補(bu)(bu)償器(qi)(qi)習慣上也叫膨脹節，或伸縮(suo)(suo)節。由(you)(you)構(gou)成其(qi)工(gong)作(zuo)主體(ti)的波紋管(guan)(guan)(guan)（一種彈性元件(jian)）和端管(guan)(guan)(guan)、支(zhi)架(jia)、法蘭、導(dao)管(guan)(guan)(guan)等(deng)附(fu)件(jian)組成。 屬(shu)于一種補(bu)(bu)償元件(jian)。利用(yong)(yong)其(qi)工(gong)作(zuo)主體(ti)波紋管(guan)(guan)(guan)的有(you)效(xiao)伸縮(suo)(suo)變(bian)(bian)形(xing)，以(yi)吸收管(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)、容器(qi)(qi)等(deng)由(you)(you)熱脹冷縮(suo)(suo)等(deng)原因而產(chan)生的尺(chi)寸變(bian)(bian)化，或補(bu)(bu)償管(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)、容器(qi)(qi)等(deng)的軸向、橫向和角向位移。也可(ke)用(yong)(yong)于降噪減振。在(zai)現(xian)代工(gong)業(ye)中用(yong)(yong)途廣泛。供熱上，為了防止供熱管(guan)(guan)(guan)道升溫時，由(you)(you)于熱伸長(chang)或溫度應力而引起管(guan)(guan)(guan)道變(bian)(bian)形(xing)或破壞，需要(yao)在(zai)管(guan)(guan)(guan)道上設(she)置補(bu)(bu)償器(qi)(qi)，以(yi)補(bu)(bu)償管(guan)(guan)(guan)道的熱伸長(chang)，從而減小(xiao)管(guan)(guan)(guan)壁的應力和作(zuo)用(yong)(yong)在(zai)閥件(jian)或支(zhi)架(jia)結構(gou)上的作(zuo)用(yong)(yong)力。