The pressure of LPG (propane) goes from 152 kPa (24 PSIGor 1.5 bar) at 0ºC to 2482 kPa (360 PSIG or 24.8 bar) at 70ºC. The LPG – propane – exists as both liquid and vapour (gas) within the cylinder hence the pressure required to liquify petroleum gas is 152 kPa (24 PSIGor 1.5 bar) at 0ºC to 2482 kPa (360 PSIG or 24.8 bar) at 70ºC .