補(bu)償(chang)(chang)器(qi)(qi)習慣上(shang)也叫膨脹節，或(huo)(huo)伸(shen)縮節。由(you)構成其(qi)工(gong)作主(zhu)體(ti)的(de)(de)波紋管(guan)(guan)(guan)(guan)(guan)（一種彈性元(yuan)件(jian)）和(he)端管(guan)(guan)(guan)(guan)(guan)、支架、法蘭(lan)、導(dao)管(guan)(guan)(guan)(guan)(guan)等(deng)附件(jian)組成。 屬于一種補(bu)償(chang)(chang)元(yuan)件(jian)。利用(yong)其(qi)工(gong)作主(zhu)體(ti)波紋管(guan)(guan)(guan)(guan)(guan)的(de)(de)有效伸(shen)縮變形(xing)，以吸收管(guan)(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)(qi)等(deng)由(you)熱脹冷縮等(deng)原因而(er)(er)產生的(de)(de)尺寸變化，或(huo)(huo)補(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)(qi)等(deng)的(de)(de)軸向(xiang)、橫向(xiang)和(he)角向(xiang)位移。也可用(yong)于降噪減振。在現代(dai)工(gong)業中用(yong)途廣(guang)泛。供熱上(shang)，為了防止供熱管(guan)(guan)(guan)(guan)(guan)道(dao)升溫時(shi)，由(you)于熱伸(shen)長或(huo)(huo)溫度(du)應力而(er)(er)引起管(guan)(guan)(guan)(guan)(guan)道(dao)變形(xing)或(huo)(huo)破壞(huai)，需要(yao)在管(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)設置補(bu)償(chang)(chang)器(qi)(qi)，以補(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱伸(shen)長，從而(er)(er)減小管(guan)(guan)(guan)(guan)(guan)壁的(de)(de)應力和(he)作用(yong)在閥(fa)件(jian)或(huo)(huo)支架結(jie)構上(shang)的(de)(de)作用(yong)力。