In the sampling of light liquid hydrocarbons, the liquid state of the sample must be maintained at all times. To accomplished this, the following equipment and operating features should be employed:

1. A probe (appropriately designed) should be used to gather the sample from the center one-third of the flowing stream. The probe location should be where the product is flowing and homogenous and away from bends, obstructions and excessive turbulence.

2. A bypass stream passing through the sampler must be provided with the temperature maintained within 1 °F of the flowing stream. This can be accomplished with a drive plate, pump, controlled bypass around a control valve, pitot prolate, or other appropriate pressure drop.

3. The sampler should be capable of pumping the trapped sample into the collection cylinder indepenent of pipeline pressure, temperature or sample cylinder pressure. Timing of the sampler should be proportional of the flow when possible.

4. The sample collection cylinder must be capable of maintaining the product in the liquid state under all conditions and be constructed of materials that will not absorb the product components. The cylinder must have a non-penetrable harrier between the source of constant pressure used to maintain product in its liquid state.

5. An effective sample mixer should be used on the collection cylinder to break up stratification. Stratification may occur by day and by product.

6. A transportation cylinder must also be provided that will maintain the sample in the liquid state when it is being transported to the lab.

7. During lab analysis, the liquid integrity of the product must be maintained. Mixing may be required in some cases during injection into the chromatograph.

To learn more about light liquid hydrocarbon sampling or other related products, please contact your nearest Welker representative.