補償器習慣上(shang)也叫膨脹節，或(huo)伸(shen)縮節。由構成其(qi)工(gong)作(zuo)主(zhu)體的(de)波紋管(guan)(guan)(guan)(guan)（一種彈性元(yuan)件(jian)）和(he)端管(guan)(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)(guan)等附件(jian)組成。 屬(shu)于(yu)一種補償元(yuan)件(jian)。利用(yong)其(qi)工(gong)作(zuo)主(zhu)體波紋管(guan)(guan)(guan)(guan)的(de)有效(xiao)伸(shen)縮變形(xing)，以吸收管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器等由熱(re)脹冷縮等原因而產生的(de)尺寸變化，或(huo)補償管(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)、容器等的(de)軸向(xiang)、橫向(xiang)和(he)角(jiao)向(xiang)位移。也可用(yong)于(yu)降噪減振。在現(xian)代工(gong)業中用(yong)途廣泛(fan)。供(gong)熱(re)上(shang)，為了防止(zhi)供(gong)熱(re)管(guan)(guan)(guan)(guan)道(dao)升溫(wen)時，由于(yu)熱(re)伸(shen)長(chang)或(huo)溫(wen)度應(ying)(ying)力(li)(li)而引起管(guan)(guan)(guan)(guan)道(dao)變形(xing)或(huo)破壞，需要在管(guan)(guan)(guan)(guan)道(dao)上(shang)設置補償器，以補償管(guan)(guan)(guan)(guan)道(dao)的(de)熱(re)伸(shen)長(chang)，從而減小管(guan)(guan)(guan)(guan)壁的(de)應(ying)(ying)力(li)(li)和(he)作(zuo)用(yong)在閥件(jian)或(huo)支架結構上(shang)的(de)作(zuo)用(yong)力(li)(li)。