補償器(qi)(qi)習慣上(shang)(shang)(shang)也(ye)叫膨脹節，或伸縮節。由構成其工作(zuo)主體的(de)波(bo)紋管(guan)(guan)(guan)（一種彈(dan)性元(yuan)件(jian)）和端管(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)等(deng)附件(jian)組(zu)成。 屬于一種補償元(yuan)件(jian)。利用(yong)(yong)其工作(zuo)主體波(bo)紋管(guan)(guan)(guan)的(de)有(you)效伸縮變形，以吸收管(guan)(guan)(guan)線、導管(guan)(guan)(guan)、容(rong)器(qi)(qi)等(deng)由熱(re)脹冷縮等(deng)原因而產(chan)生的(de)尺寸變化(hua)，或補償管(guan)(guan)(guan)線、導管(guan)(guan)(guan)、容(rong)器(qi)(qi)等(deng)的(de)軸向(xiang)、橫向(xiang)和角向(xiang)位移。也(ye)可用(yong)(yong)于降噪減振。在現代工業中(zhong)用(yong)(yong)途廣泛。供(gong)熱(re)上(shang)(shang)(shang)，為了防(fang)止供(gong)熱(re)管(guan)(guan)(guan)道升溫(wen)時，由于熱(re)伸長或溫(wen)度應力而引(yin)起管(guan)(guan)(guan)道變形或破壞，需要在管(guan)(guan)(guan)道上(shang)(shang)(shang)設(she)置補償器(qi)(qi)，以補償管(guan)(guan)(guan)道的(de)熱(re)伸長，從而減小管(guan)(guan)(guan)壁的(de)應力和作(zuo)用(yong)(yong)在閥件(jian)或支架結構上(shang)(shang)(shang)的(de)作(zuo)用(yong)(yong)力。