補(bu)(bu)償(chang)器(qi)習慣上也叫膨脹(zhang)節，或(huo)伸縮(suo)節。由構(gou)成其工(gong)作主體的(de)波紋管(guan)(guan)(guan)(guan)(guan)(guan)（一種(zhong)彈性(xing)元件(jian)）和(he)端管(guan)(guan)(guan)(guan)(guan)(guan)、支架、法蘭、導(dao)管(guan)(guan)(guan)(guan)(guan)(guan)等(deng)附件(jian)組成。 屬(shu)于一種(zhong)補(bu)(bu)償(chang)元件(jian)。利用其工(gong)作主體波紋管(guan)(guan)(guan)(guan)(guan)(guan)的(de)有效伸縮(suo)變形，以吸收管(guan)(guan)(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)由熱(re)脹(zhang)冷(leng)縮(suo)等(deng)原因而(er)產生的(de)尺寸(cun)變化，或(huo)補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)的(de)軸向、橫向和(he)角向位移。也可(ke)用于降噪(zao)減(jian)振。在(zai)現代工(gong)業中用途廣泛。供熱(re)上，為了防止供熱(re)管(guan)(guan)(guan)(guan)(guan)(guan)道升溫時，由于熱(re)伸長或(huo)溫度應力而(er)引起管(guan)(guan)(guan)(guan)(guan)(guan)道變形或(huo)破壞，需要(yao)在(zai)管(guan)(guan)(guan)(guan)(guan)(guan)道上設置補(bu)(bu)償(chang)器(qi)，以補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)道的(de)熱(re)伸長，從而(er)減(jian)小管(guan)(guan)(guan)(guan)(guan)(guan)壁的(de)應力和(he)作用在(zai)閥件(jian)或(huo)支架結構(gou)上的(de)作用力。