1) The socket joint of cast iron pipe is leaking.

If it is a green lead interface, it can be re-tapped, or re-tapped after cooling the lead; If it is asbestos-cement interface, self-stressing cement mortar interface, gypsum-cement interface, etc. , you can remove the interface material and reconnect it; If the rubber ring is a flexible interface, it can be recalibrated and connected in place because the rubber ring is not positioned accurately or densely. If the rubber ring is aging or damaged, it needs to be replaced.

2) It is found that the cast iron pipe is leaking due to sand holes.

Put some lead pieces or leads in the sand holes and beat them with a round-headed hammer (fitter's hammer) so as not to leak; If the hole is slightly larger, drill a hole in the sand hole to form an internal thread, and tighten it with a plug to repair it; Huff clamp plugging method can also be used.

3) Pipe cracks of cast iron pipes leak.

Before repairing the pipe section, through holes should be drilled at both ends of the crack to prevent the crack from spreading. Rubber plates can be wrapped around the cracks, and steel plate clips can be used to repair the outside. When the big cracks that can't be repaired leak, cut off the cracked pipe section, add casing and re-fill the hole.

4) The cast iron pipe section is seriously damaged.

The entire pipeline must be replaced. When replacing, one side is connected with a socket and the other side is connected with a sleeve.