膨脹(zhang)節習慣上也叫補償器，或(huo)(huo)伸(shen)縮節。由構(gou)成(cheng)其(qi)工作(zuo)主體的(de)波紋管(guan)(guan)(guan)(guan)(一(yi)種(zhong)彈性元件(jian))和端管(guan)(guan)(guan)(guan)、支(zhi)架、法蘭、導管(guan)(guan)(guan)(guan)等附件(jian)組(zu)成(cheng)。 膨脹(zhang)節是為(wei)了補償因溫度(du)(du)差(cha)與機械振(zhen)動(dong)引起的(de)附加應(ying)力，而設置在容(rong)器殼體或(huo)(huo)管(guan)(guan)(guan)(guan)道上的(de)一(yi)種(zhong)撓性結構(gou)。利(li)用(yong)(yong)其(qi)工作(zuo)主體波紋管(guan)(guan)(guan)(guan)的(de)有效伸(shen)縮變(bian)形，以(yi)吸收(shou)管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容(rong)器等由熱脹(zhang)冷縮等原(yuan)因而產生的(de)尺寸變(bian)化，或(huo)(huo)補償管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容(rong)器等的(de)軸向、橫向和角向位移(yi)。也可用(yong)(yong)于降噪減振(zhen)。供(gong)熱上，為(wei)了防(fang)止(zhi)供(gong)熱管(guan)(guan)(guan)(guan)道升溫時，由于熱伸(shen)長或(huo)(huo)溫度(du)(du)應(ying)力而引起管(guan)(guan)(guan)(guan)道變(bian)形或(huo)(huo)破壞(huai)，需要在管(guan)(guan)(guan)(guan)道上設置補償器，以(yi)補償管(guan)(guan)(guan)(guan)道的(de)熱伸(shen)長，從而減小(xiao)管(guan)(guan)(guan)(guan)壁的(de)應(ying)力和作(zuo)用(yong)(yong)在閥件(jian)或(huo)(huo)支(zhi)架結構(gou)上的(de)作(zuo)用(yong)(yong)力。