Natural Gas is transported and supplied to the consumer's premises through an extensive pipeline network that is based on the Main Steel Pipeline that brings the gas from the source to the city. The gas, commonly known as Piped Natural Gas (PNG), is routed via smaller pipes to homes, offices, stores, factories and all major demand centers in the city. Along the steel network, CNG stations are located, where NG is compressed and distributed to vehicles as a fuel. Pressure regulators maintain the requisite pressure in the pipeline. Metering device installed in the customer's premises records the units of gas consumed by the user based on which invoicing is done.