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)償元件。利用(yong)(yong)其工作主(zhu)體波(bo)紋管(guan)(guan)(guan)(guan)的(de)有效(xiao)伸(shen)縮變(bian)形(xing)，以吸(xi)收管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器等(deng)(deng)由熱脹冷縮等(deng)(deng)原因而(er)(er)產(chan)生的(de)尺(chi)寸變(bian)化(hua)，或補(bu)償管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器等(deng)(deng)的(de)軸向、橫向和(he)角向位移。也(ye)可用(yong)(yong)于降噪(zao)減(jian)振。在現代工業中用(yong)(yong)途廣泛。供熱上，為了防(fang)止(zhi)供熱管(guan)(guan)(guan)(guan)道(dao)(dao)升(sheng)溫(wen)時，由于熱伸(shen)長(chang)或溫(wen)度(du)應力而(er)(er)引起管(guan)(guan)(guan)(guan)道(dao)(dao)變(bian)形(xing)或破壞，需要在管(guan)(guan)(guan)(guan)道(dao)(dao)上設置(zhi)補(bu)償器，以補(bu)償管(guan)(guan)(guan)(guan)道(dao)(dao)的(de)熱伸(shen)長(chang)，從而(er)(er)減(jian)小管(guan)(guan)(guan)(guan)壁的(de)應力和(he)作用(yong)(yong)在閥件或支架(jia)結構(gou)上的(de)作用(yong)(yong)力。