Elliptical Sealing Surface for Butterfly Valve

A valve having reduced seal wear and reduced friction comprising:

• a valve body having inlet and an outlet forming a passage in the valve body;
• a valve stem extending into the valve body;
• a disc rotatable by the valve stem to open and close the passage, the disc having a perimeter;
• a valve seal having an elliptical first shape with a major axis greater than a minor axis the valve seal deforming through contact with the disc as the disc rotates to a closed position to a second shape different from the first shape in which the valve seal substantially contacts the disc perimeter, thereby to substantially close the passage, wherein the valve seal is to red of a resilient material that substantially returns to the first shape when the disc subsequently moves back toward an open position;
• wherein the valve seal is a two-piece assembly including an outer surface in press-fit engagement with the valve body.

A method for minimizing valve seal wear while controlling flow of fluids comprising:

• placing a substantially circular disc in a substantially circular valve body passage to control fluid flow, the disc having a rotational axis, a disc diameter perpendicular to the rotational axis and a circumference;
• forming an elliptical valve seal in the valve body such that the valve seal does not engage the disc at the rotational axis when the passageway is open and the elliptical valve seal interferes with the disc diameter upon substantial closure of the passage;
• and
• deforming the elliptical valve seal during closure of the passage such that the elliptical valve seal engages the disc tangential to the rotational axis when the disc substantially closes the passageway thereby providing control of flowing fluids with minimum valve seal wear.

A valve having reduced seal wear and reduced friction comprising:

• a valve body having an inlet and an outlet forming a passage in the valve body;
• the valve body further including an elliptical valve seat, the elliptical valve seat having a major axis greater than a minor axis of the elliptical valve seat;
• a valve stem extending into the valve body;
• a disc rotatable by the valve stem to open ad close the passage, the disc having a sealing periphery;
• a valve seal comprising a resiliently deformable sealing ring sized to fit within the elliptical valve seat in press-fit engagement, the resiliently deformable sealing ring being deformed by engagement of the disc to the valve seal to temporarily make substantial contact with the sealing periphery of the disc when the disc substantially closes the passage ad the resiliently deformable sealing ring returning to an undeformed state when no longer in substantial contact with the scaling periphery of the disc;
• and wherein the valve seal is a two-piece assembly.