Energy costs constitute about 20-25% of the total production cost in an integrated steel plant. Energy efficiency is, therefore, essential for economic profitability. Production processes in this steel plant require, among other things, fuel gas networks that have to reliably supply a wide variety of gas grades and blends to a large number of process consumers. Due to the complex nature of production scheduling, these gases must always be available when needed. The reliability of energy efficiency calculations can be increased by using the advanced data validation and reconciliation method in fuel gas network balancing. The identification of the measurement system of the fuel gas network in a selected integrated steel plant was carried out. After determining measurement redundancy from the point of view of the advanced data validation and reconciliation method, it was used to credibility the measurements. Mass and energy balance equations were formulated for the analyzed fuel gas network and exemplary calculations for advanced measurement validation were performed. The calculation results showed that due to the usually greater uncertainty of measurements in industrial conditions, it was found necessary to use the advanced data validation and reconciliation method in balancing the fuel gas network.