Coaxial two-way external pressure type anti-twisting expansion joint

Abstract

The invention discloses a coaxial two-way external pressure type anti-twisting expansion joint. The coaxial two-way external pressure type anti-twisting expansion joint is composed of inner tubes, outer joints, corrugated tubes, inner joints, a key, an outer tube and pins jointly. The inner wall of the middle section of the outer tube is fixedly connected with the key which is arranged in the axial direction. The inner tubes extend into an inner cavity of the outer tube from the two ends of the outer tube respectively. The inner joints, the corrugated tubes and the outer joints are arranged on the overlapping sections between the inner tubes and the outer tube in a sleeved mode to form axial compensation assemblies which are independent of one another, wherein the inner joints, the corrugated tubes and the outer joints are sequentially connected in a sealed mode. The outer wall of each inner joint is provided with an axial open slot matched with the key. The inner joints and the key move relatively to form an axial compensation assembly displacement track structure. Orifices in the two ends of the outer tube are in sealing connection with the matched outer joints respectively to form two symmetrically-arranged axial compensation assembly integrated structures. The coaxial two-way external pressure type anti-twisting expansion joint is simple in structure, high in integration level and capable of conducting independent one-way compensation and synchronous two-way compensation. Built-in coaxial displacement tracks are coaxial, do not influence axial compensation and have an anti-twisting function, so it can be guaranteed that the corrugated tubes only conduct axial displacement movement and the service life of the expansion joint can be prolonged.

Description

Technical field [0001] The present invention relates to a pipeline safety device, in particular, the present invention relates to an expansion joint for heating pipelines, in particular to a coaxial two-way external pressure type anti-torsion expansion joint. Background technique [0002] Due to thermal expansion and contraction of the urban heating pipe network and industrial pipe network, destructive internal stress and corresponding displacement are generated during the operation of the pipe network. For the safety of the pipe network, it is necessary to configure expansion joints at relevant nodes to absorb or Compensate axial thrust and displacement. Internal pressure type axial expansion joints are commonly used in engineering. This type of expansion joint has simple structure, strong compensation capability and low cost, and can achieve the expected compensation purpose. However, the prior art product is an expansion joint with a unidirectional compensation structure, whi...

AI Technical Summary

Problems solved by technology

The degree of freedom of rotation of the prior art products is not limited, and the pipes bearing the axial force in different directions have a tendency to torsion, and frequent torsion is likely to cause fatigue damage to the bellows

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