Bellows used for polytetrafluoroethylene compensator and manufacturing method thereof

Abstract

The invention relates to a bellows manufacturing technique, particularly relates to a bellows applied to a polytetrafluor ethylene compensator and a manufacturing method thereof. An inner polytetrafluor ethylene corrugated layer, a metal corrugated layer and an outer polytetrafluor ethylene corrugated layer are successively melted into an integrated body; the two diagonals of the unit grid in the metal corrugated layer are identical with the axial direction and radial direction of the bellows respectively; during the manufacturing process, the two diagonals of the quadrangular unit grid in the metal grid are laid around the polytetrafluor ethylene film in the directions identical with the axial direction and radial direction of the cylindrical mould. The technique is aimed at providing a bellows with strong capability to bear positive and negative pressures for a polytetrafluor ethylene compensator and as well as the manufacturing method. Compared with the prior art, the bellows has certain rigidity, the service life is long, small-bore bellows capable of bearing positive and negative pressures can be manufactured more easily, and the capability of the polytetrafluor ethylene compensator is improved, and so on.

Description

technical field [0001] The invention relates to a bellows manufacturing technology, in particular to a bellows used for a polytetrafluoroethylene compensator and a manufacturing method thereof. Background technique [0002] The compensator is an indispensable pipe fitting for compensating the displacement of the pipeline caused by thermal expansion and contraction in petroleum, chemical, smelting and acid making industries, among which the bellows is the core component of the compensator. [0003] At present, in industries with serious corrosion such as petroleum, chemical industry, smelting and acid making, the commonly used compensators lined with PTFE include metal bellows compensators (patent number: 96240233.8), PTFE metal tube reinforced Compensator (Patent No.: 92104090.3), etc., in these disclosed patented technologies, their bellows are made of polytetrafluoroethylene material, in order to improve the strength of the bellows, a reinforcing layer is provided outside ...

AI Technical Summary

Problems solved by technology

Its disadvantages: 1. The opening end of the opening reinforcement ring with the outer polytetrafluoroethylene anti-corrosion layer is squeezed by force during use, and the polytetrafluoroethylene anti-corrosion layer is easy to be worn, so that the metal in the opening reinforcement ring is exposed , causing the corrosive medium to continuously corrode and damage the split reinforcement ring, so that all the split reinforcement rings gradually lose their supporting function, and the bellows lose the ability to withstand negative pressure until the entire compensator is scrapped

2. For small-diameter corrugated pipes (DM<50mm), it is not possible to set an opening reinforcement ring with a polytetrafluoroethylene anti-corrosion layer in the inner depression of the bellows

3. It only acts as a negative pressure-resistant function in the depression inside the bellows, and other parts around the bellows do not have the ability to withstand negative pressure

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