補(bu)(bu)償器(qi)習慣上也叫膨脹(zhang)節，或伸(shen)(shen)縮(suo)節。由構(gou)成(cheng)其工(gong)(gong)作主體(ti)的波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)（一種彈性元(yuan)件(jian)(jian)）和(he)端管(guan)(guan)(guan)(guan)(guan)、支架(jia)、法(fa)蘭、導管(guan)(guan)(guan)(guan)(guan)等(deng)附件(jian)(jian)組成(cheng)。 屬于一種補(bu)(bu)償元(yuan)件(jian)(jian)。利用(yong)(yong)其工(gong)(gong)作主體(ti)波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)的有效伸(shen)(shen)縮(suo)變形(xing)，以吸(xi)收管(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)由熱(re)脹(zhang)冷縮(suo)等(deng)原因而產生(sheng)的尺(chi)寸變化，或補(bu)(bu)償管(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)的軸向(xiang)(xiang)、橫向(xiang)(xiang)和(he)角向(xiang)(xiang)位移。也可用(yong)(yong)于降噪減振。在現代工(gong)(gong)業中用(yong)(yong)途(tu)廣泛。供(gong)熱(re)上，為了防止供(gong)熱(re)管(guan)(guan)(guan)(guan)(guan)道(dao)升溫時，由于熱(re)伸(shen)(shen)長或溫度應(ying)力而引起管(guan)(guan)(guan)(guan)(guan)道(dao)變形(xing)或破壞，需要在管(guan)(guan)(guan)(guan)(guan)道(dao)上設置補(bu)(bu)償器(qi)，以補(bu)(bu)償管(guan)(guan)(guan)(guan)(guan)道(dao)的熱(re)伸(shen)(shen)長，從而減小(xiao)管(guan)(guan)(guan)(guan)(guan)壁的應(ying)力和(he)作用(yong)(yong)在閥件(jian)(jian)或支架(jia)結構(gou)上的作用(yong)(yong)力。