RISK ASSESSMENT FOR GAS NETWORK IN THE CASE OF NATURAL DISASTERS

U ovom diplomskom radu u prvom djelu je opisana korozija, te njena podjela na elektrokemijsku i kemijsku koroziju, također i čimbenici koji sudjeluju u nastanku korozije kod plina i same plinske mreže. Kao izbor materijala za plinsku mrežu su navedena dva materijala koja se koriste, a to su PEHD cijevi i čelične bešavne cijevi. U današnje vrijeme se sve više upotrebljavaju PEHD cijevi. Zbog korozije mogu nastati ozbiljni problemi za okoliš kao i za samog čovjek sto može dovesti do smrtnog gubitka, te se plinovod mora zaštiti da slučajno ne dođe do toga navedenog stanja, a taj proces zaštite se osigurava katodnom zaštitom, izolacijom za ravne dijelove cjevovoda, polietilenskim trakama i premazima. U drugom dijelu tj. eksperimentalnom dijelu opisan je proces što bi se dogodilo kada bih nastao prekid tj. puknuće plinovoda za različite udaljenosti od magistralnog voda, i kakve bi posljedice bile za plinovod isto tako i za čovjekov život. Kroz povijest je sagledano koliko često je bilo na području Osijeka potresa, poplava, nevremena i pijavica te zaključeno hoće li doći do prekida plinovoda, požara ili eksplozija. Kroz cijeli plinovod je primijenjena katodna zaštita te potrebno njeno ispitivanje te održavanje.This master thesis has been divided into two separate, but thematically connected parts, of which the first has served as a theoretical introduction and the second as the description of the experimental methods. The corrosion and its division into electrochemical and chemical corrosion, have been studied in details in the first part of the thesis, as well as the factor that affects on the creation of the corrosion in gas, and the gas network itself. As the choice of the material that is used in making the pipelines in the gas network are PEHD and steal seamless pipes. But nowadays PEHD pipes are more commonly used. Corrosion can have numerous harmful effects on the environment and human beings, with possible lethal consequences on human life. Due to that fact, the gas line has to be adequately protected to avoid above mentioned states. This process of protection is assured with cathode protection, insulation for flat parts of pipeline, polyethylene ribbons and coatings. In the second, experimental part of thesis, it has been studied the possible situation of pipeline failure or brake. Possible consequences for the pipeline itself and for the human life, have been described taking into consideration different distances of the failure from the main pipeline. Natural disasters in the area of Osijek that can lead to gas pipeline failure or brake, such as earthquakes, floods, storms and waterspouts, have been studied towards the end of this master theses, and based on the collected data, certain conclusions have been drawn. It has also been noted that throughout the whole pipeline has been applied cathode protection, and that it is necessary to regularly review it and maintain it