Hercules is a mono-phase reducer, equipped with water heat exchanger, exit pressure compensation device and temperature and pressure sensors. Compensation permits the pressure change between the reducer exit gas and the suction manifold to be maintained at a constant level, in accordance with the variations in operating conditions. this involves an increase of the injection pressure in proportion with the engine load., guaranteeing an optimal result from the system for all power requirements . The purpose of the temperature and sensor pressures is to collect the main information regarding the physical state of the LPG and to transmit it to control unit which then makes appropriate modifications to the injection times.