補(bu)償(chang)器(qi)習慣上也叫(jiao)膨脹節(jie)，或伸(shen)縮節(jie)。由(you)(you)構成其工作(zuo)主體的(de)(de)波紋(wen)管(guan)(guan)(guan)(guan)（一種(zhong)彈性元(yuan)件(jian)(jian)）和端管(guan)(guan)(guan)(guan)、支架(jia)、法蘭、導(dao)(dao)管(guan)(guan)(guan)(guan)等(deng)(deng)附件(jian)(jian)組成。 屬于一種(zhong)補(bu)償(chang)元(yuan)件(jian)(jian)。利(li)用(yong)其工作(zuo)主體波紋(wen)管(guan)(guan)(guan)(guan)的(de)(de)有效伸(shen)縮變(bian)形，以吸收(shou)管(guan)(guan)(guan)(guan)線、導(dao)(dao)管(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)(deng)由(you)(you)熱(re)脹冷(leng)縮等(deng)(deng)原因而產生(sheng)的(de)(de)尺寸變(bian)化，或補(bu)償(chang)管(guan)(guan)(guan)(guan)線、導(dao)(dao)管(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)(deng)的(de)(de)軸向(xiang)、橫向(xiang)和角向(xiang)位移。也可用(yong)于降噪減振。在現代工業中(zhong)用(yong)途廣(guang)泛。供(gong)熱(re)上，為了防止供(gong)熱(re)管(guan)(guan)(guan)(guan)道(dao)升溫時(shi)，由(you)(you)于熱(re)伸(shen)長或溫度(du)應(ying)力而引起管(guan)(guan)(guan)(guan)道(dao)變(bian)形或破壞，需要在管(guan)(guan)(guan)(guan)道(dao)上設置(zhi)補(bu)償(chang)器(qi)，以補(bu)償(chang)管(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱(re)伸(shen)長，從而減小管(guan)(guan)(guan)(guan)壁的(de)(de)應(ying)力和作(zuo)用(yong)在閥件(jian)(jian)或支架(jia)結構上的(de)(de)作(zuo)用(yong)力。