Problems with sampling liquefied petroleum gas in winter
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This post was last edited by Cultivator on 2011-10-9 at 18:42. When sampling liquefied petroleum gas in winter, both gas and liquid phases are often present in the same sampling bag; this inevitably leads to poor repeatability in analysis. How do you address this issue?
Sampling from the steel cylinder; the steel cylinder and the chromatography inlet wire were kept at 150 degrees Celsius for thermal insulation, while the chromatography injection valve was kept at 200 degrees Celsius. Injection and analysis were carried out, with good parallelism.
Is that how you do it? Is a six-way valve used for the sample injection valve? Automatic? How is the injection valve insulated? At 200 degrees, can one’s hand still touch the injection valve when injecting? At 200 degrees, will the sample vaporize prematurely?
The sampling port is usually insulated in winter. If gas-liquid separation occurs after sampling with a sampling cylinder or bag and sending the sample for analysis, external insulation (or heating) can be applied; generally, a high temperature is not required as it can be tolerated.
This is a great question that deserves discussion and exploration.
It's better to take samples from the steel cylinder. As long as it is in the gas phase and uniform. It’s fine without heating.