Sealing means

A butterfly valve comprising:

• A. a valve body, said body having a passage therethrough with a planar diverging surface in proximity to the passage;
• B. a retaining means removably affixed to said body, said retaining means having a planar diverging surface in juxtaposition to the diverging surface of said body, the surfaces forming a chamber therebetween open to the passage;
• C. a closure means pivotally positioned in the passage adapted to regulate the flow of fluid through the passage, said closure means including a peripheral land adapted to engage a sealing means;
• D. a stem means adapted to rotate said closure means;
• and,
• E. an annular sealing means positioned in the chamber including in cross section:
• 1. a rectangular flanged portion adapted to be secured between said body and said retaining means;
• 2. an integral wedge-shaped portion extending from said flanged portion and pivotal thereabout, said wedge-shaped portion having a first side adjacent said retaining ring extending from and coplanar with said flanged portion, a substantially planar second side opposite said first side extending and diverging from said flanged portion;
• and,
• 3. a base joining said first and second sides, said base adapted to cooperate with said peripheral land;
• said wedge-shaped portion extending into the chamber and passage whereby when the peripheral land engages said base and no fluid is applied to either side of said valve said wedge-shaped portion is disposed substantially equidistant from each diverging surface and when fluid flow is applied to either side of said valve, fluid pressure causes said wedge-shaped portion to pivot towards the other side urging said base into the peripheral land enhancing fluid-tight engagement therebetween.