補(bu)(bu)(bu)償器(qi)習(xi)慣上也叫膨脹(zhang)節，或(huo)(huo)伸縮(suo)節。由(you)(you)構成其(qi)工(gong)作(zuo)主體的(de)波紋管(guan)(guan)(guan)(guan)（一(yi)種彈(dan)性元件(jian)(jian)）和(he)端管(guan)(guan)(guan)(guan)、支(zhi)架、法蘭、導管(guan)(guan)(guan)(guan)等附件(jian)(jian)組成。 屬于一(yi)種補(bu)(bu)(bu)償元件(jian)(jian)。利用(yong)(yong)其(qi)工(gong)作(zuo)主體波紋管(guan)(guan)(guan)(guan)的(de)有效(xiao)伸縮(suo)變(bian)形(xing)，以吸收管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容(rong)器(qi)等由(you)(you)熱(re)脹(zhang)冷(leng)縮(suo)等原因(yin)而(er)產生的(de)尺寸變(bian)化，或(huo)(huo)補(bu)(bu)(bu)償管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容(rong)器(qi)等的(de)軸向、橫向和(he)角向位移(yi)。也可用(yong)(yong)于降噪減振。在(zai)現(xian)代工(gong)業(ye)中用(yong)(yong)途(tu)廣泛(fan)。供(gong)熱(re)上，為了防止(zhi)供(gong)熱(re)管(guan)(guan)(guan)(guan)道升溫時，由(you)(you)于熱(re)伸長(chang)(chang)或(huo)(huo)溫度應力(li)而(er)引起(qi)管(guan)(guan)(guan)(guan)道變(bian)形(xing)或(huo)(huo)破壞，需要在(zai)管(guan)(guan)(guan)(guan)道上設置補(bu)(bu)(bu)償器(qi)，以補(bu)(bu)(bu)償管(guan)(guan)(guan)(guan)道的(de)熱(re)伸長(chang)(chang)，從而(er)減小管(guan)(guan)(guan)(guan)壁的(de)應力(li)和(he)作(zuo)用(yong)(yong)在(zai)閥件(jian)(jian)或(huo)(huo)支(zhi)架結構上的(de)作(zuo)用(yong)(yong)力(li)。