PREMANT district heating pipe
Elbow pipe
Elbow pipes are plastic casing pipes made to customer specifications and pre-insulated at the factory. Elbow pipes
are produced as curved plastic casing pipes with a large radius and serve to optimise pipe routing when the direction
changes.
Elbow pipes behave in the same way as straight pipes; in other words, heat expansion does not cause any bending
moment. The deflection angle "a" of the pipe routing or the bend radius "R" must be known in order to produce elbow
pipes. All elbow pipes have straight ends between 1.2 and 2.0 m due to machine-based production.
The PUR foam is subject to lateral pressure as a consequence of heat expansion and the curve of the pipe. The magnitu-
de of this pressure must not exceed the permissible force of 0.15 MPa. The outcome of this is a maximum permissible
deflection angle "a" or a minimum bend radius "R".
The permissible values are contained in the following table.
PRE 6.304
Deflection angle for elbow pipes
Nominal
width
DN
40
50
65
80
100
125
150
200
250*
300**
350**
Deflection angle
bar 12 m
a min. [°]
10
8
5
4
4
3
3
3
3
3
3
perm. radius
a max.
42
38
36
34
33
29
24
20
18
11
10
perm. radius
R min. [m]
16.4
18.1
19.1
20.2
20.8
23.7
28.6
34.4
38.2
62.5
69.0
*
** DS1
DS1 and DS2 only
only
23.5.2023 BGP
Subject to technical changes
