補(bu)(bu)償器(qi)習慣上(shang)也(ye)叫膨脹(zhang)節，或(huo)(huo)伸(shen)(shen)縮節。由構成其工(gong)作主體(ti)的(de)(de)波紋管(guan)(guan)(guan)（一(yi)種彈性元件(jian)(jian)）和端管(guan)(guan)(guan)、支(zhi)架、法蘭、導(dao)管(guan)(guan)(guan)等附件(jian)(jian)組成。 屬于一(yi)種補(bu)(bu)償元件(jian)(jian)。利用(yong)(yong)其工(gong)作主體(ti)波紋管(guan)(guan)(guan)的(de)(de)有效伸(shen)(shen)縮變(bian)形(xing)，以(yi)吸(xi)收管(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)、容器(qi)等由熱(re)脹(zhang)冷(leng)縮等原因而(er)(er)產生的(de)(de)尺寸(cun)變(bian)化，或(huo)(huo)補(bu)(bu)償管(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)、容器(qi)等的(de)(de)軸向、橫向和角向位移。也(ye)可(ke)用(yong)(yong)于降(jiang)噪(zao)減振。在(zai)現代(dai)工(gong)業中用(yong)(yong)途廣(guang)泛。供熱(re)上(shang)，為了防(fang)止供熱(re)管(guan)(guan)(guan)道(dao)升溫(wen)時，由于熱(re)伸(shen)(shen)長或(huo)(huo)溫(wen)度應力而(er)(er)引起管(guan)(guan)(guan)道(dao)變(bian)形(xing)或(huo)(huo)破壞(huai)，需(xu)要在(zai)管(guan)(guan)(guan)道(dao)上(shang)設置補(bu)(bu)償器(qi)，以(yi)補(bu)(bu)償管(guan)(guan)(guan)道(dao)的(de)(de)熱(re)伸(shen)(shen)長，從而(er)(er)減小(xiao)管(guan)(guan)(guan)壁的(de)(de)應力和作用(yong)(yong)在(zai)閥(fa)件(jian)(jian)或(huo)(huo)支(zhi)架結構上(shang)的(de)(de)作用(yong)(yong)力。