Fuel is admitted through pipe 1 to chamber 2 containing float 3, which operates needle valve 4. From the float chamber, fuel is delivered through jet 5 into the narrow part of venturi 6 where it mixes with air under pressure admitted through jet 13. The space before throttle valve 8, turning about fixed axis A, is connected to the lower end of economizer cylinder 9. The space after the throttle is connected to the top of cylinder 9, containing piston 10. When the engine is running at medium load, piston 10 is in its upper position due to the considerable difference in pressure. At high loads, the pressure drop over the throttle valve is reduced to the point where piston 10 drops to its lower position due to its dead weight and the action of spring 11. This opens economizer valve 12 by pushing its member downward, and additional fuel, required at high loads, is supplied to the spray jet.
$4232$CHP,Rg$