補(bu)(bu)償(chang)(chang)器習慣上也(ye)叫膨(peng)脹(zhang)節，或伸縮節。由(you)構成其(qi)工作主體的(de)(de)波紋管(guan)(guan)(guan)(guan)（一種彈(dan)性元件(jian)(jian)）和端管(guan)(guan)(guan)(guan)、支(zhi)架、法蘭、導管(guan)(guan)(guan)(guan)等附件(jian)(jian)組成。 屬于一種補(bu)(bu)償(chang)(chang)元件(jian)(jian)。利用(yong)(yong)其(qi)工作主體波紋管(guan)(guan)(guan)(guan)的(de)(de)有效伸縮變(bian)形(xing)，以吸收(shou)管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器等由(you)熱脹(zhang)冷縮等原因(yin)而(er)產生(sheng)的(de)(de)尺(chi)寸變(bian)化(hua)，或補(bu)(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器等的(de)(de)軸向(xiang)、橫向(xiang)和角向(xiang)位移。也(ye)可(ke)用(yong)(yong)于降噪減振。在現代工業中(zhong)用(yong)(yong)途廣泛。供熱上，為了防止供熱管(guan)(guan)(guan)(guan)道升溫(wen)時，由(you)于熱伸長(chang)或溫(wen)度應(ying)力而(er)引起管(guan)(guan)(guan)(guan)道變(bian)形(xing)或破(po)壞，需要在管(guan)(guan)(guan)(guan)道上設置補(bu)(bu)償(chang)(chang)器，以補(bu)(bu)償(chang)(chang)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(ying)力和作用(yong)(yong)在閥件(jian)(jian)或支(zhi)架結構上的(de)(de)作用(yong)(yong)力。