補(bu)(bu)償器(qi)(qi)習慣上(shang)(shang)(shang)也叫膨(peng)脹節，或(huo)伸縮節。由(you)構(gou)成(cheng)(cheng)其(qi)工作主體的(de)(de)波(bo)紋(wen)管(guan)(guan)(guan)(guan)（一(yi)種(zhong)彈(dan)性元(yuan)件）和端(duan)管(guan)(guan)(guan)(guan)、支架、法蘭、導(dao)管(guan)(guan)(guan)(guan)等(deng)(deng)附件組成(cheng)(cheng)。 屬于一(yi)種(zhong)補(bu)(bu)償元(yuan)件。利用(yong)(yong)其(qi)工作主體波(bo)紋(wen)管(guan)(guan)(guan)(guan)的(de)(de)有效伸縮變形，以吸收管(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)、容(rong)(rong)器(qi)(qi)等(deng)(deng)由(you)熱(re)(re)(re)脹冷縮等(deng)(deng)原因而產生的(de)(de)尺(chi)寸變化，或(huo)補(bu)(bu)償管(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)、容(rong)(rong)器(qi)(qi)等(deng)(deng)的(de)(de)軸向、橫(heng)向和角(jiao)向位移(yi)。也可用(yong)(yong)于降噪減振。在(zai)現代工業中用(yong)(yong)途廣泛。供(gong)熱(re)(re)(re)上(shang)(shang)(shang)，為了防(fang)止供(gong)熱(re)(re)(re)管(guan)(guan)(guan)(guan)道(dao)升溫時，由(you)于熱(re)(re)(re)伸長或(huo)溫度應力(li)而引起管(guan)(guan)(guan)(guan)道(dao)變形或(huo)破壞，需要在(zai)管(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)(shang)設置補(bu)(bu)償器(qi)(qi)，以補(bu)(bu)償管(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱(re)(re)(re)伸長，從而減小(xiao)管(guan)(guan)(guan)(guan)壁的(de)(de)應力(li)和作用(yong)(yong)在(zai)閥(fa)件或(huo)支架結構(gou)上(shang)(shang)(shang)的(de)(de)作用(yong)(yong)力(li)。