Specification and size comparison table of gas pipe.doc can be downloaded and printed

Divide 1 inch into 8 equal parts:
1/8 1/4 3/8 1/2 5/8 3/4 7/8 inch.
It is equivalent to what is usually said: 1 branch to 7 branches,
Smaller dimensions are represented by "16, 1/32, 1/64", and the unit is still inch.
If the denominator and numerator can be reduced (for example, the numerator is 2, 4, 8, 16, 32), they should be reduced.
The inch display is marked with two reverses at the upper right corner, such as 1/2“
For example, DN25 (25mm, the same below) water pipe is English system
The 1 "water pipe is also the 8 branch pipe before liberation. The DN15 water pipe is British
1/2 "water pipe is also the 4 branch pipes before liberation. For example, DN20 water pipe is English system
The 3/4 "water pipe is also the 6 intermediate pipes before liberation.