補(bu)(bu)償(chang)器(qi)習慣上也叫膨脹節(jie)(jie)，或(huo)(huo)伸縮(suo)節(jie)(jie)。由(you)構(gou)成其(qi)工(gong)作主體的(de)波(bo)紋管(guan)(guan)(guan)(guan)(guan)（一(yi)種彈性元(yuan)件(jian)(jian)）和(he)端管(guan)(guan)(guan)(guan)(guan)、支架(jia)、法蘭、導管(guan)(guan)(guan)(guan)(guan)等(deng)附件(jian)(jian)組成。 屬于一(yi)種補(bu)(bu)償(chang)元(yuan)件(jian)(jian)。利用(yong)其(qi)工(gong)作主體波(bo)紋管(guan)(guan)(guan)(guan)(guan)的(de)有效伸縮(suo)變形(xing)，以吸收管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容器(qi)等(deng)由(you)熱(re)脹冷(leng)縮(suo)等(deng)原因而產生的(de)尺寸變化，或(huo)(huo)補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容器(qi)等(deng)的(de)軸向、橫向和(he)角向位移。也可(ke)用(yong)于降噪減振。在(zai)現代工(gong)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(wen)時，由(you)于熱(re)伸長或(huo)(huo)溫(wen)度應力(li)(li)而引起管(guan)(guan)(guan)(guan)(guan)道變形(xing)或(huo)(huo)破壞，需要在(zai)管(guan)(guan)(guan)(guan)(guan)道上設置(zhi)補(bu)(bu)償(chang)器(qi)，以補(bu)(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(li)(li)和(he)作用(yong)在(zai)閥件(jian)(jian)或(huo)(huo)支架(jia)結(jie)構(gou)上的(de)作用(yong)力(li)(li)。