補(bu)(bu)償(chang)器習慣上也(ye)叫(jiao)膨脹節，或(huo)伸縮節。由(you)構成其(qi)工作(zuo)主體(ti)的(de)(de)波紋(wen)管(guan)(guan)(guan)(guan)(guan)（一種彈性元件(jian)）和(he)端管(guan)(guan)(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)(guan)(guan)等(deng)附件(jian)組成。 屬于(yu)一種補(bu)(bu)償(chang)元件(jian)。利用(yong)(yong)其(qi)工作(zuo)主體(ti)波紋(wen)管(guan)(guan)(guan)(guan)(guan)的(de)(de)有效伸縮變(bian)形，以吸收(shou)管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容器等(deng)由(you)熱脹冷縮等(deng)原因而產生的(de)(de)尺寸變(bian)化(hua)，或(huo)補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容器等(deng)的(de)(de)軸(zhou)向、橫向和(he)角(jiao)向位移。也(ye)可用(yong)(yong)于(yu)降(jiang)噪減(jian)振(zhen)。在現代工業中用(yong)(yong)途(tu)廣泛。供(gong)熱上，為了防止供(gong)熱管(guan)(guan)(guan)(guan)(guan)道升溫時，由(you)于(yu)熱伸長或(huo)溫度(du)應力而引起管(guan)(guan)(guan)(guan)(guan)道變(bian)形或(huo)破壞，需要在管(guan)(guan)(guan)(guan)(guan)道上設置補(bu)(bu)償(chang)器，以補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)道的(de)(de)熱伸長，從(cong)而減(jian)小管(guan)(guan)(guan)(guan)(guan)壁的(de)(de)應力和(he)作(zuo)用(yong)(yong)在閥件(jian)或(huo)支架結(jie)構上的(de)(de)作(zuo)用(yong)(yong)力。