膨脹節習慣上(shang)(shang)(shang)也叫補(bu)償(chang)器(qi)(qi)(qi)，或(huo)伸(shen)縮(suo)節。由構成其(qi)工作(zuo)主(zhu)體(ti)的波紋(wen)管(guan)(guan)(guan)(guan)(一種彈(dan)性(xing)元(yuan)件(jian)(jian))和(he)端管(guan)(guan)(guan)(guan)、支(zhi)架、法蘭(lan)、導管(guan)(guan)(guan)(guan)等(deng)(deng)附件(jian)(jian)組(zu)成。 膨脹節是(shi)為(wei)了補(bu)償(chang)因溫(wen)度差與機械振動(dong)引(yin)起(qi)的附加應力，而(er)設(she)置在(zai)容器(qi)(qi)(qi)殼體(ti)或(huo)管(guan)(guan)(guan)(guan)道(dao)(dao)上(shang)(shang)(shang)的一種撓性(xing)結構。利(li)用(yong)(yong)其(qi)工作(zuo)主(zhu)體(ti)波紋(wen)管(guan)(guan)(guan)(guan)的有效伸(shen)縮(suo)變形(xing)，以(yi)吸收(shou)管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)(qi)(qi)等(deng)(deng)由熱脹冷縮(suo)等(deng)(deng)原因而(er)產生的尺寸(cun)變化(hua)，或(huo)補(bu)償(chang)管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)(qi)(qi)等(deng)(deng)的軸向、橫向和(he)角向位移。也可(ke)用(yong)(yong)于降噪減(jian)振。供(gong)熱上(shang)(shang)(shang)，為(wei)了防止供(gong)熱管(guan)(guan)(guan)(guan)道(dao)(dao)升溫(wen)時，由于熱伸(shen)長(chang)或(huo)溫(wen)度應力而(er)引(yin)起(qi)管(guan)(guan)(guan)(guan)道(dao)(dao)變形(xing)或(huo)破壞(huai)，需要在(zai)管(guan)(guan)(guan)(guan)道(dao)(dao)上(shang)(shang)(shang)設(she)置補(bu)償(chang)器(qi)(qi)(qi)，以(yi)補(bu)償(chang)管(guan)(guan)(guan)(guan)道(dao)(dao)的熱伸(shen)長(chang)，從而(er)減(jian)小管(guan)(guan)(guan)(guan)壁的應力和(he)作(zuo)用(yong)(yong)在(zai)閥件(jian)(jian)或(huo)支(zhi)架結構上(shang)(shang)(shang)的作(zuo)用(yong)(yong)力。