補(bu)(bu)償器(qi)(qi)習慣(guan)上也(ye)叫膨脹節，或(huo)伸(shen)(shen)縮節。由構成(cheng)其(qi)工(gong)(gong)作主(zhu)體的(de)(de)波紋管(guan)(guan)(guan)（一種彈性(xing)元件）和端管(guan)(guan)(guan)、支架、法蘭(lan)、導管(guan)(guan)(guan)等附(fu)件組成(cheng)。 屬于(yu)一種補(bu)(bu)償元件。利用(yong)(yong)其(qi)工(gong)(gong)作主(zhu)體波紋管(guan)(guan)(guan)的(de)(de)有(you)效伸(shen)(shen)縮變形，以吸(xi)收管(guan)(guan)(guan)線、導管(guan)(guan)(guan)、容器(qi)(qi)等由熱(re)脹冷縮等原(yuan)因而產生(sheng)的(de)(de)尺(chi)寸變化，或(huo)補(bu)(bu)償管(guan)(guan)(guan)線、導管(guan)(guan)(guan)、容器(qi)(qi)等的(de)(de)軸向(xiang)、橫向(xiang)和角(jiao)向(xiang)位(wei)移(yi)。也(ye)可用(yong)(yong)于(yu)降噪減(jian)振。在(zai)現(xian)代(dai)工(gong)(gong)業中用(yong)(yong)途廣(guang)泛(fan)。供(gong)熱(re)上，為(wei)了防止供(gong)熱(re)管(guan)(guan)(guan)道升溫時，由于(yu)熱(re)伸(shen)(shen)長或(huo)溫度應力而引起管(guan)(guan)(guan)道變形或(huo)破壞(huai)，需(xu)要在(zai)管(guan)(guan)(guan)道上設置補(bu)(bu)償器(qi)(qi)，以補(bu)(bu)償管(guan)(guan)(guan)道的(de)(de)熱(re)伸(shen)(shen)長，從而減(jian)小管(guan)(guan)(guan)壁的(de)(de)應力和作用(yong)(yong)在(zai)閥件或(huo)支架結構上的(de)(de)作用(yong)(yong)力。