PERCENTAGE OF GAS IN GASMIG’S DISTRIBUTION NETWORK
The table below shows the history of gas leakage at Gasmig’s distribution network
Gas leakage is controlled by measuring the volumes discarded in routine operations, such as preventive or corrective maintenance, alignment of new customers, atypical interventions to change the pipeline routes, in addition to prevent accidents with disruption in the Distribution
The total volume discarded in 2015 was 9.500 m³, mainly due to the accidents caused by not authorized excavations of third parties’ works, with disruption in the gas distribution network. Besides that, there were gas leakage due to the maintenance and operation services. There were few leaks resulted from accidents on the network caused by third parties’ works. This is because Gasmig’s distribution network is well signaled, and is composed of special carbon steel pipes and welded seams, buried block valves and connections welded to the tubes. All welding in the steel pipes are rigorously inspected as required by the ANSI (American National Standard Institute) B 31.8 or ABNT NBR 12712 (Brazil). ABNT NBR standards are used in the project and construction phases of the pipeline. In addition, the High Density Polyethylene – HDPE tubing is being used in residential networks.
After the construction is assembled, all the gas piping systems line entire section undergoes were tested to prove strength of pipelines and mains a pressure that ensures the tightness (absence of leaks) and to demonstrate that it doesn’t leak the resistance to internal pressure, with adoption of the criterion hydrostatic test pressure of 40% above the Maximum Allowable Operating Pressure for 24 hours; the pipeline is considered approved if its pressure drops to 0.5% below the test pressure, with no leaks, which is a more rigorous procedure than the requirements stablish by ANSI B 31.8 or ABNT NBR 12712 (Brazilian standard for gas pipelines).
Gasmig installs over its entire network a complete signaling system (signs, beacons, pole stickers and tacks on the floor) so that the city administration, electricity, water and phone utilities, and the population are aware of the gas network location. In addition, the company offers a free 24 hour telephone service through which citizens can contact the company in case of any damage to the network, suspected gas leaks and other incidents.
We also highlight that Gasmig has an Emergency Action Plan (EAP) in place, with the goal of providing fast, efficient and coordinated actions in joint action with the Fire Department, Civil Defense and the Military Police. The Plan promotes internal and external drills as well as periodic reviews of standards and procedures for emergency situations in the system.