補(bu)償(chang)器(qi)(qi)習(xi)慣上也(ye)叫膨脹節，或伸縮節。由(you)構成其工作主(zhu)體的(de)(de)波紋管(guan)(guan)(guan)(guan)（一種彈性(xing)元件(jian)(jian)(jian)(jian)）和端管(guan)(guan)(guan)(guan)、支架、法(fa)蘭、導(dao)(dao)管(guan)(guan)(guan)(guan)等(deng)附件(jian)(jian)(jian)(jian)組成。 屬于一種補(bu)償(chang)元件(jian)(jian)(jian)(jian)。利用其工作主(zhu)體波紋管(guan)(guan)(guan)(guan)的(de)(de)有效伸縮變(bian)形，以(yi)吸收管(guan)(guan)(guan)(guan)線(xian)、導(dao)(dao)管(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)由(you)熱脹冷縮等(deng)原因而產生的(de)(de)尺(chi)寸(cun)變(bian)化，或補(bu)償(chang)管(guan)(guan)(guan)(guan)線(xian)、導(dao)(dao)管(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)的(de)(de)軸向、橫向和角向位移。也(ye)可(ke)用于降(jiang)噪減振。在(zai)現(xian)代工業中(zhong)用途廣泛(fan)。供熱上，為了防止供熱管(guan)(guan)(guan)(guan)道(dao)(dao)升溫(wen)時，由(you)于熱伸長或溫(wen)度應(ying)(ying)力而引起管(guan)(guan)(guan)(guan)道(dao)(dao)變(bian)形或破壞，需要(yao)在(zai)管(guan)(guan)(guan)(guan)道(dao)(dao)上設置補(bu)償(chang)器(qi)(qi)，以(yi)補(bu)償(chang)管(guan)(guan)(guan)(guan)道(dao)(dao)的(de)(de)熱伸長，從而減小(xiao)管(guan)(guan)(guan)(guan)壁(bi)的(de)(de)應(ying)(ying)力和作用在(zai)閥件(jian)(jian)(jian)(jian)或支架結構上的(de)(de)作用力。