Patent ID: 8701497

Claim:
Apparatus for measuring a differential pressure of a fluid flowing through a fluid line having an upstream line connection and a downstream line connection, the apparatus comprising: a nozzle having a nozzle inlet end fluidly communicating with the upstream line connection and a nozzle outlet end, the nozzle including a nozzle interior wall defining a nozzle chamber extending from the nozzle inlet end to the nozzle outlet end, the nozzle interior wall having a nozzle inlet cross-sectional area at the nozzle inlet end that is greater than a nozzle outlet cross-sectional area at the nozzle outlet end, the nozzle interior wall tapering from the nozzle inlet end to the nozzle outlet end at a constant rate of area reduction; a differential pipe having a pipe inlet end coupled to the nozzle and a pipe outlet end fluidly communicating with the downstream line connection, the differential pipe having a pipe interior wall defining a differential chamber fluidly communicating with the nozzle chamber; a first pressure port formed in the nozzle and fluidly communicating with the nozzle chamber to obtain a first gauge pressure of the fluid; and a second pressure port formed in the differential pipe and fluidly communicating with the differential chamber to obtain a second gauge pressure of the fluid.