Among the all insulators manufactured by PJSC “SZWI”, the main place is occupied by the covering of various applications used in the production of low-oil, gas-insulated and air circuit breakers, current transformers, high-voltage bushings and arresters.
The plant produces cylinder-shaped and cone-shaped covering with a maximum height up to 5525 mm. The covering with a height up to 2000 mm is made from a solid stock. Large-sized insulators are glued together of individual elements using epoxy-diane resin, providing the gluing integrity during the operation under a load at bending of 235 kg/cm2.
| Covering name | Designation of the drawing | GOST, TU, IEC | Voltage class, kV | The length of the insulation distance is not less than, cm | N, mm | D outer, mm | Weight, kg | Rough drawing | |
| nom. | prev. deviation ±10% | ||||||||
| П 250/210 УХЛ2 | НИЮД.757524.019 | GOST 5862-79 | — | — | 250 | 290 | 13,8 | 1,38 |  |
| П 330/55 О | НИЮД.701 | IEC 62155:2003 | 15 | 44 | 330 | 118 | 3,30 | 0,33 | |
| П 470/180 | ИНЯЖ.757524.003 | GOST 5862-79 | 35 | 70 | 470 | 330 | 32,0 | 3,2 | |
| П 540/55 О | НИЮД.702 | IEC 62155:2003 | 30 | 95 | 540 | 124 | 5,50 | 0,55 | |
| П 645/55 О | НИЮД.700 | IEC 62155:2003 | 36 | 95 | 645 | 109 | 5,30 | 0,53 | |
| П 645/80 О | НИЮД.703 | IEC 62155:2003 | 36 | 95 | 645 | 134 | 6,80 | 0,68 | |
| П 760/230 УХЛ1 | АТКИ.686174.020 | GOST 5862-79 | 40 | 105 | 760 | 370 | 65,0 | 6,5 | |
| П 850/200 | ИШУМ.757523.111 | GOST 5862-79 | — | — | 850 | 350 | 60,0 | 6,0 | |
| ПРПТ-1290/590 У3 | ИМЖК.757524.053 | TU 16-528.155-76 | — | — | 1290 | 780 | 424,0 | 42,4 | |
Interpretation of the conventional value of a covering type:
P – covering;
R – arrester;
PT – DC current;
Numerator of the fraction is the height of a covering, mm;
Denominator of the fraction is the maximum inner diameter of a covering, mm;
U – climatic version;
3 – placement category (indoors).
The material of the insulation part is a ceramic electrotechnical material of a subgroup 110 GOST 20419-83.