補(bu)(bu)(bu)償(chang)器(qi)習慣上(shang)也(ye)叫膨脹節，或(huo)(huo)伸(shen)(shen)縮節。由構成(cheng)(cheng)其(qi)工(gong)作主體的(de)波(bo)紋(wen)管(guan)(guan)(guan)(guan)（一種(zhong)彈性元件）和(he)端(duan)管(guan)(guan)(guan)(guan)、支架、法蘭(lan)、導管(guan)(guan)(guan)(guan)等附件組成(cheng)(cheng)。 屬于一種(zhong)補(bu)(bu)(bu)償(chang)元件。利用(yong)其(qi)工(gong)作主體波(bo)紋(wen)管(guan)(guan)(guan)(guan)的(de)有效伸(shen)(shen)縮變(bian)形，以吸收(shou)管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器(qi)等由熱脹冷縮等原因而產生的(de)尺寸變(bian)化，或(huo)(huo)補(bu)(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器(qi)等的(de)軸向、橫(heng)向和(he)角向位移。也(ye)可用(yong)于降噪減振(zhen)。在現代工(gong)業(ye)中用(yong)途(tu)廣(guang)泛。供熱上(shang)，為了防止供熱管(guan)(guan)(guan)(guan)道升(sheng)溫時(shi)，由于熱伸(shen)(shen)長或(huo)(huo)溫度應(ying)力(li)而引起管(guan)(guan)(guan)(guan)道變(bian)形或(huo)(huo)破壞，需(xu)要在管(guan)(guan)(guan)(guan)道上(shang)設(she)置補(bu)(bu)(bu)償(chang)器(qi)，以補(bu)(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)道的(de)熱伸(shen)(shen)長，從而減小管(guan)(guan)(guan)(guan)壁的(de)應(ying)力(li)和(he)作用(yong)在閥件或(huo)(huo)支架結構上(shang)的(de)作用(yong)力(li)。