Influence of Metering Valve Design on Efficiency of Unstable Gas Condensate Analysis

When unstable gas condensate is analyzed using direct sample injection into a chromatograph, the design features and operating parameters of the metering valve significantly affect the accuracy and reproducibility of the analysis. In this work, a study was made of the influence of the characteristics of two types of metering valves, namely, high-pressure and high-temperature sample metering device and sample metering valve with a syringeless injector, on unstable gas condensate analysis [conforming to GSO (State Object Standard) 10525-2014] when the sample is injected into the chromatograph without its degassing, It is shown that use of a metering valve with a heated stem helps get high metrological characteristics. Significant deviation of analysis results from the regulatory requirements was observed for hydrocarbons starting with C-28 when a metering valve having an injector was used without heating the stem.