補償器(qi)習慣上(shang)也叫膨脹(zhang)節，或(huo)伸縮節。由(you)構(gou)(gou)成(cheng)(cheng)其(qi)工(gong)作主體(ti)的(de)(de)波紋管(guan)(guan)(guan)(guan)（一(yi)種彈性元件(jian)）和(he)(he)端管(guan)(guan)(guan)(guan)、支架(jia)(jia)、法蘭、導(dao)管(guan)(guan)(guan)(guan)等(deng)(deng)附件(jian)組成(cheng)(cheng)。 屬于(yu)一(yi)種補償元件(jian)。利用(yong)(yong)其(qi)工(gong)作主體(ti)波紋管(guan)(guan)(guan)(guan)的(de)(de)有效伸縮變形，以(yi)吸(xi)收管(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)(deng)由(you)熱脹(zhang)冷縮等(deng)(deng)原因而(er)產生的(de)(de)尺寸(cun)變化(hua)，或(huo)補償管(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)、容(rong)器(qi)等(deng)(deng)的(de)(de)軸(zhou)向、橫向和(he)(he)角向位移。也可用(yong)(yong)于(yu)降噪(zao)減振。在現代工(gong)業中用(yong)(yong)途廣泛。供熱上(shang)，為了防止供熱管(guan)(guan)(guan)(guan)道升溫時，由(you)于(yu)熱伸長(chang)或(huo)溫度應力而(er)引起管(guan)(guan)(guan)(guan)道變形或(huo)破(po)壞(huai)，需要(yao)在管(guan)(guan)(guan)(guan)道上(shang)設置補償器(qi)，以(yi)補償管(guan)(guan)(guan)(guan)道的(de)(de)熱伸長(chang)，從而(er)減小管(guan)(guan)(guan)(guan)壁的(de)(de)應力和(he)(he)作用(yong)(yong)在閥(fa)件(jian)或(huo)支架(jia)(jia)結構(gou)(gou)上(shang)的(de)(de)作用(yong)(yong)力。