Compensator (expansion joint) is flexible, can be stretched, compressed and bent, and has a certain pressure bearing capacity. In addition to the role of displacement compensation, it also has the functions of shock absorption and noise reduction and sealing. GF is used in industrial fields such as petroleum, chemical industry, electricity, water conservancy, metallurgy and atomic energy. The design of the
compensator (expansion joint) includes the various stress calculations of corrugated pipe and the stress analysis of the fulcrum of the pipe system. The former has standards and regulations at home and abroad; however, the latter has few public documents and cumbersome calculations, which are often overlooked by designers. In industrial equipment, due to improper selection of pipe system fulcrum points, cases of expansion joints and pipe system failure are not uncommon. In addition, material selection and corrosion are also important factors affecting the life of compensator. Some compensator accidents in recent years are mostly related to material selection and corrosion.
At first, compensators (expansion joints) were used more frequently in thermal power plant pipeline systems. Due to the backward manufacturing technology and lack of compensator design principles, it is less used in high-temperature pressure-bearing pipe systems. In the late 1950s, the petrochemical and thermoelectric industries developed rapidly, and the demand for compensators increased. Some industrially developed countries carried out in-depth research on compensator theory and formulated their own compensator design standards for each country. At the same time, the forming and manufacturing technology of compensator (expansion joint) corrugated pipes has also been greatly improved, and different types of series products have been formed.
compensator is no longer a flexible pipe soft joint, but a component that can absorb axial, transverse, and bending thermal displacements at the same time. Especially in the 1960s, due to the shortage of energy in the world, the catalytic cracking of heavy oil developed rapidly, and the technology of flue gas turbine power generation and recycling high-temperature flue gas was successfully developed and industrialized, and the compensator played a key role.
As the scope of use of compensator continues to expand, people accumulate a lot of practical experience. The research work starts to conduct comprehensive tests and evaluations of the strength, instability, fatigue, materials, etc. of compensator from a single stress assessment indicator. In the 1970s, the computer finite element analysis was introduced to calculate the various stresses of the compensator, and compared the calculation results with the experimental results, which greatly promoted the progress of research work. The application scope and function of
compensator
compensator is also commonly called expansion joints or telescopic joints. It consists of corrugated pipe (an elastic element) that constitutes its working body and accessories such as end tubes, brackets, flanges, and conduits. It belongs to a compensation element. The effective expansion and contraction of the corrugated pipe of its working body is used to absorb the dimensional changes caused by thermal expansion and contraction of pipelines, conduits, containers, etc., or to compensate for the axial, lateral and angular displacements of pipelines, conduits, containers, etc. It can also be used for noise reduction and vibration reduction. It is widely used in modern industry. In terms of heating, in order to prevent the pipe from deforming or destroying due to thermal elongation or temperature stress when the heating pipe is heated, a compensator needs to be installed on the pipe to compensate for the thermal elongation of the pipe, thereby reducing the stress on the pipe wall and the force acting on the valve member or bracket structure.
1. The import and export of various pumps, valves, and air compressors;
2. Various fire piping, air conditioning piping, steam piping, etc.;
3. Generally, factory piping and flexible connections are needed; compensators are also required;
4. Compensators are also used in domestic water piping and sanitary occasions;
5. In situations where mechanical equipment piping requires shock absorption and compensation for thermal displacement;
6. In steam turbine generator sets, thermal pipelines, machine pumps and other parts. For example: connecting pipes, steam extraction pipes, exhaust pipes, and condensate pump inlet and outlet pipes between medium and low cylinders, generally using unrestricted compensators, transverse expansion joints, screw expansion joints with chutes, pressure balance expansion joints, etc.
7. The hot water pipe network and steam pipe network used in the thermal power plant area generally adopts expansion joints such as axial, horizontal, and hinged;
8. Applied in high and medium-sized low-temperature hot air ducts, smoke ducts, and high-frequency vibration pipelines and desulfurization pipelines, generally adopts axial, horizontal, hinged, coal powder three-way type, rectangular, high-temperature corrosion-resistant non-metal and ordinary non-metal corrugated compensator .
