膨脹節習慣上(shang)(shang)也叫(jiao)補(bu)償(chang)(chang)(chang)器(qi)，或(huo)(huo)伸縮(suo)節。由(you)(you)構(gou)(gou)成其工(gong)(gong)作主體的(de)(de)波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)(一種彈性(xing)(xing)元件)和(he)端管(guan)(guan)(guan)(guan)(guan)、支架、法(fa)蘭(lan)、導(dao)管(guan)(guan)(guan)(guan)(guan)等附件組成。 膨脹節是為(wei)了(le)補(bu)償(chang)(chang)(chang)因(yin)溫度(du)差與機(ji)械振動引起(qi)的(de)(de)附加(jia)應力(li)，而設置(zhi)在容器(qi)殼體或(huo)(huo)管(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)的(de)(de)一種撓性(xing)(xing)結構(gou)(gou)。利用(yong)(yong)其工(gong)(gong)作主體波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)的(de)(de)有(you)效(xiao)伸縮(suo)變(bian)形(xing)，以(yi)吸收管(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)、容器(qi)等由(you)(you)熱(re)脹冷縮(suo)等原因(yin)而產生(sheng)的(de)(de)尺寸變(bian)化(hua)，或(huo)(huo)補(bu)償(chang)(chang)(chang)管(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)、容器(qi)等的(de)(de)軸向、橫向和(he)角(jiao)向位移。也可(ke)用(yong)(yong)于降噪減振。供(gong)熱(re)上(shang)(shang)，為(wei)了(le)防止供(gong)熱(re)管(guan)(guan)(guan)(guan)(guan)道(dao)升溫時，由(you)(you)于熱(re)伸長或(huo)(huo)溫度(du)應力(li)而引起(qi)管(guan)(guan)(guan)(guan)(guan)道(dao)變(bian)形(xing)或(huo)(huo)破壞，需要在管(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)設置(zhi)補(bu)償(chang)(chang)(chang)器(qi)，以(yi)補(bu)償(chang)(chang)(chang)管(guan)(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱(re)伸長，從而減小(xiao)管(guan)(guan)(guan)(guan)(guan)壁(bi)的(de)(de)應力(li)和(he)作用(yong)(yong)在閥件或(huo)(huo)支架結構(gou)(gou)上(shang)(shang)的(de)(de)作用(yong)(yong)力(li)。