Installation of corrugated expansion joints and precautions

Installation of corrugated expansion joints and precautions
Only one expansion joint (or a group of angular expansion joints) can be installed between two fixed pipe frames. Corrugated expansion joints are much easier to install than rigid pipes, and some deviations of the pipes can be compensated by the expansion joints. However, this does not mean that there can be no requirements for the installation of the pipe. Because if the installation has absorbed a large displacement, when working, its service life should be affected. Therefore, in principle, the use of expansion joints to compensate for installation deviations is not advocated. As a rule, the above-mentioned basic forms of expansion joints do not absorb torsional moments and therefore do not allow expansion joints to be subjected to torsion when they are installed. The fixing bracket must be strong enough to ensure that the expansion joint is not damaged. The guiding bracket must be sufficiently guided, otherwise, it affects the transmission of pipeline displacement. Pre-stretching or cold tightening of expansion joints. In order to ensure that the corrugated expansion joint compensates within the interval set by the structure and to reduce its deformation stiffness force, the expansion joint in the supplied state should be pre-deformed according to the installation temperature on site.
 
Installation precautions
 
1 . Pipeline alignment should be good, in other methods are not guaranteed, can be used after the laying of straight pipe cut a section in the installation of expansion joints to ensure the method.
2 . The bellows should be protected during installation, so as not to bruise the bellows.
3 . With the expansion joint of the guide sleeve, should make the direction of the guide flow with the media flow direction.
4 . After installation, the pre-stretching rod and the transportation fixing rod should be removed so that the expansion and contraction of the pipe can be compensated when the ambient temperature changes.
5 . The bracket must meet the design requirements, it is strictly forbidden to test pressure in the pipeline before the bracket is installed, so as not to pull the expansion joint bad.
6 . Insulation layer should be done on the expansion joint outer protection sleeve, shall not sit directly on the bellows. Shall not use the insulation material containing chlorine.
7 . Expansion joints are allowed not more than 1.5 times the nominal pressure of the system pressure test.
8 . Fitted with expansion joints in the operation of the pipeline, valve opening and closing, to be carried out gradually, so as to avoid rapid changes in temperature and pressure in the pipeline, resulting in damage to the bracket or expansion joint.