膨脹(zhang)(zhang)節習慣(guan)上(shang)(shang)(shang)也(ye)叫補(bu)(bu)償(chang)器，或(huo)伸(shen)縮節。由構成其工作(zuo)主體(ti)的(de)(de)波紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)(一種彈性(xing)元件(jian))和端管(guan)(guan)(guan)(guan)(guan)(guan)、支架、法(fa)蘭、導管(guan)(guan)(guan)(guan)(guan)(guan)等(deng)附件(jian)組成。 膨脹(zhang)(zhang)節是(shi)為了補(bu)(bu)償(chang)因溫度差與機械振動(dong)引起的(de)(de)附加(jia)應(ying)力(li)，而設(she)置在(zai)容(rong)器殼體(ti)或(huo)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)(shang)的(de)(de)一種撓性(xing)結(jie)構。利(li)用(yong)(yong)其工作(zuo)主體(ti)波紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)有效伸(shen)縮變形(xing)，以吸(xi)收(shou)管(guan)(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)器等(deng)由熱脹(zhang)(zhang)冷縮等(deng)原(yuan)因而產生的(de)(de)尺寸變化，或(huo)補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)器等(deng)的(de)(de)軸(zhou)向、橫(heng)向和角向位(wei)移。也(ye)可用(yong)(yong)于降噪減振。供熱上(shang)(shang)(shang)，為了防止供熱管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)升溫時，由于熱伸(shen)長或(huo)溫度應(ying)力(li)而引起管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)變形(xing)或(huo)破壞，需(xu)要在(zai)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)上(shang)(shang)(shang)設(she)置補(bu)(bu)償(chang)器，以補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)的(de)(de)熱伸(shen)長，從而減小管(guan)(guan)(guan)(guan)(guan)(guan)壁的(de)(de)應(ying)力(li)和作(zuo)用(yong)(yong)在(zai)閥件(jian)或(huo)支架結(jie)構上(shang)(shang)(shang)的(de)(de)作(zuo)用(yong)(yong)力(li)。