To ensure ACCURATE sampling of natural gas, the sample taken must be repeatable and representative of the product flowing in the pipeline, per GPA 2166-88.

1. A sample probe must be positioned in the center one-third of the pipe where there is positive velocity and no turbulence. Using stainless steel tubing, connect the probe to the sampler, avoiding any dips or low spots in the sample line.Mount the sampler higher than and as close to the probe as possible.

2. The composite sampler must be designed to purge from the probe tip through the sampler chamber, collect fresh sample, maintain the sample at full linepressure, and pump the collected sample into a cylinder regardless of pipeline pressure of temperature variation.

3. The sampler cylinders must be constructed of materials that is compatible with the product being sampled, approved by D.O.T. for transportation, and designed to maintain the sample phase. Installation or exchange of the sample cylinders requires that the cylinder, valves, and sample line be purged and checked for leaks before sampling is to resume.

To learn more about composite sampling of natural gas or other related products, please contact your nearest Welker representative.