補(bu)償器(qi)習慣上(shang)也(ye)叫(jiao)膨脹(zhang)節，或(huo)伸(shen)縮(suo)節。由構成其(qi)工作(zuo)主體的波紋管(guan)(guan)(guan)(guan)（一(yi)種彈性元件(jian)(jian)(jian)）和端管(guan)(guan)(guan)(guan)、支(zhi)架(jia)、法蘭、導(dao)(dao)管(guan)(guan)(guan)(guan)等(deng)附件(jian)(jian)(jian)組成。 屬于一(yi)種補(bu)償元件(jian)(jian)(jian)。利用(yong)其(qi)工作(zuo)主體波紋管(guan)(guan)(guan)(guan)的有效伸(shen)縮(suo)變形，以吸收管(guan)(guan)(guan)(guan)線、導(dao)(dao)管(guan)(guan)(guan)(guan)、容器(qi)等(deng)由熱脹(zhang)冷縮(suo)等(deng)原(yuan)因而產生(sheng)的尺(chi)寸變化(hua)，或(huo)補(bu)償管(guan)(guan)(guan)(guan)線、導(dao)(dao)管(guan)(guan)(guan)(guan)、容器(qi)等(deng)的軸向、橫向和角向位移。也(ye)可用(yong)于降噪減(jian)(jian)振。在(zai)(zai)現(xian)代工業(ye)中用(yong)途廣泛。供熱上(shang)，為了防止供熱管(guan)(guan)(guan)(guan)道升溫時，由于熱伸(shen)長或(huo)溫度(du)應力而引起管(guan)(guan)(guan)(guan)道變形或(huo)破壞，需(xu)要在(zai)(zai)管(guan)(guan)(guan)(guan)道上(shang)設置補(bu)償器(qi)，以補(bu)償管(guan)(guan)(guan)(guan)道的熱伸(shen)長，從而減(jian)(jian)小(xiao)管(guan)(guan)(guan)(guan)壁的應力和作(zuo)用(yong)在(zai)(zai)閥件(jian)(jian)(jian)或(huo)支(zhi)架(jia)結構上(shang)的作(zuo)用(yong)力。