補(bu)償(chang)器(qi)習慣(guan)上(shang)也叫膨脹節，或伸(shen)縮節。由構成其(qi)工作主體的波紋管(guan)(guan)(guan)（一(yi)種彈性元件(jian)）和(he)(he)端管(guan)(guan)(guan)、支架、法蘭、導(dao)管(guan)(guan)(guan)等附件(jian)組成。 屬于(yu)一(yi)種補(bu)償(chang)元件(jian)。利用(yong)(yong)其(qi)工作主體波紋管(guan)(guan)(guan)的有(you)效(xiao)伸(shen)縮變(bian)(bian)形(xing)(xing)，以吸收管(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)、容器(qi)等由熱(re)(re)脹冷縮等原因而產生的尺寸(cun)變(bian)(bian)化，或補(bu)償(chang)管(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)、容器(qi)等的軸向(xiang)、橫向(xiang)和(he)(he)角(jiao)向(xiang)位移。也可(ke)用(yong)(yong)于(yu)降噪減(jian)振。在(zai)現代工業中用(yong)(yong)途廣(guang)泛。供熱(re)(re)上(shang)，為了防止供熱(re)(re)管(guan)(guan)(guan)道(dao)升溫時，由于(yu)熱(re)(re)伸(shen)長(chang)或溫度應力而引起管(guan)(guan)(guan)道(dao)變(bian)(bian)形(xing)(xing)或破壞，需(xu)要(yao)在(zai)管(guan)(guan)(guan)道(dao)上(shang)設置(zhi)補(bu)償(chang)器(qi)，以補(bu)償(chang)管(guan)(guan)(guan)道(dao)的熱(re)(re)伸(shen)長(chang)，從而減(jian)小管(guan)(guan)(guan)壁的應力和(he)(he)作用(yong)(yong)在(zai)閥件(jian)或支架結構上(shang)的作用(yong)(yong)力。