Flexible waterproof casing is applied to the pipe through the wall between the subject requirement of vibration or water proof structure of metal pipe fittings, general production enterprises is based on Building Science Research Institute developed S312, 02S404 standard atlas making. Flexible waterproof casing wall at the wall, in case of a concrete to concrete walls, and must be a solidified in the casing wall; flexible waterproof casing applied widely used in construction, chemical, steel, water, sewage treatment and other units.

Rigid waterproof casing is a steel pipe with fins ( steel ring set in the steel pipe ), installed in the wall ( for concrete wall), used for general pipe wall to wall, waterproof, and flexible waterproof casing except external wing ring, internal and retainer ring, flange, silk, have complete sets of sell, but also their own processing, is used for damping need pipeline, such as pumps and pipe wall.