Chemical and Energy Technical Explainer By Jason/ On 06 Nov, 2026 ASTM B338 Titanium U-Tube Bending: Vacuum Stress Relief & Apex Wall Thinning Engineering guide to ASTM B338 Grade 2 titanium U-tubes for shell and tube heat exchangers: bend radius limits, apex wall thinning (≤12%), ovality (≤8%), and vacuum stress relief.