補(bu)償(chang)(chang)器(qi)(qi)習慣上也(ye)叫膨脹節，或(huo)伸縮節。由(you)構成(cheng)其(qi)工作主體(ti)的波紋(wen)管(guan)(guan)(guan)(guan)（一種彈(dan)性元(yuan)件(jian)）和(he)端管(guan)(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)(guan)等附件(jian)組成(cheng)。 屬于一種補(bu)償(chang)(chang)元(yuan)件(jian)。利用其(qi)工作主體(ti)波紋(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)(qi)等由(you)熱脹冷縮等原因而產生的尺寸(cun)變(bian)化，或(huo)補(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)(qi)等的軸向(xiang)、橫向(xiang)和(he)角向(xiang)位(wei)移。也(ye)可用于降噪(zao)減(jian)振。在現代工業中用途廣泛。供(gong)熱上，為了防止供(gong)熱管(guan)(guan)(guan)(guan)道(dao)(dao)升溫時，由(you)于熱伸長或(huo)溫度應(ying)力(li)而引(yin)起(qi)管(guan)(guan)(guan)(guan)道(dao)(dao)變(bian)形(xing)或(huo)破(po)壞，需要在管(guan)(guan)(guan)(guan)道(dao)(dao)上設置補(bu)償(chang)(chang)器(qi)(qi)，以補(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)道(dao)(dao)的熱伸長，從而減(jian)小管(guan)(guan)(guan)(guan)壁的應(ying)力(li)和(he)作用在閥(fa)件(jian)或(huo)支架結構上的作用力(li)。