波紋管膨脹節是用金屬波紋管制成的一種膨脹節。它能沿管道軸線方向伸縮，也允許少(shao)量彎曲。圖2為(wei)常見的(de)軸向式(shi)(shi)波紋(wen)(wen)管(guan)(guan)(guan)(guan)膨脹(zhang)(zhang)(zhang)節(jie)，用(yong)(yong)在管(guan)(guan)(guan)(guan)道上進行軸向長(chang)度補償(chang)。為(wei)了(le)防止(zhi)超過允許的(de)補償(chang)量，在波紋(wen)(wen)管(guan)(guan)(guan)(guan)兩端設置(zhi)有保(bao)護拉桿或(huo)保(bao)護環，在與它連接的(de)兩端管(guan)(guan)(guan)(guan)道上設置(zhi)導向支架。另外還有轉角式(shi)(shi)和(he)橫(heng)向式(shi)(shi)膨脹(zhang)(zhang)(zhang)節(jie)，可(ke)用(yong)(yong)來補償(chang)管(guan)(guan)(guan)(guan)道的(de)轉角變(bian)形和(he)橫(heng)向變(bian)形。這(zhe)類(lei)(lei)膨脹(zhang)(zhang)(zhang)節(jie)的(de)優點(dian)是(shi)節(jie)省空(kong)間(jian)，節(jie)約材料，便(bian)于(yu)標(biao)準化和(he)批量生產，缺點(dian)是(shi)壽命較短。波紋(wen)(wen)管(guan)(guan)(guan)(guan)膨脹(zhang)(zhang)(zhang)節(jie)一般用(yong)(yong)于(yu)溫度和(he)壓力不很高、長(chang)度較短的(de)管(guan)(guan)(guan)(guan)道上。隨著波紋(wen)(wen)管(guan)(guan)(guan)(guan)生產技術水平(ping)的(de)提(ti)高，這(zhe)類(lei)(lei)膨脹(zhang)(zhang)(zhang)節(jie)的(de)應用(yong)(yong)范圍正在擴大。目前(qian)，波紋(wen)(wen)管(guan)(guan)(guan)(guan)膨脹(zhang)(zhang)(zhang)節(jie)可(ke)用(yong)(yong)在最高壓力6.0兆(zhao)帕的(de)管(guan)(guan)(guan)(guan)系中。