Development history of metal bellows

At first, people sewed animal skins into tubular structures to meet the needs of production struggle. After a long time, by the end of17th century, the Wandell Gegin brothers in the Netherlands had made a canvas hose with longitudinal stitching, which was widely used in the fire fighting industry at that time. Later, with the appearance of rubber in the international market and the development of vulcanization technology, rubber hoses and rubber hoses armored with fabrics such as metal wires or hemp ropes appeared. However, some high-temperature media such as steam, hot air' liquid hydrogen', low-temperature media such as liquid oxygen and liquid helium, and corrosive media such as gasoline, kerosene, acid and alkali can't be transported by rubber hose. Especially at high temperature, its safety and reliability are more difficult to guarantee.

Therefore, people gradually focus on the metal tube, change the geometric shape of the metal tube, and make its inner and outer surfaces produce corresponding ripples. This not only has the flexibility of rubber hose, but also has the characteristics of high temperature resistance, low temperature resistance, aging resistance and corrosion resistance. Therefore, the metal bellows as the main body of the metal hose is produced.

1855, Germany first published the patent for manufacturing bellows. It used the principle of making jewelry at that time to make bellows. Thirty years later, E.Levavasseur of France cooperated with H.Witzenmann of Germany to develop a new type of metal bellows, and obtained the patents of France and Germany in August 1885.

This spiral corrugated pipe is formed by winding a metal belt with S-shaped cross section on special equipment. Put rubber belt, cotton cloth or asbestos rope on the bite of two adjacent turns to facilitate the sealing of the inner cavity of corrugated pipe.

1894, the structure of this corrugated pipe was improved: two metal strips with different diameters were wound in the opposite direction. In this way, the metal belts reach mutual balance under the stress state, and the disadvantages of spontaneous expansion are overcome.

1929, another technical revolution was carried out in the structure of corrugated pipe, which completely solved the problem that the corrugated pipe lost its sealing performance due to the uneven change of the groove of rubber belt or asbestos rope when bending, and opened up a broad prospect for the development of corrugated pipe. People use steel and copper-zinc alloy materials to make an integral bellows, just to use it.

Bellows made of seamless or welded pipes rely on the elastic deformation of corrugated side walls to maintain a certain degree of compressibility or ductility, while ensuring reliable sealing.

Since 1950s, double-layer, three-layer and multi-layer bellows, especially ultra-thin stainless steel bellows, have developed rapidly. In order to meet the use requirements, people use welding, electroforming, machining, hydraulic and mechanical spinning to manufacture corrugated pipes. The minimum nominal diameter is 2 mm, the maximum nominal diameter can reach 400 ~ 500 mm, and there are even giant corrugated pipes with a diameter of 10 m. The number of ripples is at least l ~ 2, and it can reach hundreds, thousands or even tens of thousands at most.

Judging from the significance of bellows as the body of metal hose, the development of metal bellows means the development of metal hose.

Subsequently, people coated the outer surface of corrugated pipe with rubber, plastic or nylon, and armored it with a net sleeve made of metal wire or metal belt, which changed various joint forms. In order to meet the different requirements under various use conditions, various forms of metal hoses have been produced.