Patent ID: 6910673

Claim:
An improved valve having: (a) a valve body, said valve body having an inlet port and an outlet port; (b) a ball having a first axis and being interposed whiting said valve body between said inlet port and said outlet port, said ball having a first bore therethrough transverse to said, first axis ball being mounted for rotation about said first axis between a closed position, in which said inlet port and said outlet port are not in communication through said first bore, and an open position in which said inlet port and said outlet port are in communication through said first bore; wherein the improvement comprises a calibrated flow insert secured within one of said ports, said insert being substantially cylindrically symmetric about a second axis and having an orifice therethrough in substantial axial alignment with said second axis, said insert being mounted within said valve body such that said orifice is in substantial alignment with said first bore when said ball is in said opened position; and in which: said inlet port has an volume flow rate Q; said inlet port is fed by upstream piping having an inner diameter of D i ; a fluid flowing from said upstream piping through said inlet port and through said orifice of said insert has a kinematic viscosity ν; said fluid flowing through upstream piping has a first Reynolds number Re Di defined by the equation: Re Di = 4 ⁢ Q π ⁢ ⁢ D i ⁢ v said fluid flowing through said orifice of said insert has a second Reynolds number Re do that is a certain function of said first Reynolds number Re Di with said certain function being specified by a best fit curve graphed in FIGS. 6 , 7 , and 8 for said inner diameter D i ; and said orifice of said insert has a diameter d o determined using the formula: d o = 4 ⁢ ⁢ Q π ⁢ ⁢ Re do ⁢ v .