補(bu)償器習慣上(shang)也叫膨脹節，或(huo)(huo)伸縮節。由構成(cheng)其(qi)(qi)工(gong)(gong)作(zuo)主(zhu)(zhu)體(ti)的(de)波紋管(guan)(guan)（一(yi)種彈(dan)性(xing)元(yuan)件）和端(duan)管(guan)(guan)、支(zhi)架、法蘭、導(dao)(dao)管(guan)(guan)等(deng)(deng)附件組成(cheng)。 屬于一(yi)種補(bu)償元(yuan)件。利用(yong)(yong)(yong)其(qi)(qi)工(gong)(gong)作(zuo)主(zhu)(zhu)體(ti)波紋管(guan)(guan)的(de)有效伸縮變形(xing)，以(yi)吸(xi)收管(guan)(guan)線、導(dao)(dao)管(guan)(guan)、容器等(deng)(deng)由熱脹冷縮等(deng)(deng)原(yuan)因而產生的(de)尺寸(cun)變化，或(huo)(huo)補(bu)償管(guan)(guan)線、導(dao)(dao)管(guan)(guan)、容器等(deng)(deng)的(de)軸向、橫(heng)向和角向位(wei)移。也可用(yong)(yong)(yong)于降噪減振。在現代工(gong)(gong)業中用(yong)(yong)(yong)途廣泛。供熱上(shang)，為了防止供熱管(guan)(guan)道(dao)升溫時，由于熱伸長或(huo)(huo)溫度(du)應力(li)(li)而引起管(guan)(guan)道(dao)變形(xing)或(huo)(huo)破(po)壞(huai)，需要在管(guan)(guan)道(dao)上(shang)設(she)置補(bu)償器，以(yi)補(bu)償管(guan)(guan)道(dao)的(de)熱伸長，從而減小管(guan)(guan)壁的(de)應力(li)(li)和作(zuo)用(yong)(yong)(yong)在閥件或(huo)(huo)支(zhi)架結構上(shang)的(de)作(zuo)用(yong)(yong)(yong)力(li)(li)。