N.Y. Comp. Codes R. & Regs. tit. 12, § 4-13.2
Boiler openings.
Department of Labor
(a) Openings required.
Boiler openings must meet the requirements of section IV of the ASME Code.
(b) Threaded openings.
All threaded openings in a boiler shall be tapped into material having a minimum thickness as specified for the various standard pipe sizes in the following table:
MINIMUM THICKNESS OF MATERIAL FOR TAPPINGS
| Pipe size | Minimum thickness of material or length of thread required |
|---|---|
| (inches) | (inches) |
| 1 and under | ¼ |
| 1¼ to 2, inclusive | 5/16 |
| 2½ | 7/16 |
| 3 to 3½, inclusive | ⅝ |
| 4 to 5, inclusive | ⅞ |
| 6 to 8, inclusive | 1 |
| 9 to 12, inclusive | 1¼ |