1 First, the number 3 of the cylinder stamp number represents the cylinder number.

2. Secondly, there are 13 pieces of information in the cylinder, which are represented by different numbers.

3. Finally, "1" stands for filling gas name, the number "2" stands for chemical molecular formula, the number "3" stands for cylinder number, and the number "4" stands for hydraulic test pressure (code name TP)MPA, etc. This is the way to check the model of liquefied gas.