It is closes a part of double wall pipe from butt end (ring insulation)
| Dv, mm | Dn, mm | Weight, kg |
| 350 | 350 | 0,56 |
| 400 | 400 | 0,59 |
| 450 | 450 | 0,7 |
| 500 | 500 | 0,72 |
| 550 | 550 | 0,84 |
| 600 | 600 | 0,85 |
| 650 | 650 | 0,98 |
| 700 | 700 | 0,99 |
| 750 | 750 | 1,12 |
| 800 | 800 | 1,12 |
| 900 | 900 | 1,25 |
| 1000 | 1000 | 1,38 |