Method and system for orifice control of valve pressure drop

A valve tray for use in a chemical-process column, the valve tray comprising:

• a tray surface having at least one aperture formed therein, the at least one aperture having an aperture area;
• at least one fixed valve disposed on the tray surface in a spaced relationship relative to the at least one aperture, the at least one fixed valve comprising:
• a central portion being spaced from the at least one aperture and having a substantially round shape,
• a vane being formed around a circumference of the central portion, wherein the vane extends outwardly and downwardly from the central portion, wherein the vane is angled from the central portion of the valve at an angle of 11° to 79° relative to a horizontal, and wherein the vane accounts for 20% to 50% of a diameter of the valve, and
• at least one leg extending downwardly from an edge of the vane, wherein the at least one leg supports the central portion and maintains the central portion in the spaced relationship with the at least one aperture,
• the aperture area being smaller than the surface area of the valve, and
• a vertical distance of an outer edge of the vane and an uppermost point of the central portion of the fixed valve being 1.0 to 2.0-times a vertical distance of the outer edge of the vane and the tray surface.