膨(peng)脹(zhang)(zhang)(zhang)節(jie)(jie)習(xi)慣上(shang)也叫補(bu)償(chang)器(qi)，或(huo)伸(shen)(shen)縮節(jie)(jie)。由(you)(you)構(gou)成(cheng)其(qi)工(gong)作主體的波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)(一(yi)種彈(dan)性(xing)元(yuan)件(jian))和端(duan)管(guan)(guan)(guan)(guan)(guan)、支(zhi)架(jia)(jia)、法(fa)蘭、導管(guan)(guan)(guan)(guan)(guan)等附件(jian)組成(cheng)。 膨(peng)脹(zhang)(zhang)(zhang)節(jie)(jie)是為了補(bu)償(chang)因溫(wen)(wen)度差與機(ji)械振動(dong)引(yin)起的附加應力(li)，而設(she)置在容(rong)器(qi)殼體或(huo)管(guan)(guan)(guan)(guan)(guan)道上(shang)的一(yi)種撓性(xing)結構(gou)。利用其(qi)工(gong)作主體波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)的有效伸(shen)(shen)縮變形，以吸(xi)收管(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)等由(you)(you)熱(re)(re)脹(zhang)(zhang)(zhang)冷縮等原(yuan)因而產生的尺寸變化，或(huo)補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)等的軸向(xiang)、橫(heng)向(xiang)和角(jiao)向(xiang)位移。也可用于(yu)降(jiang)噪減(jian)振。供(gong)熱(re)(re)上(shang)，為了防止供(gong)熱(re)(re)管(guan)(guan)(guan)(guan)(guan)道升溫(wen)(wen)時，由(you)(you)于(yu)熱(re)(re)伸(shen)(shen)長(chang)或(huo)溫(wen)(wen)度應力(li)而引(yin)起管(guan)(guan)(guan)(guan)(guan)道變形或(huo)破壞，需要在管(guan)(guan)(guan)(guan)(guan)道上(shang)設(she)置補(bu)償(chang)器(qi)，以補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)道的熱(re)(re)伸(shen)(shen)長(chang)，從而減(jian)小管(guan)(guan)(guan)(guan)(guan)壁的應力(li)和作用在閥件(jian)或(huo)支(zhi)架(jia)(jia)結構(gou)上(shang)的作用力(li)。