補(bu)(bu)償器(qi)習(xi)慣上也叫膨脹節，或伸縮節。由構成其工(gong)作主體的(de)波紋管(guan)(guan)(guan)（一(yi)種(zhong)彈性元件(jian)(jian)）和端管(guan)(guan)(guan)、支架、法(fa)蘭、導管(guan)(guan)(guan)等(deng)附(fu)件(jian)(jian)組成。 屬于一(yi)種(zhong)補(bu)(bu)償元件(jian)(jian)。利用(yong)其工(gong)作主體波紋管(guan)(guan)(guan)的(de)有效伸縮變(bian)形，以(yi)吸收管(guan)(guan)(guan)線、導管(guan)(guan)(guan)、容器(qi)等(deng)由熱脹冷縮等(deng)原因而產生的(de)尺(chi)寸變(bian)化，或補(bu)(bu)償管(guan)(guan)(guan)線、導管(guan)(guan)(guan)、容器(qi)等(deng)的(de)軸向(xiang)、橫向(xiang)和角向(xiang)位移(yi)。也可用(yong)于降噪減振。在現代工(gong)業(ye)中用(yong)途廣泛。供(gong)熱上，為了防止供(gong)熱管(guan)(guan)(guan)道升溫時，由于熱伸長(chang)或溫度應力(li)而引起(qi)管(guan)(guan)(guan)道變(bian)形或破(po)壞，需(xu)要在管(guan)(guan)(guan)道上設置補(bu)(bu)償器(qi)，以(yi)補(bu)(bu)償管(guan)(guan)(guan)道的(de)熱伸長(chang)，從而減小管(guan)(guan)(guan)壁的(de)應力(li)和作用(yong)在閥件(jian)(jian)或支架結構上的(de)作用(yong)力(li)。