1. The appearance quality of ball-milled cast iron pipes and fittings meets the requirements: there should be no cracks on the surface of the pipes and fittings, and the pipes and fittings should not have uneven defects that hinder use; the inner working surface of the socket and the outer working surface of the socket should be smooth. It is clear and must not have defects that affect the sealing of the interface; the dimensional tolerance of the ball milled cast iron pipe should meet the current national product standards.
2. Before the pipe and pipe fittings go down the trench, the oil inside the socket should be removed. Spikes. Cast sand and uneven cast tumors; cracked pipes and pipe fittings should not be used. When installing the pipe along a straight line, the pipe diameter tolerance combination should be selected The smallest pipe joint group is connected, the circumferential gap of the interface should be uniform, and the longitudinal gap between the sockets should not be less than 3mm; when the pipeline is installed along the curve, the allowable angle of the interface should not be greater than 1°.
3. The round rubber ring should meet the requirements of the current national standard ``Pre-(self) stress. Rubber seal ring for self-stressing reinforced concrete pipes''.
4. The installation deviation of ball milled cast iron pipe meets the following regulations: axis position deviation 30mm, elevation deviation ±20mm.