補償器(qi)習(xi)慣上(shang)也叫膨脹(zhang)節(jie)，或(huo)伸(shen)(shen)縮節(jie)。由構成其工作主體(ti)的(de)(de)(de)波紋(wen)(wen)管(guan)(guan)(guan)(guan)(guan)（一(yi)種彈性元(yuan)件(jian)(jian)）和端管(guan)(guan)(guan)(guan)(guan)、支架、法(fa)蘭、導管(guan)(guan)(guan)(guan)(guan)等附件(jian)(jian)組成。 屬于(yu)一(yi)種補償元(yuan)件(jian)(jian)。利用(yong)(yong)其工作主體(ti)波紋(wen)(wen)管(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)有效伸(shen)(shen)縮變(bian)形，以(yi)吸收管(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)、容器(qi)等由熱(re)(re)脹(zhang)冷縮等原(yuan)因而產生的(de)(de)(de)尺寸(cun)變(bian)化，或(huo)補償管(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)、容器(qi)等的(de)(de)(de)軸向(xiang)、橫向(xiang)和角向(xiang)位移。也可用(yong)(yong)于(yu)降(jiang)噪(zao)減(jian)振(zhen)。在現代工業中用(yong)(yong)途廣泛。供(gong)熱(re)(re)上(shang)，為了防止(zhi)供(gong)熱(re)(re)管(guan)(guan)(guan)(guan)(guan)道升溫時，由于(yu)熱(re)(re)伸(shen)(shen)長(chang)(chang)或(huo)溫度應(ying)力而引起管(guan)(guan)(guan)(guan)(guan)道變(bian)形或(huo)破壞，需(xu)要在管(guan)(guan)(guan)(guan)(guan)道上(shang)設置補償器(qi)，以(yi)補償管(guan)(guan)(guan)(guan)(guan)道的(de)(de)(de)熱(re)(re)伸(shen)(shen)長(chang)(chang)，從(cong)而減(jian)小管(guan)(guan)(guan)(guan)(guan)壁的(de)(de)(de)應(ying)力和作用(yong)(yong)在閥件(jian)(jian)或(huo)支架結構上(shang)的(de)(de)(de)作用(yong)(yong)力。