膨脹節(jie)習慣上(shang)也叫(jiao)補(bu)(bu)(bu)償(chang)器，或(huo)(huo)(huo)伸(shen)(shen)縮節(jie)。由構成(cheng)(cheng)其工作(zuo)(zuo)主體(ti)(ti)的(de)波紋管(guan)(guan)(guan)(一種(zhong)彈性元(yuan)件(jian))和端(duan)管(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)等(deng)(deng)附(fu)(fu)件(jian)組成(cheng)(cheng)。 膨脹節(jie)是(shi)為了補(bu)(bu)(bu)償(chang)因溫(wen)度差與機械振(zhen)動引起的(de)附(fu)(fu)加(jia)應力(li)，而(er)設置(zhi)在容(rong)(rong)器殼體(ti)(ti)或(huo)(huo)(huo)管(guan)(guan)(guan)道(dao)上(shang)的(de)一種(zhong)撓性結構。利用(yong)(yong)其工作(zuo)(zuo)主體(ti)(ti)波紋管(guan)(guan)(guan)的(de)有效伸(shen)(shen)縮變形(xing)，以吸收(shou)管(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)、容(rong)(rong)器等(deng)(deng)由熱脹冷縮等(deng)(deng)原因而(er)產(chan)生的(de)尺寸變化，或(huo)(huo)(huo)補(bu)(bu)(bu)償(chang)管(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)、容(rong)(rong)器等(deng)(deng)的(de)軸向、橫向和角向位移。也可用(yong)(yong)于降噪減(jian)(jian)振(zhen)。供(gong)熱上(shang)，為了防止供(gong)熱管(guan)(guan)(guan)道(dao)升溫(wen)時，由于熱伸(shen)(shen)長(chang)或(huo)(huo)(huo)溫(wen)度應力(li)而(er)引起管(guan)(guan)(guan)道(dao)變形(xing)或(huo)(huo)(huo)破壞，需要在管(guan)(guan)(guan)道(dao)上(shang)設置(zhi)補(bu)(bu)(bu)償(chang)器，以補(bu)(bu)(bu)償(chang)管(guan)(guan)(guan)道(dao)的(de)熱伸(shen)(shen)長(chang)，從而(er)減(jian)(jian)小管(guan)(guan)(guan)壁的(de)應力(li)和作(zuo)(zuo)用(yong)(yong)在閥件(jian)或(huo)(huo)(huo)支架結構上(shang)的(de)作(zuo)(zuo)用(yong)(yong)力(li)。