Abstract: Apparatus for controlling the air to gas ratio of fuel being supplied to a gas engine that utilizes the pressure in the inlet of the carburetor and the pressure in the intake manifold of the engine to control a regulator that is used to supply gas to the engine. The control mechanism is responsive to a signal from an intelligence source, such as an exhaust gas sensor, for varying the air to gas ratio to a preset or desired air to gas ratio. A method for controlling the air to gas ratio of fuel being supplied to a gas engine wherein an engine function is sensed and a signal generated representative of the function. The signal is compared with a reference signal and a resultant signal is generated. Pressure is then generated that is representative of the resultant signal and the pressure is applied to the regulator to cause a predetermined rate of flow of gas to the carburetor, thereby controlling the air to gas fuel ratio to the engine.

Abstract: The centrifugal pump is of the submersible type and is useful in pumping sand laden fluids. The pump includes a rotatable impeller and fixed diffuser and has an improved bearing that comprises an annular thrust member that is constructed from material having a hardness greater than the hardness of sand. The thrust member is attached to the impeller and has a bearing surface thereon. A second annular bearing member, which is also constructed from material having hardness greater than sand, is attached to the diffuser and has a bearing surface thereon disposed in juxtaposition with the bearing surface on the thrust member.