補償器習慣上也叫膨脹節，或伸縮節。由構成其工作主體的波紋管（一種彈性元件）和端管、支架、法蘭、導管等附件組成。膨脹節廠家 屬(shu)于一種補償(chang)元件(jian)(jian)。利用(yong)其工作主體波紋管(guan)(guan)(guan)(guan)的有效伸(shen)縮變(bian)形，以吸收管(guan)(guan)(guan)(guan)線(xian)(xian)、導(dao)管(guan)(guan)(guan)(guan)、容器等(deng)由熱脹冷縮等(deng)原(yuan)因而(er)(er)產生(sheng)的尺寸變(bian)化(hua)，或(huo)補償(chang)管(guan)(guan)(guan)(guan)線(xian)(xian)、導(dao)管(guan)(guan)(guan)(guan)、容器等(deng)的軸向、橫向和(he)角向位移。也(ye)可用(yong)于降(jiang)噪減(jian)振。在現代工業中用(yong)途廣(guang)泛。供熱上，為(wei)了(le)防(fang)止(zhi)供熱管(guan)(guan)(guan)(guan)道(dao)(dao)(dao)升溫時，由于熱伸(shen)長(chang)(chang)或(huo)溫度應力而(er)(er)引起管(guan)(guan)(guan)(guan)道(dao)(dao)(dao)變(bian)形或(huo)破壞(huai)，需要在管(guan)(guan)(guan)(guan)道(dao)(dao)(dao)上設置補償(chang)器，以補償(chang)管(guan)(guan)(guan)(guan)道(dao)(dao)(dao)的熱伸(shen)長(chang)(chang)，從而(er)(er)減(jian)小管(guan)(guan)(guan)(guan)壁的應力和(he)作用(yong)在閥件(jian)(jian)或(huo)支(zhi)架結構(gou)上的作用(yong)力。