Protective casings are designed for prevention of aggressive media spattering in case of pipeline flange coupling seal failure.
Polyethylene casings (GOST 16337-77) are produced in accordance to technical specification 2291-012-22955745-2014 for pipelines with nominal operating pressures up to 1.6 MPa (16 kgf/cm2) having the following pipeline diameters (OD): 57, 76, 89, 108, 133. The connecting dimensions are given in the table. It is possible to use a casing having OD 57 for dimension types OD 14, 18, 25, 32, 38 by means of applying additional rings centring the casing.
| OD,mm | d,mm | D,mm | h,mm | H,mm | Weight,kg |
| 57 | 65 | 178 | 75 | 83 | 0.2 |
| 76 | 84 | 198 | 90 | 98 | 0.4 |
| 89 | 97 | 213 | 90 | 98 | 0.5 |
| 108 | 115 | 233 | 90 | 98 | 0.6 |
| 133 | 140 | 256 | 100 | 108 | 0.8 |
Polyethylene casings with centring rings of fluoroplast-4
| OD,mm | d,mm | D,mm | h,mm | H,mm | Weight,kg |
| 14 | 19 | 178 | 75 | 83 | 0.4 |
| 18 | 23 | 178 | 75 | 83 | 0.4 |
| 25 | 30 | 178 | 75 | 83 | 04 |
| 32 | 37 | 178 | 75 | 83 | 0.4 |
| 38 | 43 | 178 | 75 | 83 | 0.4 |
| 45 | 50 | 178 | 75 | 83 | 0.4 |