(a) The inside diameter of the vessel may not exceed 30 cm (12 inches) exclusive of flanges for handling or fastening devices and must have wall thickness and length in accordance with the following:
Inside diameter maximum
Threaded closure
Wall thickness minimum—Flanged closure
Length maximum
Inches
Cm
Inches
Mm
Inches
Cm
2
5
3/32
2.5
Not less than that prescribed for schedule 40 pipe