目前国内外对波纹膨胀节的制造,采用滚压成形和液压成形二大类。用液压成形时,在成形过程中,除了管坯内部需要有胀形的压力外,还要在波纹膨胀节管坯的轴向上,施加推进力。对于大型的波纹膨胀节和多层的波纹膨胀节,此轴向推力数值很大,这就需要大吨位的压机。目前国内只有少数化工机械厂,可以制造大型波纹膨胀节,主要是压机吨位不够。 At present, the manufacture of corrugated expansion joints at home and abroad adopts two major categories of roll forming and hydroforming. With hydroforming, in the forming process, in addition to the inner tube requires bulging pressure, but also in the corrugated expansion joint tube in the axial direction, to impose propulsion. For large corrugated expansion joints and multi-layer corrugated expansion joints, this axial thrust is large and requires a large tonnage press. At present, there are only a few chemical machinery factories in China that can manufacture large-scale corrugated expansion joints mainly because the tonnage of presses is not enough.