What Makes the Pipeline Safe

Natural gas pipelines are generally regarded as the safest mode of energy transportation in the world today. Natural gas is transported underground in high strength steel pipes. The strength and quality of the steel, the depth of the pipe and the thickness of the pipe all help to improve safety.

To ensure safety, the pipeline is located in a designated ‘Pipeline Easement’ which is a right-of-way allowing access for necessary inspections or maintenance. There are also restrictions as to what activities can be undertaken within the pipeline easement without prior consultation with the pipeline operator. Generally, any activities which disturb the natural ground level to a depth greater than 300 mm must be approved by the pipeline operator, however, we strongly recommend that a free Dial Before You Dig query is undertaken before any type of excavation is undertaken.

During construction, each joining weld is x-ray tested. Before natural gas is allowed to enter the pipe water is injected at 125-150 per cent of the maximum operating pressure to test the pipe’s integrity.

The pipeline has a protective coating to prevent corrosion and is further protected by a cathodic protection system. This system sends a small electrical current along the steel pipe and into the ground. This protects any bare steel from corroding.

The NQGP is monitored 24 hours per day via the supervisory control and data acquisition (SCADA) system. The SCADA system scans sites along the pipeline every 10 seconds and relays the information back to a control room. The data is analysed for such things as gas pressure, temperature, quality and flow. Valves can be remotely closed to vary gas flow and pressure to ensure the pipeline is safe.

Gas Safety

Natural gas is odourless. While in many part of Australia the gas is odorised to give it a distinct smell, the NQGP is not odorised as it is not currently reticulated in built up areas.

Flammability of Natural Gas

For combustion to occur, three things are needed: Fuel (in this case, gas), air and ignition. If you take any one of these away, the fire is extinguished.

For natural gas to be flammable it needs to be within a certain range of concentration.

The concentration must be between 5% and 15%. If the concentration is below 5%, there is not enough to support combustion. If the concentration is above 15%, there is too much gas to support combustion.