1. For wires and pipes hidden in walls, buried in underground non-combustible bodies, and for household installations such as rural buildings, it is necessary to adopt PVC threading pipes that meet the requirements of the Ministry of Construction Standard JG3050-1998 “Insulating electrical sleeves and fittings for buildings”, which have certain flame retardancy and meet the requirements of physical and mechanical properties. Meticulous and local.
2. For high fire risk places, such as hotels, restaurants, shopping malls (large supermarkets), libraries, singing and dancing *** and other public gathering places, the suspended ceiling and the line in the floor should be protected by fire-retardant PVC threading pipes with higher combustion performance because there are more combustible and flammable materials in the ceiling and floor.
3. Fire-retardant PVC threading pipes meeting the Ministry of Public Security standards shall be mandatory for fire-fighting distribution lines and fire automatic alarm systems.
4. For the renovation of open-laid electrical lines, interior decoration and second decoration of houses, and the renovation of old and old buildings, the open-laid lines (hidden in ceiling and floor) must be used, and the flame-retardant PVC threading pipes with combustion performance above B1 level must be used.