補償(chang)器(qi)習慣上也(ye)叫膨脹(zhang)節，或(huo)伸(shen)(shen)縮節。由(you)(you)構成(cheng)其工(gong)作主體(ti)的波紋(wen)管(guan)(guan)(guan)(guan)（一種彈性元(yuan)件(jian)）和(he)(he)端管(guan)(guan)(guan)(guan)、支(zhi)架(jia)、法蘭、導管(guan)(guan)(guan)(guan)等附件(jian)組成(cheng)。 屬于一種補償(chang)元(yuan)件(jian)。利用(yong)其工(gong)作主體(ti)波紋(wen)管(guan)(guan)(guan)(guan)的有效(xiao)伸(shen)(shen)縮變形(xing)，以吸收(shou)管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器(qi)等由(you)(you)熱脹(zhang)冷縮等原因而(er)產生的尺寸(cun)變化，或(huo)補償(chang)管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器(qi)等的軸(zhou)向、橫向和(he)(he)角向位(wei)移。也(ye)可用(yong)于降噪減振。在(zai)現代工(gong)業中用(yong)途廣泛。供(gong)(gong)熱上，為(wei)了防止供(gong)(gong)熱管(guan)(guan)(guan)(guan)道升溫(wen)(wen)時，由(you)(you)于熱伸(shen)(shen)長或(huo)溫(wen)(wen)度應力而(er)引起管(guan)(guan)(guan)(guan)道變形(xing)或(huo)破壞，需要在(zai)管(guan)(guan)(guan)(guan)道上設置補償(chang)器(qi)，以補償(chang)管(guan)(guan)(guan)(guan)道的熱伸(shen)(shen)長，從而(er)減小管(guan)(guan)(guan)(guan)壁(bi)的應力和(he)(he)作用(yong)在(zai)閥件(jian)或(huo)支(zhi)架(jia)結構上的作用(yong)力。