PLATE AS. 1W6632 - Caterpillar

Illustration 1 g00742150
Gas pressure regulator
(1) Chamber
(2) Adjusting screw
(3) Spring
(4) Balance line
(5) Outlet for gas
(6) Diaphragm
(7) Chamber
(8) Lever
(9) Pivot pin
(10) Valve stem
(11) Valve
(12) Inlet for gas The fuel flow is determined by the pressure differential between the gas pressure and the air pressure. Usually, the pressure of the gas must be greater than the air pressure.To maintain an accurate adjustment of the gas pressure to the carburetor, balance line (4) is connected to the inlet of the carburetor. This causes the pressure on the air side of diaphragm (6) to be equal to the pressure in the carburetor.Spring (3) and the air pressure in chamber (1) presses on diaphragm (6). The movement operates lever (8) at pivot pin (9). The lever moves valve stem (10) and valve (11). This allows gas from inlet (12) to enter chamber (7). The valve stops opening when the gas pressure in chamber (7) under the diaphragm is equal to the force from the spring and the pressure in chamber (1). The gas exits the regulator through outlet (5).The pressure of the gas from the regulator is adjusted with screw (2). The pressure must be adjusted for the type of carburetor.As the load increases, the governor opens the throttle plate further. This reduces the pressure on the gas side of the diaphragm. The spring and the air pressure open the gas valve. The gas valve opens until the pressure under the diaphragm is balanced again with the forces of the spring and pressure from the balance line on top of the diaphragm.