補償(chang)器習慣上也(ye)叫膨脹節，或伸(shen)縮節。由構成(cheng)其工(gong)(gong)作(zuo)主(zhu)體的(de)波(bo)紋管(guan)(guan)(guan)(guan)(guan)（一(yi)種(zhong)(zhong)彈性元件）和端(duan)管(guan)(guan)(guan)(guan)(guan)、支架、法蘭、導(dao)管(guan)(guan)(guan)(guan)(guan)等附件組成(cheng)。 屬于(yu)一(yi)種(zhong)(zhong)補償(chang)元件。利(li)用(yong)其工(gong)(gong)作(zuo)主(zhu)體波(bo)紋管(guan)(guan)(guan)(guan)(guan)的(de)有效(xiao)伸(shen)縮變形，以吸收(shou)管(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)、容器等由熱(re)(re)脹冷縮等原因而(er)產生的(de)尺寸(cun)變化，或補償(chang)管(guan)(guan)(guan)(guan)(guan)線、導(dao)管(guan)(guan)(guan)(guan)(guan)、容器等的(de)軸向(xiang)、橫向(xiang)和角向(xiang)位(wei)移。也(ye)可用(yong)于(yu)降噪(zao)減(jian)振。在現代(dai)工(gong)(gong)業中用(yong)途廣泛。供熱(re)(re)上，為(wei)了防(fang)止供熱(re)(re)管(guan)(guan)(guan)(guan)(guan)道升溫時，由于(yu)熱(re)(re)伸(shen)長或溫度應力(li)而(er)引起管(guan)(guan)(guan)(guan)(guan)道變形或破壞，需(xu)要在管(guan)(guan)(guan)(guan)(guan)道上設置(zhi)補償(chang)器，以補償(chang)管(guan)(guan)(guan)(guan)(guan)道的(de)熱(re)(re)伸(shen)長，從(cong)而(er)減(jian)小管(guan)(guan)(guan)(guan)(guan)壁的(de)應力(li)和作(zuo)用(yong)在閥(fa)件或支架結構上的(de)作(zuo)用(yong)力(li)。