膨脹(zhang)節習慣上(shang)(shang)也叫補(bu)償(chang)器(qi)(qi)，或(huo)伸縮節。由(you)構(gou)成(cheng)其工作主(zhu)體(ti)的(de)(de)(de)(de)波紋(wen)管(guan)(guan)(guan)(guan)(guan)(一種彈性元件(jian))和(he)端管(guan)(guan)(guan)(guan)(guan)、支架、法蘭、導(dao)管(guan)(guan)(guan)(guan)(guan)等(deng)附件(jian)組(zu)成(cheng)。 膨脹(zhang)節是為了(le)補(bu)償(chang)因(yin)溫(wen)度差與機(ji)械(xie)振動引(yin)起的(de)(de)(de)(de)附加應力，而設置在容器(qi)(qi)殼體(ti)或(huo)管(guan)(guan)(guan)(guan)(guan)道上(shang)(shang)的(de)(de)(de)(de)一種撓性結構(gou)。利用(yong)其工作主(zhu)體(ti)波紋(wen)管(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)有效伸縮變(bian)形，以吸收管(guan)(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)由(you)熱(re)脹(zhang)冷(leng)縮等(deng)原因(yin)而產生的(de)(de)(de)(de)尺寸(cun)變(bian)化(hua)，或(huo)補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)的(de)(de)(de)(de)軸向、橫向和(he)角向位移。也可用(yong)于降噪(zao)減振。供熱(re)上(shang)(shang)，為了(le)防止供熱(re)管(guan)(guan)(guan)(guan)(guan)道升溫(wen)時，由(you)于熱(re)伸長或(huo)溫(wen)度應力而引(yin)起管(guan)(guan)(guan)(guan)(guan)道變(bian)形或(huo)破(po)壞，需要(yao)在管(guan)(guan)(guan)(guan)(guan)道上(shang)(shang)設置補(bu)償(chang)器(qi)(qi)，以補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)道的(de)(de)(de)(de)熱(re)伸長，從而減小管(guan)(guan)(guan)(guan)(guan)壁的(de)(de)(de)(de)應力和(he)作用(yong)在閥件(jian)或(huo)支架結構(gou)上(shang)(shang)的(de)(de)(de)(de)作用(yong)力。