補(bu)(bu)償(chang)器(qi)習慣上(shang)也叫膨脹節，或伸縮節。由(you)(you)(you)構(gou)成其工作(zuo)主體的(de)波紋管(guan)(guan)(guan)(guan)(guan)(guan)（一(yi)種(zhong)彈(dan)性元件）和端管(guan)(guan)(guan)(guan)(guan)(guan)、支(zhi)架(jia)、法蘭、導管(guan)(guan)(guan)(guan)(guan)(guan)等(deng)附件組成。 屬于一(yi)種(zhong)補(bu)(bu)償(chang)元件。利(li)用(yong)其工作(zuo)主體波紋管(guan)(guan)(guan)(guan)(guan)(guan)的(de)有(you)效伸縮變(bian)形，以吸(xi)收管(guan)(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)(rong)器(qi)等(deng)由(you)(you)(you)熱(re)脹冷縮等(deng)原因而(er)產生(sheng)的(de)尺寸變(bian)化(hua)，或補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)(rong)器(qi)等(deng)的(de)軸向、橫向和角向位移。也可用(yong)于降(jiang)噪減(jian)振(zhen)。在現代工業中用(yong)途廣(guang)泛。供(gong)熱(re)上(shang)，為了防止(zhi)供(gong)熱(re)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)升(sheng)溫時，由(you)(you)(you)于熱(re)伸長或溫度(du)應力而(er)引起管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)變(bian)形或破(po)壞，需要(yao)在管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)設置補(bu)(bu)償(chang)器(qi)，以補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)的(de)熱(re)伸長，從而(er)減(jian)小管(guan)(guan)(guan)(guan)(guan)(guan)壁的(de)應力和作(zuo)用(yong)在閥(fa)件或支(zhi)架(jia)結構(gou)上(shang)的(de)作(zuo)用(yong)力。