Used for pipeline wiring, encounter nodes or in the wall corner turn, connect / butt the two ends of the same nominal diameter of the pipe.
| NO. | Diameter/mm | Thickness/ mm |
 1 | 15 | 1.5 |
| 2 | 18 | 1.5 |
| 3 | 22 | 1.5 |
| 4 | 28 | 1.5 |
| 5 | 35 | 1.5 |
| 6 | 42 | 1.5 |
| 7 | 54 | 1.5 |
| 8 | 76.1 | 2 |
| 9 | 88.9 | 2 |
| 10 | 108 | 2 |
