58
Geberit Drainage Systems
Buried drain systems
Like above ground systems, the key aspect of underground installation is the management of expansion/thermal movement.
Use of expansion sockets
In addition to the butt welded and electrofusion welded
connection, the expansion socket is an ideal connection
in underground drainage systems. Since in such systems
lower temperature differences are usually encountered
than in stacks and connector pipes, smaller length
variations can be accounted for.
For this reason in underground installations the distance
between expansion sockets can be longer.
The values calculated according to the formula
and rounded off.
Please note:
The scale found on the outer surface
of the socket does not apply in the case of underground
installations.
Insert bevelled pipe to maximum socket depth,
mark and pull back 40mm.
7.3
Managing thermal movement - Buried drain application
SL (socket length)
ID (insertion depth)
d
PL (pipe length)
PL
ID
4cm
4cm
PL
≤
SL - 0.3 d
0.006
✘
Nominal
Socket
Pipe length
Insertion
outside
length
PL (for
∆
t
depth
diameter SL
≤
30ºC)
ID
Ø (mm)
(mm)
PL (m)
(mm)
110
140
15
130
125
140
15
130
160
140
15
130
200
220
20
230
250
220
20
230
315
220
20
230
