膨(peng)脹(zhang)節(jie)習慣(guan)上(shang)也(ye)叫補(bu)償(chang)器(qi)(qi)，或(huo)伸(shen)縮節(jie)。由(you)構(gou)成其(qi)工作主體的(de)(de)(de)波(bo)紋管(guan)(guan)(guan)(guan)(guan)(guan)(一種彈性元(yuan)件(jian))和端(duan)管(guan)(guan)(guan)(guan)(guan)(guan)、支(zhi)架(jia)、法蘭、導管(guan)(guan)(guan)(guan)(guan)(guan)等附件(jian)組成。 膨(peng)脹(zhang)節(jie)是為了補(bu)償(chang)因(yin)溫(wen)度(du)差與機械振(zhen)(zhen)動引起(qi)的(de)(de)(de)附加應力，而(er)(er)設置在(zai)容(rong)(rong)器(qi)(qi)殼體或(huo)管(guan)(guan)(guan)(guan)(guan)(guan)道上(shang)的(de)(de)(de)一種撓(nao)性結構(gou)。利用其(qi)工作主體波(bo)紋管(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)有效伸(shen)縮變(bian)形(xing)，以吸(xi)收管(guan)(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)(rong)器(qi)(qi)等由(you)熱脹(zhang)冷縮等原因(yin)而(er)(er)產生的(de)(de)(de)尺寸(cun)變(bian)化(hua)，或(huo)補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)(rong)器(qi)(qi)等的(de)(de)(de)軸向(xiang)、橫向(xiang)和角向(xiang)位移。也(ye)可(ke)用于(yu)降噪減(jian)(jian)振(zhen)(zhen)。供熱上(shang)，為了防止供熱管(guan)(guan)(guan)(guan)(guan)(guan)道升溫(wen)時，由(you)于(yu)熱伸(shen)長或(huo)溫(wen)度(du)應力而(er)(er)引起(qi)管(guan)(guan)(guan)(guan)(guan)(guan)道變(bian)形(xing)或(huo)破壞(huai)，需要(yao)在(zai)管(guan)(guan)(guan)(guan)(guan)(guan)道上(shang)設置補(bu)償(chang)器(qi)(qi)，以補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)道的(de)(de)(de)熱伸(shen)長，從(cong)而(er)(er)減(jian)(jian)小管(guan)(guan)(guan)(guan)(guan)(guan)壁(bi)的(de)(de)(de)應力和作用在(zai)閥件(jian)或(huo)支(zhi)架(jia)結構(gou)上(shang)的(de)(de)(de)作用力。