12
ULTRA-E-F
the transducers will be located. See
Figure 2.1
for acceptable radial orientations. Wrap the
template back around the pipe, placing the beginning of the paper and one corner in the
location of the mark. Move to the other side of the pipe and mark the pipe at the ends of the
crease. Measure from the end of the crease directly across the pipe from the first transducer
location) the dimension derived in Step 2, Transducer Spacing. Mark this location on the
pipe.
4.
The two marks on the pipe are now properly aligned and measured.
If access to the bottom of the pipe prohibits the wrapping of the paper around the
circumference, cut a piece of paper to these dimensions and lay it over the top of the pipe.
Length = Pipe O.D. x 1.57; width = Spacing determined on Menu 25.
Mark opposite corners of the paper on the pipe. Apply transducers to these two marks.
5.
Place a single bead of couplant, approximately 0.5 inch [15 mm] width, on the flat face of
the transducer. See
Figure 2.2
. Generally, a silicone-based grease is used as an acoustic
couplant, but any grease-like substance that is rated to not “flow” at the temperature that the
pipe may operate at, will be acceptable.
a)
Place the upstream transducer in position and secure with a stainless steel strap or other.
Straps should be placed in the arched groove on the end of the transducer. A screw is
provided
b)
Try to help hold the transducer onto the strap. Verify that the transducer is true to the pipe
- adjust as necessary. Tighten transducer strap securely. Larger pipes may require more than
one strap to reach the circumference of the pipe.
6.
Place the downstream transducer on the pipe at the calculated transducer spacing. See
Figure 2.6
. Using firm hand pressure, slowly move the transducer both towards and away
from the upstream transducer while observing Signal Strength. Clamp the transducer at the
position where the highest Signal Strength is observed. Signal Strength of between 60 and 95
percent is acceptable. On certain pipes, a slight twist to the transducer may cause signal
strength to rise to acceptable levels.
7.
Secure the transducer with a stainless steel strap or other.