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(yu)(yu)一(yi)種補(bu)償元件(jian)(jian)。利用(yong)(yong)其工作主體波紋管(guan)(guan)(guan)(guan)的(de)(de)有效(xiao)伸縮變形(xing)，以(yi)吸(xi)收管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)由(you)熱脹冷(leng)縮等(deng)原因而產(chan)生的(de)(de)尺寸變化，或(huo)補(bu)償管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)的(de)(de)軸向、橫向和角向位移。也可用(yong)(yong)于(yu)(yu)降(jiang)噪(zao)減振。在(zai)現(xian)代工業中用(yong)(yong)途廣泛。供(gong)(gong)熱上(shang)，為了防止供(gong)(gong)熱管(guan)(guan)(guan)(guan)道升溫(wen)時(shi)，由(you)于(yu)(yu)熱伸長(chang)(chang)或(huo)溫(wen)度應(ying)力而引起管(guan)(guan)(guan)(guan)道變形(xing)或(huo)破壞，需(xu)要(yao)在(zai)管(guan)(guan)(guan)(guan)道上(shang)設置(zhi)補(bu)償器(qi)，以(yi)補(bu)償管(guan)(guan)(guan)(guan)道的(de)(de)熱伸長(chang)(chang)，從而減小管(guan)(guan)(guan)(guan)壁的(de)(de)應(ying)力和作用(yong)(yong)在(zai)閥件(jian)(jian)或(huo)支架結(jie)構(gou)上(shang)的(de)(de)作用(yong)(yong)力。