These small NGL processing facilities can be located in oil fields so the butane and propane liquid under light pressure of 125 pounds per square inch ,can be shipped by rail, truck or pipeline.Propane can be used as a fuel in oil fields to heat various facilities used by the oil drillers or equipment and trucks used in the oil patch.EG: Propane will convert from a gas to liquid under light pressure under 40 PSI, give or take depending on temperature, and is pumped into cars and trucks at less than 125 PSI at retail stations. Pipelines and rail cars use about double that pressure to pump at 250 PSI. To convert PSI pressure to metric pascals multiply one PSI is 6,894.75 pascals which is the same as 2.0360 inches of mercury.