補償器習慣上也叫膨脹節，或伸縮節。由構成其工作主體的波紋管（一種彈性元件）和端管、支架、法蘭、導管等附件組成。膨脹節廠家 屬于一種補(bu)(bu)償(chang)元件。利用(yong)其工作主體波紋管(guan)(guan)(guan)(guan)的(de)(de)有效伸縮(suo)變(bian)形，以吸收(shou)管(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)、容(rong)(rong)器等(deng)由熱(re)脹冷(leng)縮(suo)等(deng)原因(yin)而產(chan)生(sheng)的(de)(de)尺寸變(bian)化，或(huo)補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)、容(rong)(rong)器等(deng)的(de)(de)軸向(xiang)、橫向(xiang)和角向(xiang)位(wei)移。也(ye)可(ke)用(yong)于降(jiang)噪減振(zhen)。在現代(dai)工業中用(yong)途廣泛。供(gong)熱(re)上(shang)，為了防止供(gong)熱(re)管(guan)(guan)(guan)(guan)道(dao)(dao)升溫(wen)時，由于熱(re)伸長或(huo)溫(wen)度應(ying)力而引起管(guan)(guan)(guan)(guan)道(dao)(dao)變(bian)形或(huo)破壞，需要在管(guan)(guan)(guan)(guan)道(dao)(dao)上(shang)設(she)置(zhi)補(bu)(bu)償(chang)器，以補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)道(dao)(dao)的(de)(de)熱(re)伸長，從而減小管(guan)(guan)(guan)(guan)壁的(de)(de)應(ying)力和作用(yong)在閥件或(huo)支架結(jie)構上(shang)的(de)(de)作用(yong)力。