膨脹(zhang)節習慣上(shang)也叫(jiao)補(bu)償器(qi)(qi)，或伸(shen)(shen)縮節。由(you)構成其工(gong)作主體(ti)的(de)波(bo)紋管(guan)(guan)(guan)(guan)(一(yi)種彈(dan)性元件(jian))和端管(guan)(guan)(guan)(guan)、支架(jia)、法蘭(lan)、導管(guan)(guan)(guan)(guan)等(deng)(deng)(deng)附件(jian)組成。 膨脹(zhang)節是為(wei)了補(bu)償因溫(wen)度差與機械振(zhen)動(dong)引起(qi)的(de)附加應力(li)，而設置在(zai)容器(qi)(qi)殼(ke)體(ti)或管(guan)(guan)(guan)(guan)道(dao)上(shang)的(de)一(yi)種撓性結構。利用(yong)(yong)其工(gong)作主體(ti)波(bo)紋管(guan)(guan)(guan)(guan)的(de)有效伸(shen)(shen)縮變形，以吸收管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)(deng)(deng)由(you)熱脹(zhang)冷縮等(deng)(deng)(deng)原因而產生的(de)尺寸變化(hua)，或補(bu)償管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)(deng)(deng)的(de)軸向、橫向和角向位移。也可(ke)用(yong)(yong)于降(jiang)噪減振(zhen)。供(gong)熱上(shang)，為(wei)了防止供(gong)熱管(guan)(guan)(guan)(guan)道(dao)升溫(wen)時，由(you)于熱伸(shen)(shen)長或溫(wen)度應力(li)而引起(qi)管(guan)(guan)(guan)(guan)道(dao)變形或破壞，需要在(zai)管(guan)(guan)(guan)(guan)道(dao)上(shang)設置補(bu)償器(qi)(qi)，以補(bu)償管(guan)(guan)(guan)(guan)道(dao)的(de)熱伸(shen)(shen)長，從而減小管(guan)(guan)(guan)(guan)壁的(de)應力(li)和作用(yong)(yong)在(zai)閥(fa)件(jian)或支架(jia)結構上(shang)的(de)作用(yong)(yong)力(li)。