expansion joints - AR Thomson Group

Torsional Misalignment
This condition occurs when rotation of the pipe
flange causes bolt holes to be out of line (see Figure 9
for illustration). Minor torsional misalignment can be
handled using a standard expansion joint; however,
severe torsional misalignment requires an expansion
joint with the degree of torsional offset built-in (see
Appendix Table IV for limitations and Figure 9 for illustration).
As an alternative, realign the pipe flanges or drill
the expansion joint on-site. Contact the manufacturer for
tooling and instructions.
10
Figure 9
Torsional misalignment of metal flanges
9A 9B
T
Concurrent Misalignment
Special expansion joints are required for combinations
of severe lateral and angular misalignment. This
condition requires exact measurements along with the
location of the misalignment measured. To best accommodate
this situation, drawings that detail these measurements
should be provided with the order. If assistance
is required, contact the manufacturer for a survey
of the expansion joints.
When ordering offset expansion joints, they must be
properly identified with a customer equipment number.
The manufacturer must also mark the center line of the
flange face as well as the back of the joint flange. This
will ensure proper location and ease of installation.
Rubber Flange
Metal Flange
Rotation of
Metal Flange