Compound expansion joint used in petrochemical field

Abstract

The invention provides a compound expansion joint used in the petrochemical field. The compound expansion joint used in the petrochemical field is provided with an intermediate pipe assembly. Heat insulation linings are arranged on the inner wall of the intermediate pipe assembly, and two ends of the intermediate pipe assembly are separately connected to a set of external pressing corrugated pipeassemblies arranged back to back. The external pressing corrugated pipe assemblies comprise end pipes, corrugated pipes, corrugated pipe connection pipes, end ring assemblies, outer pipes, retaining ring assemblies with thermal insulation ceramic fibers, flow-guiding barrel assemblies with wear-resistant linings and dust-proof sealing rings, the corrugated pipes sleeves the end pipes, the heat insulation linings are arranged on the inner walls of the end pipes, one ends of the corrugated pipes are fixedly connected with the ends, close to the direction of an expansion center, of the end pipesthrough the corrugated pipe connection pipes, the other ends of the corrugated pipes are connected with one ends of the outer pipes through end ring assemblies sleeving the end pipes and having gaps with the end pipes, and the other ends of the outer pipes are connected to the intermediate pipe assembly. The compound expansion joint can completely solve the problem of corrosion failure of a cold wall pipeline high temperature expansion joint of a large refining and chemical plant, and the cost of expansion joint is reduced.

Description

technical field [0001] The invention relates to the technical field of expansion joints, in particular to a compound expansion joint used in the petrochemical field. Background technique [0002] The bellows expansion joint is a thermal compensation component widely used in connecting pipelines between catalytic cracking (FCC / DCC) units in refineries to reduce the temperature stress of the pipeline and ensure the safety of the pipeline. The maximum temperature of the regenerator and energy recovery system is 600~750 ℃, and its medium (flue gas) contains a variety of corrosive components. The expansion joints used for compensating cold wall pipelines in these devices have the most serious corrosion problems, most of which are polythionic acid corrosion Cracking; the timing of corrosion of expansion joint bellows is the shutdown and maintenance stage of the normally open pipeline and the shutdown stage of the spare pipeline that is not normally open, and it will not occur duri...

AI Technical Summary

Problems solved by technology

After the bellows material is upgraded, the corrosion resistance of the expansion joint has been improved to a certain extent, and the probability of corrosion failure of the expansion joint has been reduced. The material is precious metal, resulting in an increase in the price of the expansion joint and an increase in the construction cost of the device

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