膨脹(zhang)節習慣(guan)上也叫補(bu)償(chang)器，或(huo)(huo)伸縮(suo)節。由(you)構成(cheng)其工(gong)(gong)作(zuo)主(zhu)體(ti)的(de)(de)(de)波(bo)紋(wen)管(guan)(guan)(guan)(guan)(一(yi)種(zhong)彈性(xing)元(yuan)件)和端(duan)管(guan)(guan)(guan)(guan)、支架、法(fa)蘭、導管(guan)(guan)(guan)(guan)等(deng)(deng)附件組成(cheng)。 膨脹(zhang)節是為(wei)了補(bu)償(chang)因(yin)溫(wen)度(du)差與機械振動引起(qi)的(de)(de)(de)附加應(ying)力，而(er)(er)設(she)置在(zai)容器殼體(ti)或(huo)(huo)管(guan)(guan)(guan)(guan)道(dao)(dao)上的(de)(de)(de)一(yi)種(zhong)撓性(xing)結構。利用(yong)(yong)其工(gong)(gong)作(zuo)主(zhu)體(ti)波(bo)紋(wen)管(guan)(guan)(guan)(guan)的(de)(de)(de)有效(xiao)伸縮(suo)變形(xing)，以吸(xi)收管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器等(deng)(deng)由(you)熱(re)(re)脹(zhang)冷縮(suo)等(deng)(deng)原(yuan)因(yin)而(er)(er)產生的(de)(de)(de)尺寸變化，或(huo)(huo)補(bu)償(chang)管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器等(deng)(deng)的(de)(de)(de)軸向、橫向和角向位移。也可(ke)用(yong)(yong)于降噪減(jian)振。供熱(re)(re)上，為(wei)了防止供熱(re)(re)管(guan)(guan)(guan)(guan)道(dao)(dao)升溫(wen)時，由(you)于熱(re)(re)伸長(chang)或(huo)(huo)溫(wen)度(du)應(ying)力而(er)(er)引起(qi)管(guan)(guan)(guan)(guan)道(dao)(dao)變形(xing)或(huo)(huo)破(po)壞(huai)，需(xu)要在(zai)管(guan)(guan)(guan)(guan)道(dao)(dao)上設(she)置補(bu)償(chang)器，以補(bu)償(chang)管(guan)(guan)(guan)(guan)道(dao)(dao)的(de)(de)(de)熱(re)(re)伸長(chang)，從而(er)(er)減(jian)小管(guan)(guan)(guan)(guan)壁的(de)(de)(de)應(ying)力和作(zuo)用(yong)(yong)在(zai)閥(fa)件或(huo)(huo)支架結構上的(de)(de)(de)作(zuo)用(yong)(yong)力。