High conductance valve for fluids and vapors
A high conductance valve for use in fluid delivery systems is comprised of a flat non-circular orifice ridge adjacent to which a control plate having a planar control surface is proximally positioned to adjust the valve effective opening area and thereby the conductance of the valve. The length of the non-circular orifice ridge periphery is substantially greater than the circumference of a similarly sized circular orifice and therefore the realized effective opening area is also substantially greater despite having a similar footprint.
1. A valve comprising: a valve body having a first fluid conduit opening; an orifice ridge disposed within the valve body and having a plurality of interconnected segments that form a non-circular closed circuit surrounding the first fluid conduit opening, the plurality of interconnected segments including a first perimeter portion that faces the first fluid conduit opening in a concave manner and a second perimeter portion, nested in the first perimeter portion, that faces the first fluid conduit opening in a convex manner; and a control plate having a substantially planar control surface, the control surface configured to be positioned above the orifice ridge, the control surface configured to contact an upper boundary face of the orifice ridge in a substantially planar state, wherein the upper boundary face of the orifice ridge is configured to be on a single plane substantially perpendicular to a movement axis of the control plate; and wherein the orifice ridge defines an inner cavity between the orifice ridge and the first fluid conduit opening, an area of the first fluid conduit opening being smaller than an area of the inner cavity.
2. The valve of claim 1 , wherein the valve body includes a second fluid conduit opening disposed external to the orifice ridge.
3. The valve of claim 1 , wherein the control plate is moveable between a first position in which the substantially planar control surface abuts the orifice ridge and a second position in which at least a portion of the substantially planar control surface is separated from the orifice ridge.