Abstract: A mass rate flow meter is provided having a universally-mounted gyroscopic apparatus against which a fluid stream, the mass rate of flow of which is to be measured, is directed. The fluid drives the rotor of the gyroscopic apparatus at and angular velocity proportional to the fluid stream velocity and impinges upon a pressure pad mounted on the gyroscopic apparatus, such that the effective impingement force is applied asymmetrically to the rotor, thereby applying a torque to the gyroscopic apparatus proportional to the dynamic pressure of the fluid stream and causing precessional rotation of the gyroscopic apparatus. The resulting precessional rotation of the gyroscopic apparatus is at a rate proportional to the mass rate of flow of the fluid. Measurement of the precessional rotation of the gyroscopic apparatus provides an indication of the mass rate of flow, and totalization of the precessional rotations provides total mass flow indications.

Abstract: A compound meter assembly is provided having primary and secondary passageways housing a high flow rate meter and a low flow rate meter, respectively. A flow responsive first valve is disposed within the secondary passageway and moves to a substantially closed position when the liquid flow is increasing through the secondary passageway and exceeds a first predetermined rate. Upon substantial closing of the first valve the liquid flow is diverted from the secondary passageway to the primary passageway. A pressure responsive second valve is disposed within the primary passageway and is held in a closed position with respect to the primary passageway while the pressure drop is below a first predetermined amount across the meter. The second valve is forced to an open position when a substantial pressure impulse is momentarily exerted on the second valve. The pressure impulse is created when the liquid flow is diverted from the secondary passageway by substantial closing of the first valve.

Abstract: To minimize loss of pressure energy in metering fluid flow by means of primary flow tube elements, the contour of the throat inlet section of the flow tube is that which produces a constant rate of acceleration of flow through the inlet to the throat section. The contour equation is given. At least in larger sizes of flow tubes, the inlet section is formed of thin metal such as stainless steel and arranged in such a way that it is not subject to mechanical stress in the installed assembly.

Abstract: A compound meter assembly is provided having primary and secondary passageways housing a high flow rate meter and a low flow rate meter, respectively. A flow responsive first valve is disposed within the secondary passageway and moves to a substantially closed position when the liquid flow is increasing through the secondary passageway and exceeds a first predetermined rate. Upon substantial closing of the first valve the liquid flow is diverted from the secondary passageway to the primary passageway. A pressure responsive second valve is disposed within the primary passageway and is held in a closed position with respect to the primary passageway while the pressure drop is below a first predetermined amount across the meter. The second valve is forced to an open position when a substantial pressure impulse is momentarily exerted on the second valve. The pressure impulse is created when the liquid flow is diverted from the secondary passageway by substantial closing of the first valve.