I work a lot with natural gas in both gas and liquid form, there were some questions on how it stays in each form.
The (gas) natural gas is transported via pipelines, with pressures varying between 400 and 2500 PSI. Gasses will not change state unless the pressures are appropriate and you either provide or take away the latent heat of vaporization by heating or chilling. So in essence it behaves just like the AC in your car. Methane, which is the most common component in NG, will not liquify until it it dropped to -250F, and will remain there at almost no pressure, less than a PSI until you give it enough energy to change back to gas, where it expands about 900 times. The LNG systems use the heavies, i.e. propane, pentane and hexane as refrigerants to cool the methane so it will condense, they then use natural gas in heaters to vaporize it and put back on the line.
The (gas) natural gas is transported via pipelines, with pressures varying between 400 and 2500 PSI. Gasses will not change state unless the pressures are appropriate and you either provide or take away the latent heat of vaporization by heating or chilling. So in essence it behaves just like the AC in your car. Methane, which is the most common component in NG, will not liquify until it it dropped to -250F, and will remain there at almost no pressure, less than a PSI until you give it enough energy to change back to gas, where it expands about 900 times. The LNG systems use the heavies, i.e. propane, pentane and hexane as refrigerants to cool the methane so it will condense, they then use natural gas in heaters to vaporize it and put back on the line.