LPG – Liquefied Petroleum Gas – (Autogas) which often constitute of Propane (C3), Butane (C4) or propane/butane mixtures (C3/C4 or P-B mix) have ideal properties as a fuel and are widely used throughout the world. They are stable with a high-energy content and relatively low sulfur. These clean burning fuels can be transported economically in liquid form and can be consumed as either a liquid or a gas. The same distribution equipment, rail/truck tanks and storage vessels can be used for propane or P-B mixtures (in different proportions of propane and butane content depending on the season & request) so it is not outwardly apparent what grade of LPG is being used in any region or application. Combining large international supply strength with local proactive service enables regular supplies of P-B mix meeting the European Standard EN 589; ASTM D 1835 and GPA 2140 specifications from world-wide known refineries to downstream clients.
Gas in LPG tanks is LPG liquid under pressure, from 0 kPa at -42°C to 1794 kPa at 54°C, and turns back into gas when you release some of the pressure. The LPG (propane) exists as both liquid and vapour (gas) within the cylinder. See image below.