補償(chang)器(qi)(qi)習慣上(shang)也(ye)叫膨脹(zhang)節，或(huo)伸縮節。由構成其工作主體的(de)(de)波(bo)紋管(guan)(guan)(guan)(guan)(guan)（一種(zhong)(zhong)彈性元(yuan)件）和端管(guan)(guan)(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)(guan)(guan)等(deng)附件組成。 屬于一種(zhong)(zhong)補償(chang)元(yuan)件。利(li)用(yong)(yong)其工作主體波(bo)紋管(guan)(guan)(guan)(guan)(guan)的(de)(de)有(you)效(xiao)伸縮變形(xing)，以(yi)吸收管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)由熱(re)(re)(re)脹(zhang)冷縮等(deng)原因而產生的(de)(de)尺寸變化，或(huo)補償(chang)管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)的(de)(de)軸向、橫向和角向位移。也(ye)可用(yong)(yong)于降噪減振。在現代(dai)工業中用(yong)(yong)途廣泛(fan)。供(gong)熱(re)(re)(re)上(shang)，為(wei)了防止供(gong)熱(re)(re)(re)管(guan)(guan)(guan)(guan)(guan)道升溫時，由于熱(re)(re)(re)伸長(chang)或(huo)溫度應力而引(yin)起管(guan)(guan)(guan)(guan)(guan)道變形(xing)或(huo)破壞，需要在管(guan)(guan)(guan)(guan)(guan)道上(shang)設置補償(chang)器(qi)(qi)，以(yi)補償(chang)管(guan)(guan)(guan)(guan)(guan)道的(de)(de)熱(re)(re)(re)伸長(chang)，從而減小(xiao)管(guan)(guan)(guan)(guan)(guan)壁的(de)(de)應力和作用(yong)(yong)在閥件或(huo)支架結構上(shang)的(de)(de)作用(yong)(yong)力。