Standard Fuel Gas Train

Conditioning and regulating the natural gas prior to admission into the engine is a critical part of the GTI Bi-Fuel system. The system `gas train` includes a 50-micron fuel filter, a manual shutoff valve, an electrically operated solenoid valve actuated in the event of an emergency or for system shutdown, and a zero-pressure, demand-type gas pressure regulator. This latter component reduces the inlet gas pressure (.5–4 psig) to roughly atmospheric pressure. With a negative outlet pressure, the design allows the system to use a `demand` control scheme whereby engine intake airflow determines the gas flow of the engine. As engine load changes, corresponding changes in intake air volume automatically draw additional fuel into the mixer.