Abstract: A flow meter includes a transparent tubular housing in which an indicator in the form of a piston having a radially expanded edge cooperates with a tapered inner peripheral wall portion of the housing. The housing can include scale indicia of flow rates coinciding with positions of the indicator edge. In addition, a temperature sensitive label providing a visible indication of fluid temperature can be orthogonally aligned with respect to the flow rate scale to permit accurate placement of a graphic overlay exhibiting representations of a different fluid characteristic which varies with changes in the flow rate and temperature of the fluid within the ranges indicated by the meter. Projection of the temperature indication to the indicator edge identifies a particular value for the fluid characteristic shown on the graphic representation by mere observation.

Abstract: A bypass valve assembly is disclosed for use with a fluid flow meter of the type having a housing, an inlet, an outlet, a fluid passage which fluidly connects the inlet to the outlet and a flow rate responsive member within the fluid passage. The bypass valve assembly comprises a tubular body open at one end in which is secured to the flow meter housing so that the open end of the tube registers with the flow meter inlet. A valve member is contained within the tube and is urged to a closed position by a helical spring. In its closed position, the valve member directs all of the influent to the flow meter through the passage. When the fluid flow rate into the flow meter exceeds a predetermined amount, the valve member moves to an open position against the force of the helical spring thus bypassing the influent directly to the flow meter outlet.

Abstract: A bidirectional fluid flow indicator comprising a housing having a fluid inlet and fluid outlet, first and second separated fluid passageways intermediate said inlet and said outlet, a vane pivotally secured across one of said first channel, a second vane pivotally secured across the opposite end of said second channel, an indicator secured to said vanes for rotation therewith whereby said flow meter indicates the fluid is flowing from said inlet toward said outlet when said second vane is displaced and indicates fluid flow from said outlet toward said inlet when said first vane is pivotally displaced by the fluid flow.

Abstract: A tamper-proof cover for a fluid flow monitor comprises a guard portion at least partly disposed about the monitor when the cover sealingly engages the fluid system in which the monitor is disposed. Preferably, the cover comprises an assembly including a plate fixed to the cover of the flow monitor to seal the interior of the device. Access to the monitor and alarm or actuator circuits disposed therein is impeded by the assembly so long as the cover seals the fluid system, and access thereto requires breaching the fluid system by removing the cover.