補(bu)償(chang)器(qi)(qi)習慣(guan)上也叫膨(peng)脹節，或(huo)伸縮節。由構成(cheng)其工作主體的(de)波紋管(guan)(guan)(guan)(guan)(guan)（一(yi)種彈性元件(jian)(jian)）和(he)端(duan)管(guan)(guan)(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)(guan)(guan)等(deng)附件(jian)(jian)組成(cheng)。 屬于(yu)(yu)一(yi)種補(bu)償(chang)元件(jian)(jian)。利用(yong)其工作主體波紋管(guan)(guan)(guan)(guan)(guan)的(de)有效伸縮變形(xing)，以(yi)吸收管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)由熱(re)脹冷縮等(deng)原因而產生的(de)尺寸變化，或(huo)補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)的(de)軸向(xiang)、橫向(xiang)和(he)角向(xiang)位移。也可用(yong)于(yu)(yu)降(jiang)噪減振(zhen)。在現代工業中用(yong)途廣泛。供熱(re)上，為了防止供熱(re)管(guan)(guan)(guan)(guan)(guan)道升溫時，由于(yu)(yu)熱(re)伸長或(huo)溫度應力而引起管(guan)(guan)(guan)(guan)(guan)道變形(xing)或(huo)破壞，需要在管(guan)(guan)(guan)(guan)(guan)道上設置(zhi)補(bu)償(chang)器(qi)(qi)，以(yi)補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)道的(de)熱(re)伸長，從而減小管(guan)(guan)(guan)(guan)(guan)壁的(de)應力和(he)作用(yong)在閥件(jian)(jian)或(huo)支架結(jie)構上的(de)作用(yong)力。