Constant flow valve

Claim 1

A constant flow valve comprising a tubular conduit fitting having a tubular flow restrictor fixed within said tubular conduit fitting, said flow restrictor having an inner surface which has as the generatrix thereof a curved line X--X, an inner valve mounted within said conduit fitting opposite to said flow restrictor by means of a spring, one end of said spring being held within said conduit fitting, said curved line X--X osculating with a plurality of curves, each of which is formed by: (a) applying equations in each of the positions which said inner valve holds when a plurality of the displacements thereof are L n 's, the equations being: ##EQU10## y=a+x tan Θ.sub.n ( 3) and z.sup.2 =x.sup.2 +(y-a).sup.2 ( 4), where a=the radius of the flat portion of the inner valve, F n =the required orifice area which constitutes the effective area of fluid flow through the restrictor, α=the coefficient of discharge, g=the acceleration due to gravity, k=the spring constant, A=the pressure-receiving area, γ=the specific gravity of fluid, z=the line segment (z 0 ° ˜z 90 °) which constitutes the generatrix of the lateral surface of the required truncated cone, and Θ n =the angle (0°˜90°) between the line segment and the axis of the constant flow valve; (b) drawing the line segments z's (z 0 ° ˜z 90 °) on a plane passing through the axis of said constant flow valve so that one end of each of the line segments z's is located at one of two points of intersection of the plane and the downstream edge of said inner valve, and the line segments z's make their respective angles Θ n 's (0°˜90°) with the axis of said constant flow valve and correspond in length to their respective angles Θ n 's; and (c) connecting the other ends of said line segments z's.

Claim 3

A method of accurately providing a uniform flow rate at the downstream side of a flow control valve when changes in pressure differential occur between the upstream and downstream sides of the control valve, said control valve being of the type having a fixed, tubular flow restrictor operable in conjunction with a movably biased valve member, comprising shaping said fixed flow restrictor with a surface which has as the generatrix thereof a curved line X--X, said curved line X--X osculating with a plurality of curves each of which is formed by: ##EQU11## y=a+x tan Θ.sub.n ( 3) and z.sup.2 =x.sup.2 +(y-a).sup.2 ( 4), where a=the radius of the flat portion of the inner valve, F n =the required orifice area which constitutes the effective area of fluid flow through the restrictor, α=the coefficient of discharge, g=the acceleration due to gravity, k=the spring constant, A=the pressure-receiving area, γ=the specific gravity of fluid, z=the line segment (z 0 ° ˜z 90 °) which constitutes the generatrix of the lateral surface of the required truncated cone, and Θ n =the angle (0°˜90°) between the line segment and the axis of the constant flow valve; (b) drawing the line segments z's (z 0 ° ˜z 90 °) on a plane passing through the axis of said constant flow valve so that one end of each of the line segments z's is located at one of two points of intersection of the plane and the downstream edge of said inner valve, and the line segments z's make their respective angles Θ n 's (0°˜90°) with the axis of said constant flow valve and correspond in length to their respective angles Θ n 's; and (c) connecting the other ends of said line segments z's.

Claim 4

A method of accurately providing a uniform flow rate at the downstream side of a flow control valve when changes in pressure differential occur between the upstream and downstream sides of the control valve, said control valve being of the type having a fixed, tubular flow restrictor operable in conjunction with a movably biased valve member, comprising shaping said fixed flow restrictor with a surface which has as the generatrix thereof a curved line X--X, said curved line X--X osculating with a plurality of curves each of which is formed by: ##EQU11## y=a+x tan Θ.sub.n ( 3) and z.sup.2 =x.sup.2 +(y-a).sup.2 ( 4), where a=the radius of the flat portion of the inner valve, F n =the required orifice area which constitutes the effective area of fluid flow through the restrictor, α=the coefficient of discharge, g=the acceleration due to gravity, k=the spring constant, A=the pressure-receiving area, γ=the specific gravity of fluid, z=the line segment (z 0 ° ˜z 90 °) which constitutes the generatrix of the lateral surface of the required truncated cone, and Θ n =the angle (0°˜90°) between the line segment and the axis of the constant flow valve; (b) drawing the line segments z's (z 0 ° ˜z 90 °) on a plane passing through the axis of said constant flow valve so that one end of each of the line segments z's is located at one of two points of intersection of the plane and the downstream edge of said inner valve, and the line segments z's make their respective angles Θ n 's (0°˜90°) with the axis of said constant flow valve and correspond in length to their respective angles Θ n 's; and (c) connecting the other ends of said line segments z's.