補償(chang)器習慣上也叫膨脹節，或(huo)(huo)伸(shen)縮(suo)節。由構(gou)成(cheng)其(qi)工作主體的(de)(de)波紋管(guan)(guan)(guan)(guan)（一種彈性元(yuan)件(jian)(jian)）和端管(guan)(guan)(guan)(guan)、支架(jia)、法蘭、導(dao)管(guan)(guan)(guan)(guan)等附件(jian)(jian)組成(cheng)。 屬于一種補償(chang)元(yuan)件(jian)(jian)。利用(yong)(yong)其(qi)工作主體波紋管(guan)(guan)(guan)(guan)的(de)(de)有效伸(shen)縮(suo)變(bian)形，以吸收管(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)、容器等由熱(re)(re)脹冷縮(suo)等原因而(er)產(chan)生(sheng)的(de)(de)尺寸(cun)變(bian)化(hua)，或(huo)(huo)補償(chang)管(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)、容器等的(de)(de)軸向、橫向和角(jiao)向位移。也可(ke)用(yong)(yong)于降噪減(jian)振。在(zai)現代工業中用(yong)(yong)途(tu)廣泛。供熱(re)(re)上，為了防止供熱(re)(re)管(guan)(guan)(guan)(guan)道(dao)升溫時(shi)，由于熱(re)(re)伸(shen)長或(huo)(huo)溫度(du)應力而(er)引起管(guan)(guan)(guan)(guan)道(dao)變(bian)形或(huo)(huo)破(po)壞，需要在(zai)管(guan)(guan)(guan)(guan)道(dao)上設置補償(chang)器，以補償(chang)管(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱(re)(re)伸(shen)長，從而(er)減(jian)小管(guan)(guan)(guan)(guan)壁的(de)(de)應力和作用(yong)(yong)在(zai)閥件(jian)(jian)或(huo)(huo)支架(jia)結構(gou)上的(de)(de)作用(yong)(yong)力。