膨脹(zhang)節習慣上(shang)也叫補(bu)償(chang)器(qi)(qi)，或伸(shen)縮節。由構(gou)成(cheng)其工(gong)(gong)作(zuo)主體的(de)(de)波紋(wen)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、法蘭(lan)、導管(guan)(guan)(guan)(guan)(guan)(guan)等(deng)附(fu)件(jian)組成(cheng)。 膨脹(zhang)節是為(wei)了補(bu)償(chang)因溫度(du)差(cha)與(yu)機械振動引(yin)起(qi)的(de)(de)附(fu)加應力(li)，而(er)設置(zhi)在容(rong)(rong)器(qi)(qi)殼(ke)體或管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)的(de)(de)一種撓性結(jie)構(gou)。利用其工(gong)(gong)作(zuo)主體波紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)有效伸(shen)縮變(bian)形(xing)，以(yi)吸收管(guan)(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)(rong)器(qi)(qi)等(deng)由熱(re)脹(zhang)冷縮等(deng)原因而(er)產生的(de)(de)尺寸變(bian)化，或補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)(rong)器(qi)(qi)等(deng)的(de)(de)軸向(xiang)、橫向(xiang)和角向(xiang)位移。也可用于降噪(zao)減振。供熱(re)上(shang)，為(wei)了防(fang)止供熱(re)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)升溫時，由于熱(re)伸(shen)長(chang)或溫度(du)應力(li)而(er)引(yin)起(qi)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)變(bian)形(xing)或破(po)壞(huai)，需(xu)要(yao)在管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)設置(zhi)補(bu)償(chang)器(qi)(qi)，以(yi)補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱(re)伸(shen)長(chang)，從而(er)減小管(guan)(guan)(guan)(guan)(guan)(guan)壁的(de)(de)應力(li)和作(zuo)用在閥件(jian)或支(zhi)架結(jie)構(gou)上(shang)的(de)(de)作(zuo)用力(li)。