Patent ID: 7108244

Claim:
A valve arrangement for compressible fluids, comprising: a cutoff plug having a continuous peripheral concave surface of radius of curvature r q extending directly to a cutoff corner to form an end portion having a substantially circular cross section of radius r e without an intervening cyclindrical-shaped portion between the peripheral concave surface and the cutoff corner; and a seat opposite the cutoff plug having a central aperture along a central axis of the valve arrangement, with the central aperture defined at least in part by a convex surface of the seat having radius of curvature R, and with the central aperture having a throat of radius R s , wherein the cutoff plug is capable of axial displacement along the central axis and relative to the seat for opening and closing the valve arrangement, wherein the cutoff corner of the plug is defined by an intersection of the end portion and the peripheral concave surface of the cutoff plug, wherein r e is less than R s , wherein r q is greater than R, and wherein the cutoff corner defines an angle of at least about 90°.