Different Gas has got different molecular weight and density. Gas Weight Chart gives us information regarding molecular weight and densities of different gases. This information of respective weight and density of particular gas is of utmost importance when two or more gases have to be mixed together in different particular concentrations of PPM or Percentage.

Some applications need two or more gases to be mixed together in different respective concentration. Based upon various physical, chemical properties coupled with particular gas’s reactivity, some gases cannot be mixed with other gas. Gas Compatibility Chart gives us information regarding possibility of mixing / non-mixing of one gas with another.

LEL and UEL refer to Lower Explosive Limit & Upper Explosive Limit. The LEL & UEL gives us the information regarding the range within which a flammable / fuel gas will burn in the presence of ignition source and air / oxygen. Below LEL, the presence of Fuel gas is too low to burn and above UEL, the presence of Fuel Gas is too high to burn.

Different gases have different nature. Some are Inert, some are flammable, some are toxic and some are corrosive in nature. Based upon different nature of gases, various different types of valves have been allowed to be fitted as per Govt. Rules. For the safety reasons, the gas cylinders of particular group of gases having same nature, has to be fitted with same type of valve.