Several methods use the Gas chromatography technique for determining the composition of liquefied petroleum gas (LPG) after a sample expansion. The LPG vaporization is often source of errors and bias. Obtain a representative vapor sample from a pressurized liquefied gas is challenging and difficult to handling. Many procedures are used in laboratories to quantitatively expand LPG samples from a liquid phase to a homogeneous gas phase prior to analysis. Most of them are off-line methods, not safe for operators and environment, user-sensitive, causing lack of reproducibility and repeatability on analysis results. SRA Instruments developed an automated and user-independent LPG Vaporizer to handle under control the critical step of LPG phase change. The heart of MyVap system is the accurate control of the expansion pressure and temperature in a heated reservoir. The vaporization cycle can be programmed easily by the MyVap. Before injection, the vapor is delivered to the GC at a selected pressure.