Welding Process - WIKA TC59-V Betriebsanleitung

6. Commissioning, operation
6.4 Tests/Checks
Test loop resistance of the thermocouple circuit at ambient temperature prior to welding/
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routing the V-PAD
After completing the welding/routing of the V-PAD
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ambient temperature and compare.
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If a deviation of greater than 5 % between readings occurs, please contact WIKA.
Perform any non-destructive examination or heat treatment as required.
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Ensure adequate tube wall thickness at the weld locations. This can be checked by
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thickness testing to customer specifications.

6.5 Welding process

Gas Tungsten Arc Welding (GTAW) is the suggested welding process due to its relatively
clean weld. Small diameter filler rod (2.4 mm / 3/32" OD) and Tungsten (1.5 mm / 1/16",
2.4 mm / 3/32" OD) give the best penetration, especially for the root passes. During
welding operation, the requirements of the relevant material data sheets and the applicable
directives and standards must be considered regarding the heat treatment, filler rods
or welding procedures. Proper installation is a major step in the success of a V-PAD
installation. Although the V-PAD
destroyed by improper welding. WIKA can supply V-PAD
practice welding if required.
6.6 V-PAD welding
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Clamp the V-PAD
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damaging the outer surface of the V-PAD
Ensure there is good line contact with the tube (see figure 1). Avoid tilting the
V-PAD and ensure the edge makes good contact with the tube (see figure 2).
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Ensure good axial alignment with the tube axis (see figure 4). This will ensure
any differential expansion of the MI cable is smooth and does not bind with the
tube clips.
Preheat the area to be welded (including the V-PAD
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Tack weld one end of the V-PAD
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root pass. Watch for tilt, gap, line contact, etc.
Attach a thermocouple meter to the cold end of the thermocouple for measurement.
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WIKA operating instructions model TC59-V (V-PAD
, record results.
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is one of the most rugged sensors available, it can be
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(using a chain clamp!) to the appropriate location on the pipe. Avoid
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. Visually check alignment before proceeding with the
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to the tube, test loop resistance at
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test thermocouples on request for
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when clamping.
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) as appropriate for the materials.
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)
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EN
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