膨脹節習慣上也(ye)叫補償器，或(huo)伸(shen)縮(suo)節。由(you)構(gou)成(cheng)其工(gong)作(zuo)(zuo)主體(ti)(ti)的波紋管(guan)(guan)(guan)(guan)(guan)(一(yi)種彈性(xing)元件)和(he)端管(guan)(guan)(guan)(guan)(guan)、支架、法蘭、導(dao)管(guan)(guan)(guan)(guan)(guan)等(deng)附件組成(cheng)。 膨脹節是為了補償因(yin)溫度差(cha)與機械振(zhen)動引起的附加應(ying)力(li)(li)，而設(she)置在(zai)容(rong)器殼(ke)體(ti)(ti)或(huo)管(guan)(guan)(guan)(guan)(guan)道(dao)上的一(yi)種撓性(xing)結構(gou)。利用其工(gong)作(zuo)(zuo)主體(ti)(ti)波紋管(guan)(guan)(guan)(guan)(guan)的有效伸(shen)縮(suo)變(bian)(bian)形，以(yi)吸收管(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)、容(rong)器等(deng)由(you)熱(re)(re)脹冷(leng)縮(suo)等(deng)原因(yin)而產生的尺寸變(bian)(bian)化，或(huo)補償管(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)、容(rong)器等(deng)的軸向、橫向和(he)角向位移(yi)。也(ye)可用于(yu)降(jiang)噪(zao)減(jian)(jian)振(zhen)。供(gong)熱(re)(re)上，為了防止供(gong)熱(re)(re)管(guan)(guan)(guan)(guan)(guan)道(dao)升溫時，由(you)于(yu)熱(re)(re)伸(shen)長(chang)或(huo)溫度應(ying)力(li)(li)而引起管(guan)(guan)(guan)(guan)(guan)道(dao)變(bian)(bian)形或(huo)破壞(huai)，需(xu)要在(zai)管(guan)(guan)(guan)(guan)(guan)道(dao)上設(she)置補償器，以(yi)補償管(guan)(guan)(guan)(guan)(guan)道(dao)的熱(re)(re)伸(shen)長(chang)，從而減(jian)(jian)小管(guan)(guan)(guan)(guan)(guan)壁的應(ying)力(li)(li)和(he)作(zuo)(zuo)用在(zai)閥件或(huo)支架結構(gou)上的作(zuo)(zuo)用力(li)(li)。