補償器(qi)(qi)習慣上也叫膨脹(zhang)節，或伸縮(suo)節。由(you)構成其工作(zuo)主(zhu)體的(de)(de)波(bo)紋管(guan)(guan)(guan)(guan)（一種彈性元(yuan)件(jian)）和端(duan)管(guan)(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)(guan)等(deng)附件(jian)組成。 屬于(yu)(yu)一種補償元(yuan)件(jian)。利用(yong)(yong)其工作(zuo)主(zhu)體波(bo)紋管(guan)(guan)(guan)(guan)的(de)(de)有效伸縮(suo)變(bian)形，以(yi)吸收管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)由(you)熱(re)脹(zhang)冷(leng)縮(suo)等(deng)原因(yin)而(er)產生的(de)(de)尺(chi)寸變(bian)化(hua)，或補償管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)(qi)等(deng)的(de)(de)軸向、橫向和角向位移。也可用(yong)(yong)于(yu)(yu)降噪減(jian)振。在現(xian)代工業中用(yong)(yong)途(tu)廣泛(fan)。供(gong)熱(re)上，為了(le)防止供(gong)熱(re)管(guan)(guan)(guan)(guan)道升溫(wen)時，由(you)于(yu)(yu)熱(re)伸長或溫(wen)度應力而(er)引起管(guan)(guan)(guan)(guan)道變(bian)形或破壞，需要在管(guan)(guan)(guan)(guan)道上設置補償器(qi)(qi)，以(yi)補償管(guan)(guan)(guan)(guan)道的(de)(de)熱(re)伸長，從而(er)減(jian)小管(guan)(guan)(guan)(guan)壁的(de)(de)應力和作(zuo)用(yong)(yong)在閥件(jian)或支架結(jie)構上的(de)(de)作(zuo)用(yong)(yong)力。