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

4.3.2 Joints
As in virtually all trenchless installation techniques, so with the burst lining technique
too, there are quite high forces which are applied to the joints between the pipes and
to the bodies of the pipes. The obvious course is therefore to opt for the joint which, of
all the current pipe materials, is the one which has the highest permitted tractive forces,
namely the BLS ® restrained joint (see Fig. 2.19 on page 22). Where this is particularly
important is in highly compacted and rocky soils because it is precisely in these that
very high tractive forces may occur. The permitted tractive forces for the BLS ® joint
can be seen from DVGW Arbeitsblatt GW 323 or from Table 2.1 on page 20. A rule
that applies generally is that on-line measurements must be made and documented to
ensure that the maximum permitted tractive forces are being observed. It must be remembered
in this case that the permitted tractive forces have to be reduced for plastic
pipes as a function of their temperature and of time.
4.4 To sum up
Ductile cast iron pipes with a cement mortar coating and BLS ® joints are outstanding
well suited to the burst lining technique. The principal factors are the particularly high
loads the BLS ® joint is able to carry and the extremely highly resistant cement mortar
coating, which means that you can be sure of getting a pipeline which will be both safe
and reliable in the long term. Table .1 shows a selection of pipelines that have already
been installed by <strong>Buderus</strong> using the burst lining technique.
Installations
Nominal size
DN
Length
[m]
Year
Erfurt 1 0 12 2001
Gladenbach -
1 0 700 200
Erdhausen
100 0 200
Bad Laasphe 100 00 200
200 00 2007
Ober Rabenstein 2 0 3000 200 /07
Zittau 200 00 2007
Siegen 1 0 2 0 2007
Pipeline materials
Table 4.1 Excerpt from the list of reference installations made by the burst lining technique using
<strong>Buderus</strong> Giesserei Wetzlar GmbH ductile cast iron pipes
1