膨脹節習慣上(shang)(shang)也叫補(bu)償(chang)器，或伸(shen)(shen)縮節。由(you)構(gou)(gou)成(cheng)其(qi)工作(zuo)(zuo)主體(ti)的(de)(de)(de)波(bo)紋管(guan)(guan)(guan)(guan)(guan)(一種(zhong)彈性(xing)元件(jian)(jian))和端管(guan)(guan)(guan)(guan)(guan)、支(zhi)架(jia)、法(fa)蘭、導(dao)管(guan)(guan)(guan)(guan)(guan)等(deng)附(fu)件(jian)(jian)組成(cheng)。 膨脹節是為(wei)了(le)補(bu)償(chang)因溫(wen)度(du)差與機械振(zhen)動引起的(de)(de)(de)附(fu)加應(ying)力，而(er)設置在容(rong)器殼體(ti)或管(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)的(de)(de)(de)一種(zhong)撓性(xing)結構(gou)(gou)。利用其(qi)工作(zuo)(zuo)主體(ti)波(bo)紋管(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)有效伸(shen)(shen)縮變(bian)(bian)形，以吸(xi)收管(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)、容(rong)器等(deng)由(you)熱(re)脹冷縮等(deng)原因而(er)產(chan)生的(de)(de)(de)尺寸(cun)變(bian)(bian)化(hua)，或補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)、容(rong)器等(deng)的(de)(de)(de)軸向、橫向和角向位移。也可(ke)用于(yu)(yu)降噪減振(zhen)。供熱(re)上(shang)(shang)，為(wei)了(le)防止(zhi)供熱(re)管(guan)(guan)(guan)(guan)(guan)道(dao)升溫(wen)時，由(you)于(yu)(yu)熱(re)伸(shen)(shen)長或溫(wen)度(du)應(ying)力而(er)引起管(guan)(guan)(guan)(guan)(guan)道(dao)變(bian)(bian)形或破壞，需(xu)要在管(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)設置補(bu)償(chang)器，以補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)道(dao)的(de)(de)(de)熱(re)伸(shen)(shen)長，從而(er)減小管(guan)(guan)(guan)(guan)(guan)壁(bi)的(de)(de)(de)應(ying)力和作(zuo)(zuo)用在閥(fa)件(jian)(jian)或支(zhi)架(jia)結構(gou)(gou)上(shang)(shang)的(de)(de)(de)作(zuo)(zuo)用力。