On the first pic. , bottom right hand side is the vapourizer , with inlet lpg solenoid valve mounted on the left. On a single point closed loop system such as mine there are three hoses coming off it . Hot water in and out , and one gas hose going to the injector ring which as mentioned is mounted just before the plenum chamber . There is also a stepper motor to control the air/fuel mixture mounted in the gas hose between the vaporizer and the injector ring . check out the following link ; Go LPG - Which type of LPG conversion do you need? . With a multi-point system the gas is injected at the inlet manifold .