US Patent 10018290 Pressing ring, joint, and valve

A first projection is formed on the outer periphery of a bulb part, a second projection is formed on the socket rear end of the bulb part, a tapered part is formed with a decreasing diameter from the inner periphery of a heel part to the inner periphery of the second projection, and a third projection is formed on the tapered part. A first dimension B from the first projection to the third projection in an inclination direction opposite to an inclination direction G of the tapered part is smaller than a second dimension C from the first projection to the second projection in a radial direction A.