補(bu)償(chang)器(qi)(qi)習慣上(shang)也叫膨脹(zhang)節，或(huo)伸縮節。由構成(cheng)其(qi)工(gong)作(zuo)主(zhu)體的(de)波紋管(guan)(guan)(guan)(guan)(guan)（一(yi)種彈(dan)性(xing)元件(jian)）和(he)(he)端管(guan)(guan)(guan)(guan)(guan)、支架、法(fa)蘭、導管(guan)(guan)(guan)(guan)(guan)等附件(jian)組成(cheng)。 屬于一(yi)種補(bu)償(chang)元件(jian)。利用(yong)其(qi)工(gong)作(zuo)主(zhu)體波紋管(guan)(guan)(guan)(guan)(guan)的(de)有效伸縮變(bian)(bian)形(xing)，以吸收管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容器(qi)(qi)等由熱(re)脹(zhang)冷縮等原因而產生的(de)尺寸變(bian)(bian)化，或(huo)補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)、容器(qi)(qi)等的(de)軸向(xiang)、橫向(xiang)和(he)(he)角(jiao)向(xiang)位移。也可用(yong)于降(jiang)噪減振。在(zai)現代工(gong)業中(zhong)用(yong)途(tu)廣泛(fan)。供熱(re)上(shang)，為(wei)了(le)防(fang)止供熱(re)管(guan)(guan)(guan)(guan)(guan)道(dao)升(sheng)溫(wen)(wen)時(shi)，由于熱(re)伸長(chang)或(huo)溫(wen)(wen)度(du)應力而引(yin)起管(guan)(guan)(guan)(guan)(guan)道(dao)變(bian)(bian)形(xing)或(huo)破壞，需要在(zai)管(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)設置補(bu)償(chang)器(qi)(qi)，以補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)道(dao)的(de)熱(re)伸長(chang)，從而減小(xiao)管(guan)(guan)(guan)(guan)(guan)壁的(de)應力和(he)(he)作(zuo)用(yong)在(zai)閥件(jian)或(huo)支架結構上(shang)的(de)作(zuo)用(yong)力。