補償器習慣上也叫膨脹節，或伸縮節。由構成其工作主體的波紋管（一種彈性元件）和端管、支架、法蘭、導管等附件組成。膨脹節廠家 屬于(yu)一種(zhong)補(bu)償(chang)(chang)元(yuan)件(jian)。利用(yong)(yong)其工作主(zhu)體波紋(wen)管(guan)(guan)(guan)的(de)有(you)效伸(shen)縮(suo)變(bian)(bian)(bian)形(xing)，以(yi)吸收(shou)管(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)、容(rong)器(qi)等由熱(re)脹(zhang)冷(leng)縮(suo)等原因(yin)而(er)產生的(de)尺(chi)寸變(bian)(bian)(bian)化，或補(bu)償(chang)(chang)管(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)、容(rong)器(qi)等的(de)軸向(xiang)、橫(heng)向(xiang)和角向(xiang)位移(yi)。也可用(yong)(yong)于(yu)降噪(zao)減振。在(zai)現(xian)代工業(ye)中(zhong)用(yong)(yong)途(tu)廣泛(fan)。供熱(re)上，為(wei)了防止供熱(re)管(guan)(guan)(guan)道(dao)(dao)升溫時，由于(yu)熱(re)伸(shen)長或溫度應力而(er)引起管(guan)(guan)(guan)道(dao)(dao)變(bian)(bian)(bian)形(xing)或破(po)壞，需要在(zai)管(guan)(guan)(guan)道(dao)(dao)上設(she)置補(bu)償(chang)(chang)器(qi)，以(yi)補(bu)償(chang)(chang)管(guan)(guan)(guan)道(dao)(dao)的(de)熱(re)伸(shen)長，從而(er)減小管(guan)(guan)(guan)壁的(de)應力和作用(yong)(yong)在(zai)閥(fa)件(jian)或支(zhi)架結構上的(de)作用(yong)(yong)力。