Patent ID: 7357040

Claim:
A flow meter for measuring the volume of fluid flowing through the meter comprising: an inner cylindrical tube through which the fluid flows; an outer cylindrical tube tending over the inner cylindrical tube and radially spaced from the cylindrical inner tube to provide an annular cylindrical space between the inner cylindrical tube and the outer cylindrical tube; a seal between the inner cylindrical and the outer cylindrical tube closing the annular cylindrical space adjacent ends of the annular cylindrical space with the pressure in the inner cylindrical tube; a flow restriction member integrally formed within an inner wall of the inner cylindrical tube, the flow restriction member being defined by two opposing wedge members adjoined at a circular vertex having a smaller diameter than the inner cylindrical tube, the circular vertex for restricting the flow of fluid through the inner cylindrical tube and producing a pressure drop in the fluid as it flows through the circular vertex; the inner cylindrical tube and the outer cylindrical tube in combination further define at least two ports for receiving a pressure sensing device to measure the pressure of the fluid through the flow meter, wherein at least a first of the ports is positioned at an upstream area of the flow meter from the circular vertex, and at least a second of the ports is positioned at a downstream area from the circular vertex; the outer cylindrical tube has a first flange at a first end thereof, a recess defined within the flange, and at least two alignments pins extending from a surface of the recess; and the inner cylindrical tube has a second flange at a first end thereof, the second flange abutting the first flange within the recess and further having holes receiving the alignment pins therein for centering the inner cylindrical tube within the outer cylindrical tube.