Technical Shipment of ASTM B338 Gr.2 Titanium U Bend Tubes

ASTM B338 Gr.2 Titanium U Bend Tubes – Focus on Process Control & Inspection Integrity

We have successfully completed the production and shipment of a batch of ASTM B338 Grade 2 Titanium U-Bend Tubes (UNS R50400), specifically engineered for critical heat exchanger and condenser applications, which is shipped to Malaysia.

This project emphasizes strict process control, forming integrity, and non-destructive examination (NDE) to ensure long-term reliability under corrosive and thermal cycling conditions.

Raw Material Control & Traceability

All Titanium Grade 2 tubes are produced from certified billets with full traceability:

· Vacuum melting process (VAR) to ensure material purity

· 100% PMI (Positive Material Identification) before production

· Chemical composition verification per ASTM B338

· Inclusion control and grain structure inspection

Each tube is assigned a unique heat number to guarantee full traceability throughout the manufacturing cycle.

U Bend Forming – Critical Process Control

The U-bending process is tightly controlled as it directly impacts mechanical integrity and service life:

· Cold bending with internal mandrel support to prevent collapse

· Real-time monitoring of ovality and wall thinning ratio

· Bending radius strictly controlled according to TEMA requirements

· Surface protection to avoid galling and contamination

Key Technical Controls:

· Wall thinning ≤ specified tolerance (typically ≤10%)

· Ovality maintained within critical limits

· No micro-cracks in extrados/intrados zones

Post-bending, tubes may undergo stress relief annealing to eliminate residual stresses induced during deformation.

Heat Treatment & Metallurgical Stability

· Annealing in controlled atmosphere furnaces

· Temperature uniformity and holding time strictly monitored

· Prevention of oxidation and alpha-case formation

· Microstructure verification to ensure ductility and corrosion resistance

Non-Destructive Testing (NDT) & Inspection System

To ensure defect-free delivery, a comprehensive NDT regime is applied:

100% Inspection Coverage:

· Eddy Current Testing (ECT) – detection of surface/subsurface defects

· Hydrostatic Testing – pressure integrity verification

· Ultrasonic Testing (UT) – internal discontinuities (if required)

Critical Area Examination:

· Dye Penetrant Testing (PT) on U-bend zones

· Visual inspection for surface discontinuities and deformation

Dimensional Inspection:

· Leg length, center-to-center distance

· Ovality and wall thickness measurement in bend area

· Straightness and end squareness

Surface Quality & Cleanliness Control

· Pickling and passivation to remove oxide scale

· cleanliness control for heat exchanger service

· No embedded iron contamination (critical for titanium)

Process Documentation & Compliance

All Titanium U Tubes are delivered with complete documentation:

· EN 10204 3.1 Material Test Certificate (MTC)

· NDT reports (ECT / UT / PT / Hydrotest)

· Heat treatment records

· Dimensional inspection reports

Manufacturing and inspection procedures comply with:

· ASTM B338 / ASME SB338

· Client-specific technical specifications

Engineering Advantages of Process-Controlled Titanium U Tubes

Through strict control of forming and inspection processes, these Gr.2 Titanium U-Bend Tubes achieve:

· Superior resistance to seawater corrosion and chloride attack

· High structural integrity in U-bend critical zones

· Excellent fatigue resistance under thermal cycling

· Extended operational lifespan in heat exchanger systems