補(bu)(bu)償器(qi)習慣上(shang)(shang)(shang)也(ye)叫膨脹節，或(huo)伸縮節。由(you)構成(cheng)其(qi)工(gong)(gong)作(zuo)(zuo)主體(ti)(ti)的(de)(de)波(bo)紋管(guan)(guan)(guan)(guan)（一(yi)種彈性(xing)元件(jian)）和(he)(he)端管(guan)(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)(guan)等(deng)附(fu)件(jian)組成(cheng)。 屬于(yu)(yu)一(yi)種補(bu)(bu)償元件(jian)。利(li)用(yong)(yong)其(qi)工(gong)(gong)作(zuo)(zuo)主體(ti)(ti)波(bo)紋管(guan)(guan)(guan)(guan)的(de)(de)有(you)效(xiao)伸縮變(bian)(bian)形，以(yi)吸收管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)等(deng)由(you)熱脹冷(leng)縮等(deng)原(yuan)因而產生的(de)(de)尺(chi)寸變(bian)(bian)化，或(huo)補(bu)(bu)償管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)等(deng)的(de)(de)軸向、橫向和(he)(he)角向位移。也(ye)可用(yong)(yong)于(yu)(yu)降(jiang)噪減振。在(zai)現代工(gong)(gong)業中用(yong)(yong)途廣泛。供熱上(shang)(shang)(shang)，為了防止供熱管(guan)(guan)(guan)(guan)道(dao)升溫時，由(you)于(yu)(yu)熱伸長或(huo)溫度應(ying)(ying)力(li)(li)而引起(qi)管(guan)(guan)(guan)(guan)道(dao)變(bian)(bian)形或(huo)破(po)壞，需(xu)要在(zai)管(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)(shang)設置補(bu)(bu)償器(qi)，以(yi)補(bu)(bu)償管(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱伸長，從而減小管(guan)(guan)(guan)(guan)壁的(de)(de)應(ying)(ying)力(li)(li)和(he)(he)作(zuo)(zuo)用(yong)(yong)在(zai)閥件(jian)或(huo)支架結構上(shang)(shang)(shang)的(de)(de)作(zuo)(zuo)用(yong)(yong)力(li)(li)。