摘要：Natural gas transmission is strongly connected with fire and explosion safety. Generally, explosion hazard occurs, when at least 5% of natural gas is present in the atmospheric air. As high-pressure gas transmission infrastructure includes many potential sources of gas releases, both operational and accidental, many different cases should be considered. To properly face the potential hazard of explosive atmosphere formation, the hazardous zone should be estimated. There are some guidelines, describing the process of hazardous zones calculating. This paper compares calculations of such hazardous based on Polish and European standards which are also valid in Poland. Calculations are focused on releases that may occur on the safety block and relief valve systems.
