Buderus Manual on Trenchless Installation of Ductile Cast ... - Duktus

Properties of ductile cast iron pipes
Fig. 2.20
When joints are being made with a hydraulic digger, a suitable interlayer, e.g. a length
of squared-off timber, must be placed between the pipe and the bucket of the digger.
The pipe must be pressed in gently and sufficiently slowly for the gasket to have time to
deform. Regardless of what equipment is selected to make the joint, pipes and fittings
must be lined up so that they are concentric and square to one another.
Locking
The pipe remains square to the socket and is pressed into the latter until the welding
bead is resting against the internal locating bead. This ensures that there is room for the
locking members. Depending on how many there are, these are inserted though the
openings in the end-face of the socket and are distributed around the circumference
to the right and left. In the size range from DN 80 to DN 00 the locking members
are locks (Fig. 2.21) whereas in the range from DN 00 to DN 1000 they are segments
of a flat, planar form (Fig. 2.22). In the case of the locks, a distinction has to be made
between the „left“ and right“ types, and these have to be inserted as directed in the
installation instructions. With trenchless installation techniques and in high-pressure
applications, an additional high-pressure lock is required. When the fitting of the locking
members has been completed, a rubber catch fitted in the opening that is still clear
in the end-face of the socket stops the locking members from shifting.
2
Wrong
Right