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(yi)種補償元件。利(li)用(yong)其工(gong)作主體波紋管(guan)(guan)(guan)(guan)(guan)(guan)的(de)有(you)效伸(shen)縮變形(xing)(xing)，以吸收管(guan)(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)(guan)、容器等由熱(re)脹冷縮等原因而(er)產生的(de)尺寸變化，或(huo)補償管(guan)(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)(guan)、容器等的(de)軸向、橫向和角向位移(yi)。也可用(yong)于降(jiang)噪(zao)減振。在現代(dai)工(gong)業中用(yong)途廣(guang)泛。供(gong)熱(re)上，為(wei)了防止供(gong)熱(re)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)(dao)升溫(wen)時，由于熱(re)伸(shen)長或(huo)溫(wen)度(du)應力而(er)引起管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)(dao)變形(xing)(xing)或(huo)破(po)壞，需(xu)要在管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)(dao)上設置補償器，以補償管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)(dao)的(de)熱(re)伸(shen)長，從而(er)減小管(guan)(guan)(guan)(guan)(guan)(guan)壁的(de)應力和作用(yong)在閥(fa)件或(huo)支架結構上的(de)作用(yong)力。