2 . According to the construction drawings. Drawing set combined with the actual site mapping sketch to find out all the pre-buried points of the casing. Find the appropriate location according to the high geometry size marked on the water supply and drainage construction drawings, and then put the casing into the reinforcement. In the reinforcement network, if you need to install gas cut reinforcement, obtain approval from civil construction before installation, then carry out gas cutting and do a good job of casing anti-blocking. When the non-concrete wall is penetrated, it should be partially changed to concrete wall, and the pouring range should be larger than the diameter of the wing ring (D4) 200, and the casing should be poured in the wall at one time. The thickness of the concrete wall at the pipe penetration should be less than 200, otherwise the wall should be thickened on one or both sides, and the diameter of the thickened part should be at least D4+200.
3 . Rigid waterproof casing can be divided into type A and type B. Type A is applicable to steel pipes, and type B is applicable to ductile iron pipes and cast iron pipes. From a standard point of view, there are 02S404S312 and other standard atlas. In the selection or treatment of rigid waterproof casing, should meet the pipeline planning conditions and equipment requirements. If necessary, the waterproof casing should be approved by the structural engineer through the wall thickness and axial thrust. The installation direction of waterproof casing should try to avoid settlement joints, expansion joints or the interval between two structures. If there is a special need, it should be selected by the structural engineer.
