Avoiding Tensions In Pipe Connections - Grundfos iGRID Montage- Und Betriebsanleitung

5.1.1 Connection of district heating pipes
WARNING
Steam
Death or serious personal injury
‐
Avoid tension in the pipe connections to
the solution and minimise thermal stress.
WARNING
Steam
Death or serious personal injury
‐
Make sure that the welding is carried out without
tension in the pipe connections.
‐
Make sure that the welded connections are carried out
according to the pipe manufacturer's instructions.

5.1.1.1 Avoiding tensions in pipe connections

WARNING
Pressurised system
Death or serious personal injury
‐
Make sure that the installation of the external pipe
connections is done according to the pipe
manufacturer's guidelines for installation to avoid
excessive stress in the pipes. Grundfos recommends
to make 90 degree bends near the inside of
the solution to avoid axial stresses.
The pipe sections between the isolating valves must not be
removed due to tension in the pipes. See pos. 2 in the
figure Avoiding tension in pipe connections to the pit.
1 2 3
4 5
Avoiding tension in pipe connections to the pit
Pos. Description
1 Existing return pipe
2 Existing supply pipe without flow
3 New supply pipe, low temperature
4 New supply pipe, high temperature
5 Temperature Zone
Compact the backfill around the pit up to the lower part of the pipe
connection before connecting the pipes.
Before connecting the pipes, check the following:
• The pipes must be clean and protected with plastic plugs.
• The inlet pipes must be properly aligned in relation to the pipe
connections.
The connection of district heating pipes must be carried
out by qualified persons. The connection must be done
according to local technical regulations from the local
utility company and according to instructions from the
supplier of the district heating pipes.
5.1.2 Supporting the pipe connection to the grid
Incorrectly performed work in connection with the support of the
district heating pipes in and out of the pit can lead to enormous
loads on the components in the pit. Large damage can occur and
lead to leakage of district heating water in the pit.
2
1
KG
Avoiding stresses on pipes which can cause serious leaks, in
straight pipe layout
2
1
KG
Avoiding stresses on pipes which can cause serious leaks, in
layout with pipe bends
Pos.
1
2
2
1
KG
Description
Stresses/loads on pipes
Damaged components in the pit
11