2.1 Before You Begin
After unpacking the unit, check the equipment for compliance and any damage that may have occurred during shipment.
Immediately contact a Welker representative if you received damaged equipment.
When sealing fittings with PTFE tape, refer to the proper sealing instructions for the brand used.
1. A sample probe is recommended to extract sample from the center one-third (¹∕₃) of the pipeline in a location where
the product is well-mixed and will yield a representative sample.
2. For gas sampling applications, Welker recommends that the unit be installed in the top of the pipe.
3. For liquid sampling applications, Welker recommends that the unit be installed in the side of the pipe.
4. Handle the unit with care. Avoid bending and scratching the probe shaft, which has a polished surface that travels
through seals.
5. Operate the unit slowly and smoothly while inserting and retracting to avoid damaging the unit.
6. Take care not to close the pipeline isolation valve on the probe shaft while the shaft is inserted in the pipeline. This is
the most common cause of damage to Welker probes.
2.2 Preparing the AP-3 for Installation
1. Prior to installation, the length the probe shaft will need to travel inside the pipeline must be determined. Measure the
distance the shaft must travel from the top of the pipeline isolation valve to the desired insertion depth (e.g., the center
one-third (¹∕₃) of the pipeline) (Figure 5). This will be the shaft insertion length.
Figure 5: Determining Insertion Depth
2. Pull up on the probe shaft to ensure that it is fully retracted. The safety stop at the tip of the probe shaft will be flush
with the base or flange face.
3. Beginning at the top edge of the nut, measure along the probe shaft to the desired insertion length (Figure 1, Figure 2,
Figure 3, or Figure 4). Use a felt tip pen to mark this point.
SECTION 2: INSTALLATION&OPERATION
8IOM-009 MODELS: AP-3 and AP-3F REV: D 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331
