TEST ANSWERS

Q1 what is the molar mass value of hydrogen? 2.016 kg/kmol [check on line!]

Q2 after 30 june 2003 all products for hazardous areas placed on the market or put into service will have to conform to a European Cummunity Directive. Which one? ATEX 94/9/EC [read more]

Q3 how is classified the area close a ball valve outdoor installed in a pipe in which flows methan at 3 bar pressure and at 30 °C? zone 2 with an spherical extension of 1m radius [how can I easly have this results?]