What connection methods are there for ductile iron pipes？

There are usually three ways to connect ductile iron pipes for drainage with walls such as inspection Wells.

(1) Installation method of rigid waterproof wing ring

Weld the waterstop wing ring on the ductile iron pipe and directly cast it in one piece during the construction of the reinforced concrete wall. This method uses the least materials, but the welding of ductile iron pipes requires special welding techniques, so it must be completed in the factory and cannot be done by conventional on-site welding.

In addition, ductile iron pipes are conventionally connected by T-socket. Therefore, if the rigid waterproof wing ring installation method is adopted, the pipes must be installed first, and then, depending on the position of the pipes, inspection Wells should be cast finally. If the inspection Wells at both ends are done first and then the pipes are installed, the last section will be unable to be socketed and connected.

(2) Installation method of rigid waterproof sleeve

Cast iron sleeves (with water-stop wing rings) are set outside the ductile iron pipes. The cast iron sleeves are supplied as factory finished products (made by directly pouring molten iron with molds).

When constructing reinforced concrete walls, cast iron sleeves are directly cast in one piece. Install the pipes again. Finally, use joint sealing materials to fill the gap between the pipes and the casing. Commonly used sealing materials include oil hemp winding in the middle and asbestos cement joint filling at both ends.

This installation method requires that the length of the pipe cutting be precisely coordinated with the setting of the inspection well location; otherwise, it is easy for the pipe inside the well to be too long and need to be cut. In addition, this is a rigid connection method, and the anti-settlement performance at the interface is very poor.

(3) K-type interface flexible installation method

K-type through-wall flange sleeves (with water-stop wing rings) are set outside the ductile iron pipes. The K-type through-wall flange sleeves are supplied as factory finished products (directly cast with molten iron using molds).

The K-type through-wall flange sleeve is directly cast in one piece during the construction of reinforced concrete walls. Install the pipes again. Finally, fill the gap between the pipes and the casing with a rubber sealing ring, press it tightly with a flange cover, and fix it with bolts.