膨脹節(jie)習慣上(shang)也叫補(bu)(bu)償(chang)(chang)器，或(huo)伸(shen)縮節(jie)。由(you)構成(cheng)其(qi)工(gong)(gong)作(zuo)主體的(de)(de)波紋管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(一種彈性(xing)(xing)元件(jian))和端(duan)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)、支(zhi)架、法蘭、導管(guan)(guan)(guan)(guan)(guan)(guan)(guan)等附(fu)件(jian)組(zu)成(cheng)。 膨脹節(jie)是為(wei)了補(bu)(bu)償(chang)(chang)因溫(wen)度差與機械(xie)振(zhen)動引起的(de)(de)附(fu)加(jia)應(ying)力(li)(li)，而(er)(er)設置在(zai)(zai)容器殼(ke)體或(huo)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道上(shang)的(de)(de)一種撓性(xing)(xing)結構。利(li)用其(qi)工(gong)(gong)作(zuo)主體波紋管(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)有效伸(shen)縮變(bian)(bian)形，以吸收管(guan)(guan)(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)(guan)(guan)、容器等由(you)熱脹冷縮等原(yuan)因而(er)(er)產生的(de)(de)尺寸變(bian)(bian)化，或(huo)補(bu)(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)(guan)(guan)、容器等的(de)(de)軸向(xiang)、橫向(xiang)和角向(xiang)位移。也可用于降(jiang)噪減振(zhen)。供熱上(shang)，為(wei)了防止供熱管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道升溫(wen)時，由(you)于熱伸(shen)長或(huo)溫(wen)度應(ying)力(li)(li)而(er)(er)引起管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道變(bian)(bian)形或(huo)破壞，需要在(zai)(zai)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道上(shang)設置補(bu)(bu)償(chang)(chang)器，以補(bu)(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道的(de)(de)熱伸(shen)長，從而(er)(er)減小(xiao)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)壁(bi)的(de)(de)應(ying)力(li)(li)和作(zuo)用在(zai)(zai)閥件(jian)或(huo)支(zhi)架結構上(shang)的(de)(de)作(zuo)用力(li)(li)。