Patent ID: 8814223

Claim:
A flexible pipe connected with a flexible pipe connecting structure, wherein the flexible pipe connecting structure includes a ledge on an outer surface or an inner surface, and wherein the flexible pipe includes a first end portion having ridges and valleys, wherein the flexible pipe is inserted into at least a part of the connecting structure so that the first end portion is held by the ledge, wherein the first end portion is welded to the connecting structure by a filler metal, wherein the connecting structure includes: a body part configured to extend the flexible pipe or connect with another pipe or device; and a connecting part configured to have a smaller thickness than a thickness of the body part, wherein the first end portion is inserted into and welded to the connecting part, wherein the ledge is a step part provided between the body part and the connecting part, wherein the flexible pipe includes spiral ridges and valleys, wherein the connecting part includes spiral ridges and valleys that correspond to the ridges and valleys of the flexible pipe so that the flexible pipe is rotatingly connected to the connecting part, and wherein at least some of the ridges and valleys of the first end portion of the flexible pipe is welded to the valleys and the ridges of the connecting part by the filler metal.