補償器(qi)習慣上(shang)也叫膨脹(zhang)節，或伸(shen)(shen)縮節。由(you)構(gou)成其(qi)(qi)工作主(zhu)體的(de)波紋(wen)(wen)管(guan)(guan)(guan)(guan)（一種(zhong)彈性元件(jian)(jian)）和端管(guan)(guan)(guan)(guan)、支(zhi)架、法蘭(lan)、導(dao)管(guan)(guan)(guan)(guan)等附件(jian)(jian)組(zu)成。 屬于(yu)一種(zhong)補償元件(jian)(jian)。利(li)用(yong)其(qi)(qi)工作主(zhu)體波紋(wen)(wen)管(guan)(guan)(guan)(guan)的(de)有(you)效伸(shen)(shen)縮變形(xing)，以(yi)吸收管(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)、容(rong)器(qi)等由(you)熱脹(zhang)冷縮等原因而產生的(de)尺寸變化，或補償管(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)、容(rong)器(qi)等的(de)軸(zhou)向(xiang)、橫向(xiang)和角向(xiang)位移。也可用(yong)于(yu)降噪(zao)減振(zhen)。在(zai)現代工業中用(yong)途廣泛(fan)。供(gong)(gong)熱上(shang)，為了防止供(gong)(gong)熱管(guan)(guan)(guan)(guan)道升(sheng)溫時，由(you)于(yu)熱伸(shen)(shen)長或溫度應力而引起管(guan)(guan)(guan)(guan)道變形(xing)或破壞，需要在(zai)管(guan)(guan)(guan)(guan)道上(shang)設(she)置補償器(qi)，以(yi)補償管(guan)(guan)(guan)(guan)道的(de)熱伸(shen)(shen)長，從而減小管(guan)(guan)(guan)(guan)壁的(de)應力和作用(yong)在(zai)閥(fa)件(jian)(jian)或支(zhi)架結構(gou)上(shang)的(de)作用(yong)力。