Regulator (evaporator) - a device whose function is to change the state of matter from liquid LPG fuel - the gas and the provision of adequate quantities of gas adapted to the current needs of the engine. There are structures having one, two or three degrees of expansion. The expansion of gas in the regulator (change of state from a liquid to a gas) requires a lot of energy - gas during the expansion lowers the temperature, which is obtained from the engine cooling system (by turning the regulator in vehicle cooling circuit).