補(bu)償器(qi)習(xi)慣(guan)上也(ye)叫膨脹(zhang)節，或伸縮節。由(you)構成(cheng)其工作主(zhu)體(ti)的(de)(de)波紋(wen)管(guan)(guan)(guan)(guan)（一(yi)種(zhong)彈性元(yuan)件(jian)）和端管(guan)(guan)(guan)(guan)、支架、法(fa)蘭、導(dao)管(guan)(guan)(guan)(guan)等附件(jian)組成(cheng)。 屬于(yu)一(yi)種(zhong)補(bu)償元(yuan)件(jian)。利用(yong)(yong)其工作主(zhu)體(ti)波紋(wen)管(guan)(guan)(guan)(guan)的(de)(de)有效伸縮變(bian)形(xing)，以吸收管(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)、容器(qi)等由(you)熱(re)脹(zhang)冷縮等原因而產生(sheng)的(de)(de)尺寸變(bian)化，或補(bu)償管(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)、容器(qi)等的(de)(de)軸(zhou)向(xiang)、橫(heng)向(xiang)和角(jiao)向(xiang)位移。也(ye)可用(yong)(yong)于(yu)降噪減振。在(zai)現代工業中(zhong)用(yong)(yong)途廣(guang)泛(fan)。供熱(re)上，為了防止供熱(re)管(guan)(guan)(guan)(guan)道(dao)升(sheng)溫(wen)(wen)時，由(you)于(yu)熱(re)伸長或溫(wen)(wen)度應(ying)力(li)而引(yin)起管(guan)(guan)(guan)(guan)道(dao)變(bian)形(xing)或破壞(huai)，需要在(zai)管(guan)(guan)(guan)(guan)道(dao)上設置補(bu)償器(qi)，以補(bu)償管(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱(re)伸長，從而減小管(guan)(guan)(guan)(guan)壁的(de)(de)應(ying)力(li)和作用(yong)(yong)在(zai)閥(fa)件(jian)或支架結(jie)構上的(de)(de)作用(yong)(yong)力(li)。