補償器(qi)習慣上也(ye)叫(jiao)膨脹節，或(huo)伸縮節。由(you)構成其工作主體的(de)(de)波紋管(guan)(guan)(guan)(guan)（一種彈性元件(jian)(jian)）和(he)端(duan)管(guan)(guan)(guan)(guan)、支架、法蘭、導(dao)(dao)(dao)管(guan)(guan)(guan)(guan)等(deng)附(fu)件(jian)(jian)組成。 屬于一種補償元件(jian)(jian)。利用(yong)(yong)其工作主體波紋管(guan)(guan)(guan)(guan)的(de)(de)有效伸縮變(bian)形，以(yi)(yi)吸收管(guan)(guan)(guan)(guan)線、導(dao)(dao)(dao)管(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)由(you)熱脹冷縮等(deng)原因而產(chan)生的(de)(de)尺(chi)寸變(bian)化，或(huo)補償管(guan)(guan)(guan)(guan)線、導(dao)(dao)(dao)管(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)的(de)(de)軸向、橫向和(he)角向位移。也(ye)可用(yong)(yong)于降噪減振(zhen)。在現代(dai)工業中用(yong)(yong)途廣泛。供(gong)熱上，為(wei)了防止(zhi)供(gong)熱管(guan)(guan)(guan)(guan)道升溫時，由(you)于熱伸長或(huo)溫度(du)應力而引起(qi)管(guan)(guan)(guan)(guan)道變(bian)形或(huo)破壞，需要在管(guan)(guan)(guan)(guan)道上設(she)置補償器(qi)，以(yi)(yi)補償管(guan)(guan)(guan)(guan)道的(de)(de)熱伸長，從(cong)而減小管(guan)(guan)(guan)(guan)壁的(de)(de)應力和(he)作用(yong)(yong)在閥(fa)件(jian)(jian)或(huo)支架結構上的(de)(de)作用(yong)(yong)力。