Weldless joint metal hose and producing method thereof

Abstract

The invention relates to a weldless connection metallic hose and its manufacture method, in which a neck connecting tube is disposed between the hose body and its joint and light pipes at two ends of the stainless steel corrugated tube are inserted into the internal hole of the neck connecting tube. A flanging at the end is clamped between the joint and the end face of the connecting tube mounted a seal washer, and they are integrated via a fastener. The hose-manufacturing method is charactized by making a double-layer flanging at the end port of the corrugated tube by the process of forming, flatting, cutting and turning up and integrating the joint, the flanging and the neck connecting tube via a fastener. The invention uses a cold-forming process method instead of traditional bonding technology, so it has improved the stress state of the member material.

Description

technical field [0001] The invention relates to a metal hose mainly used in a fluid conveying pipeline and a stainless steel corrugated pipe, and also relates to a manufacturing method of the metal hose. Background technique [0002] Metal hoses are widely used in many industries such as military industry, petroleum, chemical industry, electric power, metallurgy, printing and dyeing, papermaking, domestic heating, construction, etc. It is suitable for pipeline systems that transport fluid media where one end is fixed and the other end needs to be moved, or both ends need to be moved. , must be able to withstand high pressure, corrosion resistance, vibration resistance. Metal hoses are generally composed of stainless steel bellows, stainless steel mesh sleeves and joints, and the joints include threaded joints and flange joints, which are divided into fixed and movable types. The existing metal flexible pipe is that the end faces of the bellows and the net sleeve are directl...

AI Technical Summary

Problems solved by technology

The metal hose of this welded joint is not well stressed. Due to the sudden change in the shape of the welded components, the thickness difference between the bellows pipe wall and the joint is large, causing stress concentration, and the thermal expansion and contraction of the welding area, resulting in additional thermal stress. , so the stress condition of the weld is deteriorated, and the hose is working under dynamic conditions and subjected to alternating stress, so the weld is more prone to fatigue damage

The corrosion resistance of this welded metal hose is also not good. Due to the extremely high temperature generated during welding, the corrosion-resistant elements such as Cr and Ni in the stainless steel are partially burned, and a chromium-poor and nickel-poor area is formed in the heat-affected zone of the weld. It is easy to be damaged by corrosion; and the weld is rough and uneven, especially the weld on the inner wall of the hose is very rough. If the corrosive medium is transported, the corrosion degree of the weld will be further aggravated, and it is inevitable to produce pinch during welding. Defects such as slag, pores, cracks, etc. affect product quality, so the existing welded metal hose has short service life, unreliable quality and high operating cost

In addition, the welding method has the obvious disadvantage of low production efficiency for mass production.

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