- Use glass wool as insulation and sound-absorbing material.
- The inner tube is a 3*5 Diameter perforated plate with a hole ratio of 32.65%.
| Specs | D | d | Inner_pipe_t | Outer_pipe_T | kg/m |
| 80 | 112 | 80 | 0.5 | 0.5 | 2.77 |
| 100 | 132 | 100 | 0.5 | 0.5 | 3.29 |
| 125 | 157 | 125 | 0.5 | 0.5 | 3.95 |
| 150 | 182 | 150 | 0.5 | 0.5 | 4.6 |
| 160 | 192 | 160 | 0.5 | 0.5 | 4.86 |
| 175 | 207 | 175 | 0.5 | 0.5 | 5.25 |
| 180 | 212 | 180 | 0.5 | 0.5 | 5.39 |
| 200 | 232 | 200 | 0.5 | 0.5 | 5.91 |
| 225 | 257 | 225 | 0.5 | 0.5 | 6.57 |
| 250 | 282 | 250 | 0.5 | 0.5 | 7.23 |
| 280 | 315 | 280 | 0.5 | 0.6 | 9 |
| 300 | 332 | 300 | 0.5 | 0.6 | 9.52 |
| 315 | 347 | 315 | 0.5 | 0.6 | 10.02 |
| 350 | 380 | 350 | 0.5 | 0.6 | 10.94 |
| 355 | 380 | 355 | 0.5 | 0.6 | 11.1 |
| 400 | 440 | 400 | 0.5 | 0.6 | 12.61 |
| 450 | 480 | 450 | 0.5 | 0.6 | 13.86 |
| 500 | 530 | 500 | 0.5 | 0.8 | 18.46 |
