膨脹節習慣(guan)上(shang)(shang)(shang)也叫補償器(qi)，或(huo)伸(shen)(shen)縮(suo)節。由構成其(qi)(qi)工作主體(ti)的(de)(de)(de)波(bo)紋(wen)管(guan)(guan)(guan)(guan)(一種彈性元件(jian)(jian))和端管(guan)(guan)(guan)(guan)、支(zhi)架、法蘭、導(dao)管(guan)(guan)(guan)(guan)等附(fu)件(jian)(jian)組成。 膨脹節是為了補償因(yin)溫(wen)度(du)差與機械振(zhen)動引起的(de)(de)(de)附(fu)加應(ying)力(li)(li)，而設置在容(rong)(rong)(rong)器(qi)殼體(ti)或(huo)管(guan)(guan)(guan)(guan)道上(shang)(shang)(shang)的(de)(de)(de)一種撓性結(jie)構。利用(yong)其(qi)(qi)工作主體(ti)波(bo)紋(wen)管(guan)(guan)(guan)(guan)的(de)(de)(de)有效伸(shen)(shen)縮(suo)變形，以吸(xi)收管(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)、容(rong)(rong)(rong)器(qi)等由熱脹冷縮(suo)等原因(yin)而產生的(de)(de)(de)尺寸變化，或(huo)補償管(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)、容(rong)(rong)(rong)器(qi)等的(de)(de)(de)軸向(xiang)(xiang)、橫(heng)向(xiang)(xiang)和角向(xiang)(xiang)位移。也可(ke)用(yong)于(yu)降噪減振(zhen)。供熱上(shang)(shang)(shang)，為了防止供熱管(guan)(guan)(guan)(guan)道升溫(wen)時，由于(yu)熱伸(shen)(shen)長或(huo)溫(wen)度(du)應(ying)力(li)(li)而引起管(guan)(guan)(guan)(guan)道變形或(huo)破壞，需(xu)要(yao)在管(guan)(guan)(guan)(guan)道上(shang)(shang)(shang)設置補償器(qi)，以補償管(guan)(guan)(guan)(guan)道的(de)(de)(de)熱伸(shen)(shen)長，從而減小管(guan)(guan)(guan)(guan)壁的(de)(de)(de)應(ying)力(li)(li)和作用(yong)在閥件(jian)(jian)或(huo)支(zhi)架結(jie)構上(shang)(shang)(shang)的(de)(de)(de)作用(yong)力(li)(li)。