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How to improve the stability of the bellows compensator?

Edit:Dongguan Dabeini Electronics Co., Ltd.UpDate:2019-12-06

A bellows PTFE expansion joint (compensator) is an expansion joint made of a metal bellows. It can expand and contract in the direction of the axis and also allows a few twists and turns. The bellows expansion joint is a common axial bellows expansion joint, which is used for axial length compensation on the pipeline.

Instability is a precursor to damage. From the critical load formula of the bellows, it can be seen that there are three ways to improve the stability of the bellows: ① increase the thickness of the pipe wall; ② reduce the ratio of the outer diameter to the inner diameter;

In order to avoid exceeding the allowable compensation amount, a maintenance rod or a maintenance ring is provided at both ends of the corrugated pipe, and a guide bracket is provided at the two ends of the pipe connected to it. There are also corner and lateral expansion joints that can be used to compensate for corner and lateral deformation of the pipeline. The advantages of this type of expansion joint are space saving, material saving, easy standardization and mass production, and the disadvantage is shorter life. Bellows expansion joints are generally used for short length pipes with low temperature and pressure. With the improvement of the production technology of bellows, the range of use of such expansion joints is expanding.

The bellows compensator is assembled by the bellows and the compensator, because the bellows compensator must take relevant measures before work, so that the life of the bellows compensator is long.

The structural characteristics of PTFE bellows compensators indicate that their rigidity in the radial direction is much higher than that of the blank, but the axial stiffness is much lower than that of the blank. In a working state with a large load, although its strength is satisfactory and there is ample stiffness in the radial direction, the rigidity in the axial direction does not necessarily satisfy the requirements for use.

However, excessively increasing the thickness of the pipe wall and reducing the ratio of the outer diameter to the inner diameter results in increased rigidity but reduced flexibility, which does not meet the relevant regulations for thin-walled corrugated compensators; excessively reduced the number of useful ripples , Expanding its slenderness ratio, and making it unable to satisfy the requirements for the use of a certain compensation amount.

In this way, we are forced to consider from the external factors, that is, to improve the stability of the bellows used as a compensator by means of inner bushings, outer sheaths, trough reinforcement rings or composite structures. Wherever the compensator adopts the inner bushing or outer sheath structure, because the gap in the radial direction is small, it generally does not need to accept lateral and angular displacement, and is only used for axial compensation of the pipeline. For any corrugated compensator adopting the trough reinforced ring structure, its axial, lateral, and angular displacement compensation must be calculated based on its detailed dimensions.