補(bu)(bu)(bu)償(chang)器習慣上也叫膨脹節，或(huo)伸縮(suo)(suo)節。由構(gou)成(cheng)其(qi)工(gong)作主(zhu)體的(de)(de)波紋管(guan)(guan)(guan)(guan)（一種(zhong)彈性元件(jian)(jian)）和(he)(he)端管(guan)(guan)(guan)(guan)、支(zhi)架(jia)、法(fa)蘭、導管(guan)(guan)(guan)(guan)等附件(jian)(jian)組成(cheng)。 屬于一種(zhong)補(bu)(bu)(bu)償(chang)元件(jian)(jian)。利用(yong)(yong)(yong)其(qi)工(gong)作主(zhu)體波紋管(guan)(guan)(guan)(guan)的(de)(de)有效伸縮(suo)(suo)變形(xing)，以吸收管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容(rong)器等由熱(re)脹冷縮(suo)(suo)等原因而產生的(de)(de)尺寸變化(hua)，或(huo)補(bu)(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容(rong)器等的(de)(de)軸向(xiang)、橫(heng)向(xiang)和(he)(he)角向(xiang)位移。也可用(yong)(yong)(yong)于降(jiang)噪(zao)減(jian)振(zhen)。在(zai)(zai)現代工(gong)業中用(yong)(yong)(yong)途(tu)廣泛(fan)。供(gong)熱(re)上，為了防止供(gong)熱(re)管(guan)(guan)(guan)(guan)道(dao)升溫(wen)時，由于熱(re)伸長(chang)或(huo)溫(wen)度(du)應力而引起管(guan)(guan)(guan)(guan)道(dao)變形(xing)或(huo)破壞，需要在(zai)(zai)管(guan)(guan)(guan)(guan)道(dao)上設置補(bu)(bu)(bu)償(chang)器，以補(bu)(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱(re)伸長(chang)，從(cong)而減(jian)小(xiao)管(guan)(guan)(guan)(guan)壁(bi)的(de)(de)應力和(he)(he)作用(yong)(yong)(yong)在(zai)(zai)閥件(jian)(jian)或(huo)支(zhi)架(jia)結構(gou)上的(de)(de)作用(yong)(yong)(yong)力。