膨脹節(jie)(jie)習慣上(shang)(shang)也(ye)叫補(bu)償(chang)器，或伸(shen)縮(suo)節(jie)(jie)。由(you)構(gou)成其工(gong)作主體(ti)的波紋管(guan)(guan)(guan)(guan)(guan)(一種彈性(xing)元件)和端(duan)管(guan)(guan)(guan)(guan)(guan)、支架、法(fa)蘭、導管(guan)(guan)(guan)(guan)(guan)等(deng)附件組成。 膨脹節(jie)(jie)是(shi)為了補(bu)償(chang)因(yin)溫度差與(yu)機械振(zhen)動引起(qi)的附加應(ying)力，而(er)設置(zhi)在(zai)(zai)(zai)容(rong)器殼(ke)體(ti)或管(guan)(guan)(guan)(guan)(guan)道上(shang)(shang)的一種撓性(xing)結構(gou)。利用其工(gong)作主體(ti)波紋管(guan)(guan)(guan)(guan)(guan)的有(you)效伸(shen)縮(suo)變(bian)形(xing)，以吸(xi)收管(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)、容(rong)器等(deng)由(you)熱脹冷縮(suo)等(deng)原因(yin)而(er)產生的尺寸變(bian)化，或補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)、容(rong)器等(deng)的軸向、橫向和角向位移(yi)。也(ye)可用于(yu)降噪(zao)減振(zhen)。供(gong)熱上(shang)(shang)，為了防止供(gong)熱管(guan)(guan)(guan)(guan)(guan)道升溫時(shi)，由(you)于(yu)熱伸(shen)長或溫度應(ying)力而(er)引起(qi)管(guan)(guan)(guan)(guan)(guan)道變(bian)形(xing)或破(po)壞，需要在(zai)(zai)(zai)管(guan)(guan)(guan)(guan)(guan)道上(shang)(shang)設置(zhi)補(bu)償(chang)器，以補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)道的熱伸(shen)長，從而(er)減小管(guan)(guan)(guan)(guan)(guan)壁的應(ying)力和作用在(zai)(zai)(zai)閥件或支架結構(gou)上(shang)(shang)的作用力。