膨脹節(jie)習慣(guan)上(shang)也(ye)叫(jiao)補(bu)償(chang)(chang)器(qi)(qi)(qi)，或(huo)(huo)伸(shen)縮節(jie)。由構成其工(gong)作主體的(de)(de)波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(一種彈性(xing)元件)和(he)(he)端管(guan)(guan)(guan)(guan)(guan)(guan)(guan)、支(zhi)架、法蘭、導(dao)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)等附件組成。 膨脹節(jie)是為了補(bu)償(chang)(chang)因溫度差與機械振動引起(qi)的(de)(de)附加應(ying)力(li)，而(er)設置(zhi)在容(rong)器(qi)(qi)(qi)殼體或(huo)(huo)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道上(shang)的(de)(de)一種撓性(xing)結(jie)構。利用(yong)其工(gong)作主體波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)有效伸(shen)縮變(bian)形(xing)，以吸(xi)收管(guan)(guan)(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)(qi)(qi)等由熱(re)脹冷縮等原(yuan)因而(er)產生(sheng)的(de)(de)尺寸變(bian)化，或(huo)(huo)補(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)(qi)(qi)等的(de)(de)軸向(xiang)、橫向(xiang)和(he)(he)角向(xiang)位移。也(ye)可用(yong)于降(jiang)噪減振。供熱(re)上(shang)，為了防止供熱(re)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道升溫時，由于熱(re)伸(shen)長(chang)或(huo)(huo)溫度應(ying)力(li)而(er)引起(qi)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道變(bian)形(xing)或(huo)(huo)破壞(huai)，需要在管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道上(shang)設置(zhi)補(bu)償(chang)(chang)器(qi)(qi)(qi)，以補(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道的(de)(de)熱(re)伸(shen)長(chang)，從而(er)減小(xiao)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)壁的(de)(de)應(ying)力(li)和(he)(he)作用(yong)在閥件或(huo)(huo)支(zhi)架結(jie)構上(shang)的(de)(de)作用(yong)力(li)。