補(bu)償(chang)器(qi)習慣上(shang)也叫膨(peng)脹節，或(huo)伸縮(suo)節。由(you)構成(cheng)其(qi)工作主體(ti)的波紋管(guan)(guan)（一種彈性元件）和(he)端管(guan)(guan)、支架、法蘭、導管(guan)(guan)等附件組成(cheng)。 屬于一種補(bu)償(chang)元件。利用(yong)(yong)(yong)其(qi)工作主體(ti)波紋管(guan)(guan)的有效伸縮(suo)變(bian)形(xing)，以吸收管(guan)(guan)線、導管(guan)(guan)、容器(qi)等由(you)熱(re)(re)(re)脹冷(leng)縮(suo)等原因(yin)而(er)產生的尺寸變(bian)化，或(huo)補(bu)償(chang)管(guan)(guan)線、導管(guan)(guan)、容器(qi)等的軸向、橫向和(he)角向位移。也可(ke)用(yong)(yong)(yong)于降噪減振(zhen)。在現(xian)代工業中用(yong)(yong)(yong)途(tu)廣泛。供(gong)(gong)熱(re)(re)(re)上(shang)，為了防止(zhi)供(gong)(gong)熱(re)(re)(re)管(guan)(guan)道(dao)升溫(wen)(wen)時，由(you)于熱(re)(re)(re)伸長或(huo)溫(wen)(wen)度(du)應力而(er)引起管(guan)(guan)道(dao)變(bian)形(xing)或(huo)破壞(huai)，需要在管(guan)(guan)道(dao)上(shang)設置補(bu)償(chang)器(qi)，以補(bu)償(chang)管(guan)(guan)道(dao)的熱(re)(re)(re)伸長，從而(er)減小管(guan)(guan)壁(bi)的應力和(he)作用(yong)(yong)(yong)在閥(fa)件或(huo)支架結(jie)構上(shang)的作用(yong)(yong)(yong)力。