A valve insert including a ring made of a resilient material. The ring has a shape that is defined by the rotation of an irregular polygon around a central axis. Superposing a quadrilateral and a circle forms the irregular polygon.
1. A valve insert, comprising:
a ring, made of a resilient material, having shape is defined by the rotation of an irregular polygon around a central axis, said irregular polygon is formed by superposing a quadrilateral and a circle wherein:
said quadrilateral is a plane figure including:
a first side being connected to a second side at a first interior angle;
a third side being connected to said second side at a second interior angle;
a fourth side being connected to said third side at a third interior angle;
said fourth side being connected to said first side at a fourth interior angle;
said first side being longer than said fourth side;
said fourth side being longer than said second side;
said second side being longer than said third side;
said first interior angle and said second interior angle both being right angles;
said third interior angle being an obtuse angle; and,
said fourth interior angle being an acute angle;
said circle is a plane figure including a center and a radius, and said radius being shorter than said third side of said quadrilateral;
said center of said circle being positioned within said quadrilateral;
said circle crossing said first side and said second side.