Page 122 - RACI

13 seleCtION gUIDe

Hdpe spacers

Ring Modular element of the ring

Double Ring Socket joint Jacket pipe
at each end

cHOice Of eleMent HeigHt (H) O.db. h
project data to be considered: O.d. I.d.
socket
• exact outside diameter of the main pipe including the joint
protective coating O.d.

• exact inner pipe diameter of casing pipe i.d.

• exact outer diameter of the joint or flange O.db.

the maximum height of the element to be adopted
is given by the following comparison:

[ O.d. main pipe ] + [ ]2 x H element’s height + [ tolerance 12 ÷15 mm ] < [ i.d. jacket pipe ]

Whenever the main pipe has socket or flanged joints,
consider a second factor, so as to allow the element to
exceed the height of the coupling:

[ O.d. main pipe ] + [ 2 x H element’s ]height > [ O.db. socket pipe + tolerance min. 20 mm]

in this case the rings will be installed upstream and
downstream of joint, at a distance not exceeding 30cm.

calculatiOn Of tHe nuMBer
Of eleMents fOr a crOssing

It is recommended to insert a double ring at the ends of
the pipe to avoid problems during inserting operations and
to duly distribute the overcharge.

the exact number of rings is then derived from the
following formula:

tot = l / i + 3

the total number of elements for a crossing is:
tot = x
Heavy duty applicatiOns
tot rings necessary
For longer crossings ( >150 m) or very heavy pipes, l crossing length
it is possible to increase the frequency of the rings
or to use special reinforced elements. i recommended spacing
(see dedicated table of the selected element)
the reinforced elements are designed with
increased sacrificial thickness. However, for heavy elements to make a ring
applications or non-standard applications, (see specific table of the selected element)
a more detailed analysis is required to consider
the particular conditions of the construction site.
In these cases, we recommend a consultation with
RaCI for the necessary technical support.

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