膨脹(zhang)節習(xi)慣上(shang)(shang)(shang)也叫(jiao)補償器，或(huo)(huo)伸縮節。由構成(cheng)其(qi)工(gong)作(zuo)主(zhu)體(ti)的(de)(de)(de)(de)波(bo)(bo)紋(wen)管(guan)(guan)(guan)(guan)(一種(zhong)彈性元(yuan)件(jian))和端管(guan)(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)(guan)等附(fu)(fu)件(jian)組成(cheng)。 膨脹(zhang)節是為(wei)(wei)了(le)(le)補償因溫(wen)(wen)度差與機械振動引起(qi)的(de)(de)(de)(de)附(fu)(fu)加應(ying)(ying)力，而設置(zhi)在容(rong)器殼體(ti)或(huo)(huo)管(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)(shang)的(de)(de)(de)(de)一種(zhong)撓性結構。利用其(qi)工(gong)作(zuo)主(zhu)體(ti)波(bo)(bo)紋(wen)管(guan)(guan)(guan)(guan)的(de)(de)(de)(de)有效伸縮變形(xing)，以吸收管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容(rong)器等由熱(re)脹(zhang)冷縮等原因而產生的(de)(de)(de)(de)尺(chi)寸變化(hua)，或(huo)(huo)補償管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容(rong)器等的(de)(de)(de)(de)軸向(xiang)、橫向(xiang)和角向(xiang)位移(yi)。也可用于降噪(zao)減振。供熱(re)上(shang)(shang)(shang)，為(wei)(wei)了(le)(le)防止供熱(re)管(guan)(guan)(guan)(guan)道(dao)升溫(wen)(wen)時，由于熱(re)伸長(chang)或(huo)(huo)溫(wen)(wen)度應(ying)(ying)力而引起(qi)管(guan)(guan)(guan)(guan)道(dao)變形(xing)或(huo)(huo)破壞，需(xu)要在管(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)(shang)設置(zhi)補償器，以補償管(guan)(guan)(guan)(guan)道(dao)的(de)(de)(de)(de)熱(re)伸長(chang)，從(cong)而減小(xiao)管(guan)(guan)(guan)(guan)壁的(de)(de)(de)(de)應(ying)(ying)力和作(zuo)用在閥件(jian)或(huo)(huo)支架結構上(shang)(shang)(shang)的(de)(de)(de)(de)作(zuo)用力。