High-pressure metal pipe having connecting head and method of forming the connecting head as well as sleeve washer for the connecting head

摘要

There is provided a high-pressure metal pipe which has a connecting head capable of solving the risk of cavitation erosion in the inside of the connecting head by changing the contour shape of a pocket or notch to be formed in the inside of the connecting head during head working into a contour shape having a shallow depth and a gentle cross section. A reduced-diameter connecting head having an outside circumferential surface which is a seat surface having a truncated conical or spherical shape corresponding to a mating seat is provided at a connecting end portion of a thick-walled steel pipe having a comparatively small diameter. An annular concave groove to be formed in the inside of the connecting head during the formation thereof has a contour shape having a shallow depth and a gentle cross section, and the high-pressure metal pipe has a sleeve washer having a cylindrical portion which covers the outer circumferential surface of the reduced-diameter connecting head.