補(bu)(bu)償器習慣上(shang)也叫膨脹節，或(huo)(huo)伸縮(suo)節。由構成其工作主體的(de)波紋管(guan)(guan)(guan)(guan)（一種彈性元件(jian)）和端管(guan)(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)(guan)等(deng)附件(jian)組成。 屬于一種補(bu)(bu)償元件(jian)。利用(yong)(yong)其工作主體波紋管(guan)(guan)(guan)(guan)的(de)有效伸縮(suo)變形，以吸收管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器等(deng)由熱(re)(re)脹冷(leng)縮(suo)等(deng)原因(yin)而產生的(de)尺寸變化，或(huo)(huo)補(bu)(bu)償管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器等(deng)的(de)軸向、橫向和角(jiao)向位移(yi)。也可用(yong)(yong)于降(jiang)噪減(jian)振(zhen)。在(zai)現(xian)代(dai)工業中用(yong)(yong)途廣(guang)泛。供熱(re)(re)上(shang)，為(wei)了(le)防(fang)止(zhi)供熱(re)(re)管(guan)(guan)(guan)(guan)道升溫(wen)時，由于熱(re)(re)伸長或(huo)(huo)溫(wen)度應力(li)而引起管(guan)(guan)(guan)(guan)道變形或(huo)(huo)破壞(huai)，需(xu)要在(zai)管(guan)(guan)(guan)(guan)道上(shang)設置補(bu)(bu)償器，以補(bu)(bu)償管(guan)(guan)(guan)(guan)道的(de)熱(re)(re)伸長，從而減(jian)小(xiao)管(guan)(guan)(guan)(guan)壁的(de)應力(li)和作用(yong)(yong)在(zai)閥件(jian)或(huo)(huo)支架結構上(shang)的(de)作用(yong)(yong)力(li)。