The meaning and characteristics of sleeve type expansion joint are introduced.
Sleeve type expansion joint has the advantages of small size, easy operation, rapid, no special tools, wide range of application and few product specifications. It does not need to be heated by fire, and after installation, moving or bending will not cause the internal layers of the attachment to be disconnected as in the case of sleeve type expansion joints. Compared with the sleeve type expansion joint, it does not have as many specifications corresponding to the pipe section as the sleeve type expansion joint, although both rely on elastic compression force to secure the internal interface characteristics. The components of the sleeve type expansion joint are not under tension until they are installed on the pipe, while the sleeve type expansion joint is under high tension.
It is guaranteed that there should be no obvious deformation or elastic stress relaxation in the sleeve type expansion joint during the storage period, otherwise it cannot guarantee sufficient elastic compression force after installation on the pipeline, and thus cannot guarantee good interface characteristics. To the site set to the designated position, withdraw the bracket to make it shrink naturally. This technology is the cold shrinkage technology, so this cold shrinkage accessories have good "elasticity", can avoid the pipeline thermal expansion and contraction due to the atmospheric environment, pipeline operation in the load of high and low.
That is, the "pipe breathing" generated by the gap between the insulation, resulting in breakdown accidents. The big disadvantage of the sleeve type expansion joint is that it is not flexible. Can not breathe with the pipe. Therefore, the full cold shrinkage of the attachment for the temperature difference, the use of the climate environment is a good choice. The relative insulation is to prevent the electric charge from high potential to low potential creeping distance. Cold shrink silicone rubber material has good elasticity, as long as the design is reasonable, its strong resilience both enough holding force.
Regardless of the environment occurs hot or cold expansion and contraction, cold shrinkage accessories are tightly hugging the part of the pipe being hugged. This prevents the inhalation of water and moisture, the sleeve type expansion joint distance is well protected, while the full cold shrinkage pipe head of the internal climbing distance in theory as long as 70mm is enough, in more considerations, still design the running distance of 90MM. heat shrinkage pipe head shrinkage temperature of 100 ℃ -140 ℃, only when installed, the temperature can meet its contraction conditions.
When the temperature is low, because the thermal expansion coefficient of the pipe is different from the expansion coefficient of the sleeve type expansion joint, it is possible to produce delamination in the environment below 80℃, so cracks appear. This allows water and moisture to enter by respiration, thus destroying the insulation of the system. However, when the conditions of the environment change, it does not have the same elasticity as silicone rubber, so it can also give impact, which is the disadvantage of sleeve type expansion joint.
