補(bu)償(chang)(chang)器習慣上(shang)(shang)也叫膨脹節，或伸縮節。由構成(cheng)(cheng)其(qi)工作(zuo)主體(ti)(ti)的波(bo)紋管(guan)(guan)(guan)(guan)(guan)（一種彈性(xing)元件）和端管(guan)(guan)(guan)(guan)(guan)、支(zhi)架、法(fa)蘭、導(dao)管(guan)(guan)(guan)(guan)(guan)等(deng)(deng)(deng)附件組(zu)成(cheng)(cheng)。 屬于(yu)(yu)一種補(bu)償(chang)(chang)元件。利用(yong)(yong)其(qi)工作(zuo)主體(ti)(ti)波(bo)紋管(guan)(guan)(guan)(guan)(guan)的有效伸縮變(bian)形，以吸(xi)收管(guan)(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)(guan)、容器等(deng)(deng)(deng)由熱(re)脹冷縮等(deng)(deng)(deng)原因而(er)產生的尺(chi)寸(cun)變(bian)化(hua)，或補(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)(guan)、容器等(deng)(deng)(deng)的軸(zhou)向、橫(heng)向和角(jiao)向位移(yi)。也可用(yong)(yong)于(yu)(yu)降噪(zao)減(jian)振。在現代(dai)工業中用(yong)(yong)途廣泛(fan)。供熱(re)上(shang)(shang)，為了(le)防止(zhi)供熱(re)管(guan)(guan)(guan)(guan)(guan)道升溫(wen)時，由于(yu)(yu)熱(re)伸長或溫(wen)度(du)應力而(er)引起管(guan)(guan)(guan)(guan)(guan)道變(bian)形或破壞(huai)，需要在管(guan)(guan)(guan)(guan)(guan)道上(shang)(shang)設置補(bu)償(chang)(chang)器，以補(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)道的熱(re)伸長，從而(er)減(jian)小管(guan)(guan)(guan)(guan)(guan)壁的應力和作(zuo)用(yong)(yong)在閥件或支(zhi)架結構上(shang)(shang)的作(zuo)用(yong)(yong)力。