Spiral Prestressed Pipe Machine BPT-300

The BPT-300 spirally winds flat galvanized strip into finished corrugated duct at speeds up to 13.5 m/min. Variable speed control lets operators slow production for larger diameters or thicker material, ensuring consistent seam quality across the full 50–135 mm diameter range.

Each spiral turn is mechanically interlocked during forming, producing a duct that withstands the internal pressures of post-tension grouting — whether standard pressure grouting or vacuum-assisted grouting — without relying on welding or adhesives along its length.

The forming geometry is engineered so that a 36 mm strip covers 28 mm of effective duct wall per revolution. This controlled overlap ratio keeps raw material consumption predictable and cost-effective while delivering the flexibility required for curved tendon profiles in post-tensioned structures.

At 860 kg and under 1.5 m in any dimension, the machine can be transported to bridge decks, tunnel sites, or precast yards. An 11 kW motor runs on commonly available industrial power, eliminating the need for oversized generators or special electrical infrastructure.

Changeable roller dies and adjustable tooling accommodate two standard strip widths (36 mm and 48 mm) and pipe diameters from 50 mm to 135 mm. Switching between sizes is straightforward, reducing downtime when a project calls for multiple duct specifications.