Continuous Tube ((full)) -

This governs spooling diameter for transport.

Bending stress: $\sigma = E \epsilon = 200\times10^3 \times 0.01058 = 2116$ MPa → exceeds yield → occurs. The tube will permanently deform but not fracture if $\epsilon < \epsilon_fracture$ (≈5% for steel). Minimum elastic bend radius: $R_min,elastic = \fracE \cdot D2\sigma_y = \frac200000 \times 25.42 \times 350 = 7257$ mm (7.26 m). So coiling onto a 1.2 m reel causes plastic yielding – acceptable for coiled tubing applications. continuous tube

| Property | Continuous Tube | Discrete (Welded joint) Tube | |----------|----------------|-------------------------------| | Leak probability | Extremely low | Higher at welds/threads | | Pressure drop | Smooth bore, minimal | Small disturbances at joints | | Fatigue life | Unlimited (no welds) | Limited by weld HAZ | | Installation cost | Low (one pull) | High (many joint make-ups) | | Repair | Difficult (must replace section) | Easy (replace joint) | | Transport | Requires spool (heavy) | Sticks (easy to handle) | This governs spooling diameter for transport

The demand for continuous tubes is expected to grow in the coming years, driven by increasing infrastructure development, urbanization, and industrialization. Advances in materials science and manufacturing technologies are also expected to improve the performance and sustainability of continuous tubes. Minimum elastic bend radius: $R_min,elastic = \fracE \cdot

A "continuous tube" refers to a hollow cylindrical structure produced without transverse joints or seams along its length, effectively infinite in theoretical length or limited only by manufacturing and handling capabilities. Unlike discrete tubes cut to fixed lengths, continuous tubes are characterized by uniform cross-section, absence of end effects (until cut), and superior mechanical integrity due to the lack of circumferential welds. This report covers the fundamental characteristics, production technologies (seamless and welded), stress analysis, material considerations, and industrial applications.