膨(peng)脹(zhang)節(jie)習慣上(shang)也叫補(bu)(bu)償器，或(huo)(huo)伸(shen)縮(suo)節(jie)。由構成其(qi)工作(zuo)(zuo)主體的(de)(de)波紋(wen)(wen)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(一種彈性(xing)元件)和端管(guan)(guan)(guan)(guan)(guan)(guan)(guan)、支架(jia)、法蘭、導管(guan)(guan)(guan)(guan)(guan)(guan)(guan)等(deng)附(fu)件組成。 膨(peng)脹(zhang)節(jie)是為(wei)了補(bu)(bu)償因(yin)溫度(du)(du)差與機械振(zhen)動引(yin)起的(de)(de)附(fu)加應力，而(er)設(she)置在容器殼體或(huo)(huo)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)的(de)(de)一種撓性(xing)結(jie)構。利用(yong)(yong)(yong)(yong)其(qi)工作(zuo)(zuo)主體波紋(wen)(wen)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)有(you)效伸(shen)縮(suo)變形(xing)，以吸收管(guan)(guan)(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)(guan)(guan)、容器等(deng)由熱脹(zhang)冷縮(suo)等(deng)原因(yin)而(er)產生的(de)(de)尺寸變化，或(huo)(huo)補(bu)(bu)償管(guan)(guan)(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)(guan)(guan)、容器等(deng)的(de)(de)軸向、橫(heng)向和角向位移。也可用(yong)(yong)(yong)(yong)于降噪減(jian)振(zhen)。供(gong)熱上(shang)，為(wei)了防止供(gong)熱管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道(dao)升溫時，由于熱伸(shen)長(chang)或(huo)(huo)溫度(du)(du)應力而(er)引(yin)起管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道(dao)變形(xing)或(huo)(huo)破壞，需要在管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)設(she)置補(bu)(bu)償器，以補(bu)(bu)償管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱伸(shen)長(chang)，從而(er)減(jian)小管(guan)(guan)(guan)(guan)(guan)(guan)(guan)壁的(de)(de)應力和作(zuo)(zuo)用(yong)(yong)(yong)(yong)在閥(fa)件或(huo)(huo)支架(jia)結(jie)構上(shang)的(de)(de)作(zuo)(zuo)用(yong)(yong)(yong)(yong)力。