To make injections for highly volatile liquefied hydrocarbons in gas chromatography, there are several known techniques.The simplest tools are the high pressure syringes.However, the pressure limit is not high enough to analyze light hydrocarbons such as liquefied natural gas and ethylene.The traditional methods are the use of vaporizing regulators and rotary sampling valves.During sampling, discrimination of composition would take place for the samples with wide boiling point, due to condensing of heavy components and vaporizing of light components in the transfer line.Recently, piston sampling valves became commercial available.The main problem with these is service life time at high vaporization temperature or high sample pressure.