Baker Hughes Panametrics PanaFlow LC, User Manual

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Figure 95 below shows a completed odd traverse installation
without the transducers. Proceed to the section on mounting
the transducers later in this chapter.
Figure 95: A odd traverse clamping fixture installation without
transducers
B.2 Using the General Clamping
Fixture - GCF
The General Clamping Fixture (GCF) acts as a permanent
transducer holder. The fixture has two blocks (see Figure
96 below) that are used for both even-traverse and odd
number of-traverse methods. Steel straps secure the
blocks to the pipe for a permanent installation. To install the
GCF, the blocks must first be positioned using the spacing
dimension (S) calculated by the flowmeter. Then, the
transducers are mounted into the blocks.
Figure 96: General clamping fixture block
Proceed to the appropriate section for instructions on either
the even-traverse or odd number of-traverse method.
B.2.1 Even traverse method
Note: The instructions in this section can also be used for a
multiple-traverse method. However, you must use an EVEN
number of traverses. The distance the signal travels from
one side of the pipe wall to the opposite side of the pipe wall
is considered one traverse. For installations with more than
two traverses, contact Panametrics for assistance.
There are two advantages to using the even number of-
traverse method:
• Measurement accuracy is improved because the
ultrasonic signal is in the fluid longer than with a odd
number of-traverse method.
• If there is enough pipe length available, the even-
traverse fixture is easier to install.
The procedure for mounting the GCF involves setting the
transducer spacing and fastening the fixture on the pipe.
The installation procedure for transducers using the even
number of-traverse method is as follows:
1. Ensure the location of your clamping fixture has been
properly scoped out following the criteria in Section 2.6:
Precautions.
2. Prepare the pipe where you intend to place the
clamping fixture by making sure it is clean and free of
loose material. Sanding, though usually not required,
may be necessary to remove any high spots. However,
be careful to preserve the original curvature of the pipe.
3. Use a level to find the top of the pipe and then draw a
line parallel to the centerline of the pipe.
Figure 97: GCF even traverse installation, step 3
4. Using a level and center punch, make two marks on the
line drawn in step 3. These marks must be separated by
the transducer spacing distance S, as calculated by the
flowmeter.
Figure 98: GCF even traverse installation, step 4
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