Multiple orifice flow measuring device

Abstract

A multiple orifice flow measuring device includes a housing having a central passage and a shaft passage located above and parallel to the central passage. The central passage contains a pipe adapted to be connected to a gas flow line. Mounted in the shaft passage is a shaft, on which is rotatably mounted a disk having a plurality of orifices of various diameters spaced circumferentially about the disk and selectively registerable in the flow passage of the pipe. Closely fitting around the pipe against the disk is a piston having a annular recess. A spring located in the central passage between the piston and the end of the housing opposite the disk forces the piston against the disk, thereby maintaining it in position. A lever extending from outside the housing into the piston annular recess is pivotally mounted to the housing so that when gas flow is shut off and the outside end of the lever is moved towards the disk, the end of the lever located within the annular recess pushes the piston away from the disk, compressing the spring, thereby releasing the disk for rotation to a different diameter orifice.