膨脹(zhang)節(jie)(jie)習慣上(shang)(shang)也叫補(bu)(bu)償(chang)器(qi)，或(huo)(huo)伸縮節(jie)(jie)。由構成其工(gong)作(zuo)主體(ti)(ti)的(de)波紋管(guan)(guan)(guan)(guan)(guan)(一(yi)種彈性元件)和端管(guan)(guan)(guan)(guan)(guan)、支(zhi)架(jia)、法蘭、導管(guan)(guan)(guan)(guan)(guan)等(deng)附件組成。 膨脹(zhang)節(jie)(jie)是為了補(bu)(bu)償(chang)因溫度差與(yu)機(ji)械振(zhen)動引起的(de)附加(jia)應力(li)，而(er)(er)設置在容(rong)器(qi)殼體(ti)(ti)或(huo)(huo)管(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)的(de)一(yi)種撓性結構。利用(yong)(yong)其工(gong)作(zuo)主體(ti)(ti)波紋管(guan)(guan)(guan)(guan)(guan)的(de)有效(xiao)伸縮變形(xing)，以吸收管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)由熱(re)(re)(re)脹(zhang)冷(leng)縮等(deng)原因而(er)(er)產生的(de)尺(chi)寸變化，或(huo)(huo)補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)的(de)軸向(xiang)、橫向(xiang)和角向(xiang)位(wei)移。也可(ke)用(yong)(yong)于(yu)降噪(zao)減(jian)振(zhen)。供(gong)熱(re)(re)(re)上(shang)(shang)，為了防止供(gong)熱(re)(re)(re)管(guan)(guan)(guan)(guan)(guan)道(dao)升溫時(shi)，由于(yu)熱(re)(re)(re)伸長或(huo)(huo)溫度應力(li)而(er)(er)引起管(guan)(guan)(guan)(guan)(guan)道(dao)變形(xing)或(huo)(huo)破壞，需(xu)要在管(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)設置補(bu)(bu)償(chang)器(qi)，以補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)道(dao)的(de)熱(re)(re)(re)伸長，從而(er)(er)減(jian)小管(guan)(guan)(guan)(guan)(guan)壁(bi)的(de)應力(li)和作(zuo)用(yong)(yong)在閥件或(huo)(huo)支(zhi)架(jia)結構上(shang)(shang)的(de)作(zuo)用(yong)(yong)力(li)。