Patent ID: 6874374

Claim:
A flowmeter for measuring the flow rate of a fluid flowing through a conduit having an inside diameter, the flowmeter comprising: a housing conduit for location within a portion of the conduit, the housing conduit having a generally cylindrical inner surface and an outer surface, said housing conduit having an outside diameter less than an inside diameter of the portion of the conduit; locating means for locating the housing conduit within the conduit to provide sealing engagement between the housing conduit and the conduit; flow restriction means disposed within the housing conduit to create a flow restriction zone at a portion of the housing conduit to provide a restriction to fluid flow through said housing conduit, said flow restriction means comprising a generally cylindrical insert having a leading end on which fluid flowing through the housing conduit impinges, said leading end being coupled to a body of substantially constant diameter, the diameter of the leading end being less than the diameter of the body of the insert such that an annular flow path is created around said insert, and pressure measurement means disposed in the housing conduit for measuring pressure of the fluid at least at two spaced pressure measurement locations along the length of the housing conduit to measure a pressure at a first unrestricted flow location and at a second location within the flow restriction zone, said housing conduit having predetermined internal diameters at the first and second pressure measuring locations, wherein said second pressure measurement location is in said cylindrical insert body at said substantially constant diameter to measure pressure within said flow restriction zone.