NOZZLE AS-FUEL VALVE 1N4668 - Caterpillar

Illustration 1 g00830515
Diagram for a turbocharged air inlet and exhaust system with low pressure gas (AA) Exhaust gas (BB) Air and gas to cylinders (CC) Gas supply (DD) Low pressure gas (EE) Air inlet (1) Gas pressure regulator (2) Balance line (3) Carburetor (4) Air cleaner (5) Turbocharger (6) Gas supply (7) Governor actuator (8) Aftercooler (9) Air inlet manifold (10) Cylinder (11) Exhaust bypass valve (12) Exhaust manifoldNote: The customer is responsible for supplying clean, dry fuel to the engine. A proper fuel filter removes impurities that can damage the internal components of the engine. Fuel filters are usually a provision of the design for the site. Caterpillar does not include a standard fuel filter as part of each gas engine. However, fuel filters are available from your Caterpillar dealer.Fuel from gas supply (6) goes to gas pressure regulator (1). After the gas is reduced to the desired pressure by the regulator, the gas goes to carburetor (3) .Inlet air is filtered by air cleaner (4). The inlet air pressure is delivered to the gas pressure regulator through balance line (2). This enables the regulator to maintain the differential pressure between the gas and the inlet air.The air and the fuel are mixed in carburetor (3) and the mixture is compressed by turbocharger (5) .Governor actuator (7) controls the opening of the throttle. The air and fuel is cooled in aftercooler (8) before entering air inlet manifold (9) and cylinders (10) .Exhaust gas travels to exhaust manifold (12). Some of the exhaust gas drives turbocharger (5) before the exhaust gas exits through the exhaust outlet. If the boost pressure is excessive, some of the exhaust gas is diverted by exhaust bypass valve (11) to the exhaust outlet.A gas shutoff valve is required in the supply line. This valve may be electrically operated from the ignition system. The valve can be operated manually in order to stop the engine. Manual resetting of the valve is needed in order to restart the engine.Engine installations that use dual fuel systems have components that are similar to the components in the above illustrations. However, an engine that uses a dual fuel system requires two gas pressure regulators. When the gas is changed, adjustments must be made for differences in the BTU content of the gas. If the appropriate controls are installed, an engine that has a dual fuel system can change fuels automatically. For optimum operation, the engine timing must be adjusted when the fuel is switched.