補(bu)償器(qi)(qi)習慣上(shang)也叫膨脹節，或(huo)(huo)伸縮節。由(you)構成其工(gong)(gong)作主體的波(bo)紋(wen)管(guan)(guan)(guan)(guan)（一(yi)種(zhong)彈性元(yuan)件(jian)）和(he)端(duan)管(guan)(guan)(guan)(guan)、支架(jia)、法蘭(lan)、導管(guan)(guan)(guan)(guan)等附件(jian)組成。 屬于一(yi)種(zhong)補(bu)償元(yuan)件(jian)。利(li)用(yong)(yong)(yong)其工(gong)(gong)作主體波(bo)紋(wen)管(guan)(guan)(guan)(guan)的有效伸縮變(bian)形，以吸收管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)(qi)等由(you)熱(re)脹冷縮等原(yuan)因(yin)而產生的尺寸變(bian)化，或(huo)(huo)補(bu)償管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)(qi)等的軸(zhou)向、橫(heng)向和(he)角向位(wei)移。也可用(yong)(yong)(yong)于降噪減振。在現代(dai)工(gong)(gong)業中用(yong)(yong)(yong)途(tu)廣泛。供(gong)熱(re)上(shang)，為了(le)防(fang)止供(gong)熱(re)管(guan)(guan)(guan)(guan)道升(sheng)溫(wen)時，由(you)于熱(re)伸長(chang)或(huo)(huo)溫(wen)度(du)應(ying)力而引起管(guan)(guan)(guan)(guan)道變(bian)形或(huo)(huo)破壞(huai)，需要在管(guan)(guan)(guan)(guan)道上(shang)設置補(bu)償器(qi)(qi)，以補(bu)償管(guan)(guan)(guan)(guan)道的熱(re)伸長(chang)，從而減小管(guan)(guan)(guan)(guan)壁的應(ying)力和(he)作用(yong)(yong)(yong)在閥(fa)件(jian)或(huo)(huo)支架(jia)結構上(shang)的作用(yong)(yong)(yong)力。