補償器習慣上也叫(jiao)膨脹節，或(huo)(huo)伸(shen)(shen)縮(suo)(suo)節。由(you)(you)構成(cheng)其(qi)工(gong)作主體的(de)波紋(wen)管(guan)(guan)(guan)（一種彈性元(yuan)件(jian)）和端(duan)管(guan)(guan)(guan)、支架(jia)、法蘭、導管(guan)(guan)(guan)等(deng)附(fu)件(jian)組(zu)成(cheng)。 屬于一種補償元(yuan)件(jian)。利(li)用(yong)(yong)(yong)其(qi)工(gong)作主體波紋(wen)管(guan)(guan)(guan)的(de)有效伸(shen)(shen)縮(suo)(suo)變形，以吸收管(guan)(guan)(guan)線、導管(guan)(guan)(guan)、容(rong)器等(deng)由(you)(you)熱(re)脹冷縮(suo)(suo)等(deng)原(yuan)因而產生的(de)尺寸變化，或(huo)(huo)補償管(guan)(guan)(guan)線、導管(guan)(guan)(guan)、容(rong)器等(deng)的(de)軸向、橫向和角向位移(yi)。也可用(yong)(yong)(yong)于降噪(zao)減振。在現代(dai)工(gong)業中用(yong)(yong)(yong)途廣(guang)泛(fan)。供(gong)熱(re)上，為了防(fang)止供(gong)熱(re)管(guan)(guan)(guan)道(dao)(dao)升溫時(shi)，由(you)(you)于熱(re)伸(shen)(shen)長或(huo)(huo)溫度應力(li)而引(yin)起管(guan)(guan)(guan)道(dao)(dao)變形或(huo)(huo)破壞，需要在管(guan)(guan)(guan)道(dao)(dao)上設(she)置補償器，以補償管(guan)(guan)(guan)道(dao)(dao)的(de)熱(re)伸(shen)(shen)長，從而減小管(guan)(guan)(guan)壁的(de)應力(li)和作用(yong)(yong)(yong)在閥件(jian)或(huo)(huo)支架(jia)結(jie)構上的(de)作用(yong)(yong)(yong)力(li)。