Abstract: In manufacturing a tubular valve sleeve having axially extending grooves on its inner surface, the valve sleeve groove ends are closed by radially inward displacement of sleeve material, which is limited by a mandrel to minimize the formation of cracks in the material. First, a tubular member is provided which has a plurality of grooves extending axially along an inner surface of the tubular member through the axially opposite end surfaces of the tubular member. The end surfaces extend radially outward from the inner surface of the tubular member to the outer surface. Each of the axially extending grooves has a base surface located between the inner and outer surfaces. A pair of first punches are simultaneously forcefully abutted against the end surfaces, between the base surface of each groove and the outer surface. This displaces material of the end surface adjacent each groove radially inwardly of the inner surface.

Abstract: A method of manufacturing a valve sleeve including the steps of providing a tubular member having a plurality of grooves extending axially along an inner surface of the tubular member through a pair of axially opposite end surfaces of the tubular member. The end surfaces extend radially outward from an inner surface of the tubular member to an outer surface. Each of the axially extending grooves have a base surface located between the inner and outer surfaces. The method also includes forcefully abutting a first punch against at least one of the end surfaces between the base surface of each groove and the outer surface to displace material of the end surface adjacent each groove radially inwardly of the inner surface. The method also includes then forcefully abutting a second punch against the displaced material of the end surface which extends radially inwardly of the inner surface and moving a portion of the displaced material axially and radially outwardly to form a seal land at an end of each groove.