膨(peng)脹(zhang)節(jie)習(xi)慣上也叫補(bu)(bu)償(chang)(chang)器(qi)(qi)(qi)(qi)，或(huo)(huo)伸(shen)縮(suo)節(jie)。由構(gou)成(cheng)其工(gong)(gong)作主體(ti)的(de)(de)波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)(一種彈性(xing)元件)和端(duan)管(guan)(guan)(guan)(guan)(guan)、支架(jia)、法(fa)蘭、導(dao)管(guan)(guan)(guan)(guan)(guan)等(deng)附件組成(cheng)。 膨(peng)脹(zhang)節(jie)是為(wei)了補(bu)(bu)償(chang)(chang)因(yin)溫度差與機(ji)械(xie)振動引起的(de)(de)附加應(ying)力，而(er)(er)設置(zhi)在(zai)(zai)容(rong)(rong)器(qi)(qi)(qi)(qi)殼體(ti)或(huo)(huo)管(guan)(guan)(guan)(guan)(guan)道(dao)上的(de)(de)一種撓性(xing)結構(gou)。利用(yong)其工(gong)(gong)作主體(ti)波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)的(de)(de)有效伸(shen)縮(suo)變(bian)(bian)形(xing)，以(yi)吸收(shou)管(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)、容(rong)(rong)器(qi)(qi)(qi)(qi)等(deng)由熱脹(zhang)冷縮(suo)等(deng)原(yuan)因(yin)而(er)(er)產(chan)生的(de)(de)尺寸變(bian)(bian)化，或(huo)(huo)補(bu)(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)、容(rong)(rong)器(qi)(qi)(qi)(qi)等(deng)的(de)(de)軸向、橫向和角向位移(yi)。也可用(yong)于降噪減(jian)振。供(gong)熱上，為(wei)了防止供(gong)熱管(guan)(guan)(guan)(guan)(guan)道(dao)升溫時，由于熱伸(shen)長或(huo)(huo)溫度應(ying)力而(er)(er)引起管(guan)(guan)(guan)(guan)(guan)道(dao)變(bian)(bian)形(xing)或(huo)(huo)破壞，需要在(zai)(zai)管(guan)(guan)(guan)(guan)(guan)道(dao)上設置(zhi)補(bu)(bu)償(chang)(chang)器(qi)(qi)(qi)(qi)，以(yi)補(bu)(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱伸(shen)長，從而(er)(er)減(jian)小(xiao)管(guan)(guan)(guan)(guan)(guan)壁(bi)的(de)(de)應(ying)力和作用(yong)在(zai)(zai)閥件或(huo)(huo)支架(jia)結構(gou)上的(de)(de)作用(yong)力。