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The corrugated pipe is a flexible element, by the temperature role in the work process, the corrugated tube curvature of each part of the constantly changing, although the curvature changes caused by the deformation is not large, but dirt and metal bellows expansion coefficients vary greatly, so the dirt and corrugated tube surface will produce a large pulling force, enough to make the dirt off the automatic cleaning, automatic cleaning, especially it is a tube and other heat exchangers can be compared.