where are pipelines
The casing in construction engineering is generally used when water supply and drainage pipes, electrical pipes, cables, civil ventilation pipes and other walls are pierced.2. The casing of water supply and drainage pipes: use the sealed casing on the closed wall of civil air defense (the length is generally 5cm on each side of the thickness of civil defense wall);Rigid or flexible casing is used when penetrating the pool and outer wall. The rigid casing is the same thickness as the wall. The edge of the flexible casing tube protrudes about 5~8cm outside the wall, and the outside is flush with the wall.3. Bushing for electrical pipes and cables: rigid waterproof bushing is used in the outer wall and the inner side is flush with the wall according to the length required by the design.4. Casing for civil air defense and ventilation pipes: airtight casing, the length of which is usually 15cm on each side of the thickness of civil defense wall or as required in the design drawing.