補(bu)償(chang)器(qi)習(xi)慣上(shang)(shang)(shang)也叫膨脹節，或(huo)伸縮節。由(you)構成(cheng)(cheng)其(qi)工作主(zhu)體(ti)(ti)的(de)(de)(de)波紋管(guan)(guan)(guan)（一(yi)種(zhong)彈性元(yuan)件）和(he)端管(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)等(deng)附件組成(cheng)(cheng)。 屬于一(yi)種(zhong)補(bu)償(chang)元(yuan)件。利用(yong)(yong)其(qi)工作主(zhu)體(ti)(ti)波紋管(guan)(guan)(guan)的(de)(de)(de)有(you)效(xiao)伸縮變(bian)形，以(yi)吸(xi)收(shou)管(guan)(guan)(guan)線(xian)(xian)、導管(guan)(guan)(guan)、容(rong)器(qi)等(deng)由(you)熱(re)脹冷(leng)縮等(deng)原因而產生的(de)(de)(de)尺寸變(bian)化，或(huo)補(bu)償(chang)管(guan)(guan)(guan)線(xian)(xian)、導管(guan)(guan)(guan)、容(rong)器(qi)等(deng)的(de)(de)(de)軸向、橫(heng)向和(he)角向位移。也可(ke)用(yong)(yong)于降噪減振。在(zai)現(xian)代工業中用(yong)(yong)途(tu)廣泛(fan)。供熱(re)上(shang)(shang)(shang)，為了防止供熱(re)管(guan)(guan)(guan)道升(sheng)溫時(shi)，由(you)于熱(re)伸長或(huo)溫度應(ying)力而引起管(guan)(guan)(guan)道變(bian)形或(huo)破壞，需要在(zai)管(guan)(guan)(guan)道上(shang)(shang)(shang)設置補(bu)償(chang)器(qi)，以(yi)補(bu)償(chang)管(guan)(guan)(guan)道的(de)(de)(de)熱(re)伸長，從而減小(xiao)管(guan)(guan)(guan)壁的(de)(de)(de)應(ying)力和(he)作用(yong)(yong)在(zai)閥件或(huo)支架結構上(shang)(shang)(shang)的(de)(de)(de)作用(yong)(yong)力。