In gas and oil tanks, the temperature must remain constant and therefore must be monitored permanently. Crude oil is transported at 50 °C, liquefied petroleum gas (LPG) under pressure (10 bar) at room temperature and liquefied natural gas (LNG) at around -160 °C. In order to be able to monitor the internal tank pressure at these low temperatures, the gas is heated to - 40 °C via evaporation lines to the pressure transmitter.
