補(bu)償器(qi)習慣上(shang)也(ye)叫膨脹節，或(huo)(huo)(huo)伸縮節。由構成(cheng)其(qi)工作(zuo)(zuo)主(zhu)體(ti)的波(bo)紋(wen)管(guan)(guan)(guan)(guan)（一種彈性元件(jian)(jian)）和端(duan)管(guan)(guan)(guan)(guan)、支(zhi)(zhi)架、法蘭、導管(guan)(guan)(guan)(guan)等附件(jian)(jian)組成(cheng)。 屬于(yu)一種補(bu)償元件(jian)(jian)。利用(yong)其(qi)工作(zuo)(zuo)主(zhu)體(ti)波(bo)紋(wen)管(guan)(guan)(guan)(guan)的有效伸縮變(bian)形(xing)，以吸收管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)等由熱脹冷縮等原因而產生的尺寸變(bian)化(hua)，或(huo)(huo)(huo)補(bu)償管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)等的軸向(xiang)、橫向(xiang)和角向(xiang)位移。也(ye)可用(yong)于(yu)降噪(zao)減(jian)振。在(zai)現(xian)代(dai)工業(ye)中用(yong)途廣泛。供熱上(shang)，為(wei)了(le)防止(zhi)供熱管(guan)(guan)(guan)(guan)道升溫時，由于(yu)熱伸長或(huo)(huo)(huo)溫度應力而引起管(guan)(guan)(guan)(guan)道變(bian)形(xing)或(huo)(huo)(huo)破壞，需要在(zai)管(guan)(guan)(guan)(guan)道上(shang)設置(zhi)補(bu)償器(qi)，以補(bu)償管(guan)(guan)(guan)(guan)道的熱伸長，從而減(jian)小管(guan)(guan)(guan)(guan)壁的應力和作(zuo)(zuo)用(yong)在(zai)閥件(jian)(jian)或(huo)(huo)(huo)支(zhi)(zhi)架結構上(shang)的作(zuo)(zuo)用(yong)力。