirements of AS 4629 and automatically isolates the gas flow to the building when de-energised. This valve shall:

  • operate only when an active fire safety system operates; and
  • be located prior to any multi-layered pipe and be as close as practicable to the gas supply point to the building, and readily accessible.

  Note 1: Single class 1 safety shut-off valves that meet the requirements of AS 4629:2005 are equivalent.

• The system shall provide pressure proving of the downstream installation prior to restoration of the gas supply.

Alternatively, for a Class 1a building in Australia, or detached or multi-unit dwelling in New Zealand, a system or devices shall be provided that automatically shuts off the gas supply if gas tightness is adversely affected. The system or devices which shuts off the gas supply shall be:

• in an accessible location prior to any multilayer pipe it is designed to protect; and
• sized, located and commissioned in accordance with the manufacturer’s instructions to ensure safe and correct operation and avoid nuisance tripping.

Where multiple devices are required within a building, they shall be in accessible locations and prior to the multilayer pipe they are designed to protect.

Excess flow valves shall conform to DIN 30652-1 or an equivalent standard.

Multilayer pipes shall not be installed in buildings where the building design is such that a system or devices to shut off the gas supply cannot be installed. Alternative consumer piping shall be installed in accordance with Clause 4.2.

Note 2: Multilayer piping has less durability and mechanical strength than metallic piping when subjected to fire.

Note 3: In this clause an active fire safety system is:

• an automatic active system or manually activated system that provides a fire alarm condition used in a building to notify occupants within the building of a fire emergency by the sounding of an alarm throughout all occupied areas, via an emergency warning and intercom system, or via a paging system; and
• interlocked to the fire detection control and indicating equipment. 
  More information is provided in the following documents:
  • For Australia, refer to AS 1670.1 and AS 2118.
  • For New Zealand, refer to NZS 4512, NZS 4515:2009, and NZS 4541.

Note 4: To avoid nuisance trips and unintended interruption to the gas supply to a building, the gas supply should only be shut-off when all the occupants of the building are alerted to the fire incident.

Note 5: Local smoke alarms within an apartment that are intended to alert apartment occupants of localised smoke should not shut-off the gas supply to the building.

Note 6: Class 1a buildings are defined in the National Construction Code (NCC) Australia.

Note 7: Devices that automatically shut off the gas supply may be activated by methods of sensing pressure loss or excessive gas flow conditions.

Note 8: This clause also applies to the alteration of consumer piping using multilayer pipe in an existing installation but does not apply to the replacement of an appliance in an existing installation.

Note 9: When using a device within a building with mechanical joints (e.g. excess flow valves) see Clause 5.3.8 for piping in a concealed location and Clause 5.3.12 for ventilation in a concealed location.

Note 10: The requirements for fire emergency isolation do not apply to multilayer piping that is only located below ground external to a building.

Relevant definitions

AS5601.1 2022

1.3.1.1 - Readily accessible 

Access can be gained without hazard, undue difficulty, or use of a tool.

1.3.39 - Fire safety system

One or any combination of the methods used in a building to:

• warn people of a fire emergency;
• provide for safe evacuation;
• restrict the spread of fire; or
• extinguish a fire,

which includes both active and passive systems.

National Construction Code (NCC)

Class 1a buildings

Class 1a is one or more buildings, which together form a single dwelling including the following:

• a detached house; or
• one of a group of two or more attached dwellings, each being a building, separated by a fire-resisting wall, including a row house, terrace house, town house or villa unit.

Requirements

When using any type of multilayer gas pipe as part of the consumer piping system, consideration must be given to the requirement of installing a fire emergency isolation in a readily accessible place.