補(bu)(bu)償(chang)(chang)器(qi)習(xi)慣(guan)上(shang)(shang)也叫(jiao)膨脹(zhang)節(jie)，或(huo)伸(shen)縮(suo)節(jie)。由(you)構成(cheng)其(qi)(qi)工作主(zhu)體的(de)波紋管(guan)(guan)（一種(zhong)彈性(xing)元件(jian)）和(he)端管(guan)(guan)、支架、法蘭、導管(guan)(guan)等附件(jian)組成(cheng)。 屬于(yu)一種(zhong)補(bu)(bu)償(chang)(chang)元件(jian)。利(li)用(yong)(yong)(yong)其(qi)(qi)工作主(zhu)體波紋管(guan)(guan)的(de)有效伸(shen)縮(suo)變形，以吸收管(guan)(guan)線、導管(guan)(guan)、容(rong)器(qi)等由(you)熱(re)脹(zhang)冷縮(suo)等原因而(er)產生(sheng)的(de)尺寸變化，或(huo)補(bu)(bu)償(chang)(chang)管(guan)(guan)線、導管(guan)(guan)、容(rong)器(qi)等的(de)軸向、橫向和(he)角(jiao)向位移。也可用(yong)(yong)(yong)于(yu)降噪減(jian)振。在現代(dai)工業中用(yong)(yong)(yong)途廣(guang)泛(fan)。供(gong)(gong)熱(re)上(shang)(shang)，為(wei)了(le)防止供(gong)(gong)熱(re)管(guan)(guan)道(dao)(dao)升溫時(shi)，由(you)于(yu)熱(re)伸(shen)長(chang)或(huo)溫度應力而(er)引起管(guan)(guan)道(dao)(dao)變形或(huo)破壞(huai)，需(xu)要在管(guan)(guan)道(dao)(dao)上(shang)(shang)設(she)置補(bu)(bu)償(chang)(chang)器(qi)，以補(bu)(bu)償(chang)(chang)管(guan)(guan)道(dao)(dao)的(de)熱(re)伸(shen)長(chang)，從而(er)減(jian)小管(guan)(guan)壁的(de)應力和(he)作用(yong)(yong)(yong)在閥件(jian)或(huo)支架結構上(shang)(shang)的(de)作用(yong)(yong)(yong)力。