Two-Phase Sample System Introduction
When extracting a gas sample from a source that is a complex fluid mixture, such as Natural Gas, entrained liquid at source conditions with a membrane tipped probe eliminates changes in temperature and/or pressure that alter the VLE (Vapor Liquid Equilibrium) and distort the sample composition.
Extracting a sample from a two-phase source is beyond the scope of API 14.1 and GPA 2166 but these industry standards allow the use of membrane tipped probes. If source conditions are two-phase and near the dew point, then membrane tipped probes work very well, but for two-phase conditions are far from the dew point the amount of liquid could be excessive enough to overwhelm a membrane tipped probe.
The Two-Phase Sample System is used in applications where the source contains excessive liquid that would overwhelm a membrane tipped probe, and where Bureau of Land Management (BLM¹) compliance is required. It includes a specially designed probe and passageways in conjunction with a liquid vaporizing system inside an insulated enclosure that mounts onto the sample tap.
BLM¹ proposed Order 5 3175.112 (c) (4) states, “the use of
membranes, screens,or filters at any point in the sample probe is prohibited.”
Liquid Sampling Vaporization System Component Breakdown
Genie Slice Probe™
The patented probe has a sample extraction entry point that faces upstream instead of the downward facing sample entry point of conventional probes. This coupled with small passageways, prevents phase disassociation before the sample is vaporized. Once the sample is vaporized, it can be transported to the analyzer like a conventional Natural Gas sample.
Genie® Heated Regulators™
Model GHR™ and 901-GR™ heated regulators are designed specifically for analytical service. The liquid portion of a two-phase sample can typically be vaporized by pressure reduction and heat transfer with the Model GHR™, but the higher wattage and precise control of the 901-GR™ is available if necessary.
This insulated sample system case allows the sample pressure and enclosure temperature to be monitored at a quick glance, without having to remove the enclosure. For complete access to system components, one or both sides can be completely removed.
GHR: 80W @110/220 VAC or 25W @ 24 VDC
901-GR: 200W @110 VAC or 700 W @ 240 VAC
Electrical Connection Approval: CSA: Class 1, Division 1, Group C&D, T3 ATEX/IECEx: II2G Ex db IIC T3
Sample System Product Brief ⇐ ideal for one-page printing
ACES App. Worksheet ⇐ first step to building your custom solution
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