All cast-iron steam and hot water boilers shall be provided with suitable washout openings to permit the removal of any sediment that may accumulate therein. Washout openings may be used for return pipe connections and the washout plug placed in a tee so that the plug is directly opposite and as close as possible to the opening in the boiler.
Pipe connections, if threaded, shall be tapped into material having a minimum thickness as specified in the following table:
MINIMUM THICKNESS OF MATERIAL FOR THREADED CONNECTIONS TO BOILERS
Size of pipe connection (inches) | Minimum thickness material required (inches) |
3/4 and under | 5/16 |
1 to 21/2, inclusive | 7/16 |
3 to 31/2, inclusive | 5/8 |
4 to 5, inclusive | 7/8 |
6 to 8, inclusive | 1 |
9 to 12, inclusive | 11/4 |
N.Y. Comp. Codes R. & Regs. Tit. 12 §§ 4-14.3