Gas Installation Requirements for Commercial Kitchens

What You Need to Know

Every commercial kitchen that runs gas appliances must meet AS/NZS 5601.1:2022. This standard covers how gas pipes are sized, how appliances connect, how ventilation ties into the gas supply, and what happens in an emergency. The 2022 edition replaced the 2013 version and has been mandatory since 30 March 2023. If your kitchen has more than one gas appliance, you now need a dedicated isolation system with signage. Miss this, and the job will not pass inspection.

• Where more than one commercial catering appliance is installed, fit either a quarter-turn manual shutoff valve or an emergency stop button with solenoid valve and pressure proving to isolate all appliances (AS/NZS 5601.1:2022, Clause 5.2.9.2)
• Signage must clearly identify the isolation point (Clause 5.2.9.2)
• Minimum clearance from a gas cooker to a rangehood is 650 mm for new kitchen installations (Clause 6.10.1.1)
• Semi-rigid connectors are not permitted for commercial catering equipment (Clause 6.10.2.8)
• Freestanding equipment using a hose assembly must have the connection point extended to a higher level in rigid pipe (Clause 6.10.2.7)
• Combustible surfaces next to commercial catering equipment need thermal protection per Appendix C
• Ventilation must be proven before gas flows. The interlock must fail safe, confirm no-flow state before start-up, and sense actual air movement using an air pressure differential switch (Clause 6.4)
• Consumer piping must pass a soundness test at operating pressure or 2.0 kPa, whichever is greater. Test runs for 5 minutes (Appendix E)
• Multilayer pipe in new buildings requires automatic fire isolation through a fire-interlocked shut-off valve

Picture a commercial kitchen fit-out with a 6-burner range, a deep fryer, a combi oven, and a salamander grill. That is four gas appliances, so Clause 5.2.9.2 applies. You need a single quarter-turn isolation valve at a spot every kitchen worker can reach, or an emergency stop button wired to a solenoid valve with pressure proving.

The ventilation interlock is just as important. Before any gas flows, the system must confirm the exhaust hood fans are running. An air pressure differential switch on the exhaust duct does this job. If the fan stops mid-service, the gas cuts off automatically. This is not optional. It is the fail-safe that stops carbon monoxide building up in a closed kitchen.

For pipe sizing, the 2022 edition updated its calculation tables to use the Churchill friction factor equation. This gives more accurate results for larger pipe diameters and longer runs. On a typical kitchen fit-out, you size the gas main for the total connected load of all appliances running at once. Natural gas pressure rises about 0.50 kPa per 100 m of vertical rise, so high-rise kitchens need that factored into the design.

The ban on semi-rigid connectors for commercial catering equipment is a big change from the 2013 edition. You must now use either rigid pipe or approved hose assemblies with high-level connection points. If an appliance needs to slide out for cleaning, a hose assembly connected at the top of the rigid pipe in a U-shape is the compliant method.