5.2.2 Cold Tapping
Installation of transducer holders must always be supervised by trained Fluenta personnel.
Before installing the transducer holders on the pipe, the correct placement of the spot marks
must be ensured. There are numerous ways this can be done.
The first consideration is the location of where the spot marks are supposed to be placed.
Figure 5 shows that the horizontal distance between spot A and spot B is the same as the
outer diameter of the pipe (applies only to 45° installations).
Figure 5: Cold tapping – placement of spot marks.
The first thing to do is to find the centerlines on the pipe. Note that the centerlines are exactly
opposite each other on the pipe, ref. Figure 6. Always ensure that the centerlines are placed
accurately by measuring the distance between them, both on the upper and lower
circumference. The measured lengths should be the same.
If the pipe is horizontal, use the Curv-O-Mark contour marker to find the centerlines on each
side of the pipe, ref. Figure 7. Remember to turn the contour marker and set a second spot,
to avoid problems in regards to misalignment of the grade scale.
If the pipe is vertical or inclined at a certain angle, other means of finding the centerlines
must be applied. Confer with the pipe fitter or welder, as they usually have the tools and
experience needed to help you.
One proven method is to use a marking band. After the centerlines have been marked and
their position has been verified, use the labeling band to mark a line around the pipe, placed
at the first spot (spot A), ref. Figure 8. Then, on the other side of the pipe, measure the
distance to the second spot (spot B). It is also a good idea to mark another line around the
pipe at spot B, as this will help when placing transducer holder B.
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