(a) Material used in the tank must be steel of good weldable quality and conform with the requirements in Sections V, VIII, and IX of the ASME Code (IBR, see § 171.7 of this subchapter).
(b) The minimum thickness of metal, exclusive of lining material, for shell and heads of tanks shall be as follows:
| Tank capacity
| Minimum thickness (inch)
|
|---|
| Not more than 1,200 gallons |
1/4
|
| Over 1,200 to 1,800 gallons |
5/16
|
| Over 1,800 gallons |
3/8 |