There are many factors affecting the life of the compensator. One is the failure of the spherical compensator, the other is the corrosion. The compensator used in urban heat network has a theoretical calculation life of about 6000-10000 times, and its safety factor is 15 times. The actual allowable life of the compensator should be greater than 400 times. If a continuous heat network starts about 20 times a year, its allowable normal life should be more than 20 years. This is not the case in practical application. It takes less than three or five years to replace the compensator. There was hardly any compensator installed more than ten years ago. There is a famous saying in the design that "corrosion begins with drawings". It requires us not only to fix the position of the bracket reasonably, but also to distance the guide bracket appropriately, to prevent the instability of the compensator, but also to consider the design and layout of the guide bracket. Corrosion prevention is often neglected. Through actual inspection, it is found that the compensators arranged in inspection wells or trenches corrode faster, especially the compensators on the water supply pipes in hot water pipeline network inspection wells are the most serious, and the return pipes are basically non-corrosive. The main reason is that the original battery effect is formed in the supply and return water compensators and pipe sections, and electrochemical corrosion occurs. This kind of problem can be solved by the method of design optimization. When arranging compensators, it is better not to arrange side by side. When conditions permit, the spacing of compensators should be enlarged. When laying, it is better to adopt full-buried method without inspection wells and mark well. If it is necessary to locate in inspection wells, it is necessary to do well in waterproof and heat preservation, prevent sewage and rainwater from entering, reduce corrosion conditions and block formation. Galvanic battery effect loop.

Hydraulic test schemes are pre-considered in the design.

An axial compensator is used in a thermal pipeline. During the construction, the construction team adopts piecewise compression test. Temporary blind plates are set at the selected piecewise points by themselves. The force of blind plates does not act on the main fixing bracket, but on the secondary fixing bracket. The fixing bracket was pulled out when the pressure was increased by 1.5 times of the test pressure. When the pipeline of axial compensator is subjected to piecewise compression, the main fixing bracket that can withstand the pressure of hydraulic test should be selected at the piecewise point. If this is not possible, the secondary fixing bracket that can withstand the blind plate force at the piecewise point should be temporarily strengthened so that it can withstand the blind plate force. Because the thrust difference between primary and secondary fixing brackets is too big, it is difficult to implement the temporary reinforcement method, so the best way is to consider the hydraulic test or purge scheme in advance in the design. The location of the sublevel points is best determined jointly by the owner, the designer and the construction unit. The design unit is responsible for the technical disclosure, and the owner organizes the implementation according to the opinions of the design unit.

The influence of construction and installation on the axial compensator:

Sometimes the layout of compensators is unreasonable or the design measures are inappropriate. It is easy to deviate in construction and installation. The direction of force is not the axial force, but the bias force. The bias force produces certain torque to the compensator. For the axial compensator, the pipe wall is thin and the anti-torque ability is poor, and it is very easy to lose stability. Therefore, in order to ensure that the coaxiality tolerance of piping system at the installation of compensators is minimal in construction, it is suggested that the piping section be laid before the installation of compensators, and then cut off a section of pipes at the preparatory installation of compensators, then install the compensators and weld them, and adopt the method of pipe cutting installation. Although a small amount of pipeline waste is caused, the concentricity of pipeline can be guaranteed.