Here are some facts about various gases which are useful for daily gas calculation and gas handling 

Pressure unit conversion

Conversion of different pressure units such as Bar, psi, Mpa, torr, ect 

Dew Point of Gas

Tells you how wet the gas is

Handling precaution to liquid nitrogen

Please take a look before handling this cool liquid

Gas Connection Assignment

Tells you what gas use what valve, usually

Physical properties of gases

Melting points, boiling points, vapor pressure , gas density of common gases. Very useful in calculation while in gas engineering