補(bu)(bu)(bu)償(chang)(chang)器(qi)(qi)習慣(guan)上(shang)也叫膨脹節，或(huo)(huo)伸縮(suo)節。由構成其(qi)工(gong)作主體的(de)(de)(de)波紋管(guan)(guan)(guan)(guan)（一種(zhong)(zhong)彈性元(yuan)件）和端管(guan)(guan)(guan)(guan)、支(zhi)(zhi)架、法蘭、導(dao)管(guan)(guan)(guan)(guan)等(deng)(deng)附件組成。 屬于一種(zhong)(zhong)補(bu)(bu)(bu)償(chang)(chang)元(yuan)件。利用(yong)(yong)(yong)其(qi)工(gong)作主體波紋管(guan)(guan)(guan)(guan)的(de)(de)(de)有效伸縮(suo)變(bian)形，以(yi)吸收(shou)管(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)(deng)由熱(re)脹冷縮(suo)等(deng)(deng)原因(yin)而(er)(er)產(chan)生的(de)(de)(de)尺寸變(bian)化，或(huo)(huo)補(bu)(bu)(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)(deng)的(de)(de)(de)軸向、橫(heng)向和角向位移。也可用(yong)(yong)(yong)于降噪減(jian)振。在(zai)(zai)現代(dai)工(gong)業中用(yong)(yong)(yong)途廣泛。供熱(re)上(shang)，為了防止供熱(re)管(guan)(guan)(guan)(guan)道(dao)升溫時，由于熱(re)伸長或(huo)(huo)溫度應力而(er)(er)引起(qi)管(guan)(guan)(guan)(guan)道(dao)變(bian)形或(huo)(huo)破壞，需要在(zai)(zai)管(guan)(guan)(guan)(guan)道(dao)上(shang)設置補(bu)(bu)(bu)償(chang)(chang)器(qi)(qi)，以(yi)補(bu)(bu)(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)道(dao)的(de)(de)(de)熱(re)伸長，從而(er)(er)減(jian)小管(guan)(guan)(guan)(guan)壁的(de)(de)(de)應力和作用(yong)(yong)(yong)在(zai)(zai)閥(fa)件或(huo)(huo)支(zhi)(zhi)架結構上(shang)的(de)(de)(de)作用(yong)(yong)(yong)力。