Section R. 325.1627 - Construction of wells; steel casing and types of jointsRule 127.
(1) Steel pipe that is used as permanent well casing shall be watertight throughout its length and shall have threaded or welded joints.(2) Couplings that are used on threaded steel casing shall be recessed or reamed and drifted couplings that are manufactured in compliance with the standards of ASTM specification A 589-89a or API specification 5L-90. The specifications are adopted by reference in R 325.1610. Couplings shall have a design, taper, and type of thread that is consistent with the thread of the pipe and threads shall not be exposed on the pipe.(3) Welded joints shall be in compliance with the specifications of table 2 and provide a structurally sound and watertight joint. Pipe ends shall be free of oil, grease, heavy rust, paint, or other foreign materials, except for tightly adherent mill scale. The weld bead shall be chipped and brushed to remove slag and other extraneous materials between passes. Table 2
Minimum Number of Passes for Welding Steel Casing
| Pipe Diameter | Minimum Number |
| (inches) | passes |
| 4 | 2 |
| 5 | 2 |
| 6 | 3 |
| 8 | 3 |
| 10 or larger | 4 |
Mich. Admin. Code R. 325.1627