Abstract: The invention in a preferred form contemplates a valve-like structure adapted for series-connection in a pipe or other conduit line and having a valve member which is caused, within the constraint of a rectilineal guide, to change its longitudinal position as a substantially linear function of the change of fluid-flow rate in the pipe or conduit; and an inductive device tracks the position of the valve member to produce an electrical output signal which is also a substantially linear function of the fluid-flow rate. The description includes a unidirectional embodiment (which is also a check valve for flow in the non-metering direction), and a bi-directional embodiment.

Abstract: The invention contemplates a unitary magnetically sensitive circuit element or network and a flexibly articulatable elongate assembly of a plurality of such elements or networks, with electrical interconnection of the same, such assembly being inherently suited to precision operation as a function of length, whatever the length selected for a particular application or use. In one application to liquid-depth indication within a tank, the longate assembly is merely inserted into the tube along which a float-borne permanent magnet is guided, and the magnetically sensitive element of each successive unit is actuated as the float tracks liquid level and is displaced from actuating relation with one and then to the next-adjacent one of the circuit-element units. The connection of circuit-element units is such that electrical-resistance observation from one end of the assembly provides a direct indication of the liquid level at which the float magnet is currently operative.

Abstract: The invention contemplates a unitary magnetically sensitive circuit element or network and a flexibly articulatable elongate assembly of a plurality of such elements or networks, with electrical interconnection of the same, such assembly being inherently suited to precision operation as a function of length, whatever the length selected for a particular application or use. In one application to liquid-depth indication within a tank, the longate assembly is merely inserted into the tube along which a float-borne permanent magnet is guided, and the magnetically sensitive element of each successive unit is actuated as the float tracks liquid level and is displaced from actuating relation with one and then to the next-adjacent one of the circuit-element units. The connection of circuit-element units is such that electrical-resistance observation from one end of the assembly provides a direct indication of the liquid level at which the float magnet is currently operative.

Abstract: The invention contemplates a particular body construction and assembly for a check valve or the like whereby the entire valve assembly may be readily installed as a unit within the bore of standard pipe or conduit, or a standard fitting therefor. A single circumferentially extending radially inwardly open groove in the bore of the pipe, conduit or fitting, faces a corresponding radially outwardly open groove in the valve body, and stiffly compliant circumferentially extensive retainer element such as a wire of suitable gage substantially fills these grooves to retain the inserted valve in place. The retainer element is adapted for ready removability, to enable servicing or removal of the inserted valve, and the valve body is so externally characterized as to unambiguously assure valve installation in the correct direction of desired flow.

Abstract: The invention contemplates a combined closure spring and upstop having particular application to check valves having multiple valve members. The invention is illustrated by one embodiment involving two valve members hinged on a single axis oriented diametrically of the valve-flow passage, and by another embodiment involving more than two valve members hinged on separate axes oriented tangentially of the valve-flow passage.