Patent ID: 7222757

Claim:
A pressure relief device for venting an internally pressurized container comprised of: a concave annular outer area having a selected thickness of at least about 0.024 inches; a circular central area of the same selected thickness, the central area having a center point and an arc shaped score line extending through 132° to 138° about an arc center, the arc center offset from the center point of the circular area by a distance of from 0.288 to 0.292 inches, the score line being trapezoidal in transverse cross section and having a depth of from 0.010 to 0.012 inches; and an annular intermediate area of the same selected thickness connecting the concave annular area to the circular area such that the intermediate area meets the circular area at an angle greater than 90° and the intermediate area meets the concave annular outer area at an angle greater than 90°.