補償器習慣上(shang)也叫膨脹節，或(huo)(huo)伸縮(suo)節。由構(gou)成其(qi)工作(zuo)主(zhu)(zhu)體(ti)的(de)(de)波紋(wen)(wen)管(guan)(guan)(guan)(guan)（一種彈(dan)性元件）和(he)端管(guan)(guan)(guan)(guan)、支架、法蘭(lan)、導(dao)(dao)管(guan)(guan)(guan)(guan)等附件組成。 屬于一種補償元件。利用(yong)(yong)其(qi)工作(zuo)主(zhu)(zhu)體(ti)波紋(wen)(wen)管(guan)(guan)(guan)(guan)的(de)(de)有效伸縮(suo)變(bian)(bian)形(xing)(xing)，以吸收管(guan)(guan)(guan)(guan)線(xian)、導(dao)(dao)管(guan)(guan)(guan)(guan)、容(rong)器等由熱脹冷(leng)縮(suo)等原因(yin)而(er)(er)產生(sheng)的(de)(de)尺(chi)寸(cun)變(bian)(bian)化，或(huo)(huo)補償管(guan)(guan)(guan)(guan)線(xian)、導(dao)(dao)管(guan)(guan)(guan)(guan)、容(rong)器等的(de)(de)軸向(xiang)、橫(heng)向(xiang)和(he)角(jiao)向(xiang)位移。也可用(yong)(yong)于降噪減振(zhen)。在(zai)現代工業中用(yong)(yong)途(tu)廣泛。供熱上(shang)，為了防(fang)止供熱管(guan)(guan)(guan)(guan)道升(sheng)溫時，由于熱伸長或(huo)(huo)溫度應力而(er)(er)引(yin)起管(guan)(guan)(guan)(guan)道變(bian)(bian)形(xing)(xing)或(huo)(huo)破(po)壞，需要(yao)在(zai)管(guan)(guan)(guan)(guan)道上(shang)設置補償器，以補償管(guan)(guan)(guan)(guan)道的(de)(de)熱伸長，從(cong)而(er)(er)減小(xiao)管(guan)(guan)(guan)(guan)壁的(de)(de)應力和(he)作(zuo)用(yong)(yong)在(zai)閥件或(huo)(huo)支架結構(gou)上(shang)的(de)(de)作(zuo)用(yong)(yong)力。