Grade 2 vs Grade 5 vs Grade 7 vs Grade 12 Titanium Pipe Fittings
Grade 2, Grade 5, Grade 7 and Grade 12 titanium fittings are selected for different combinations of corrosion resistance, strength and fabrication—not by assuming that a higher grade number is better. Match the fitting to the connected pipe, service chemistry, temperature, pressure design, welding procedure and governing code.
Titanium Fitting Grade Comparison
| Grade | UNS / alloy family | Primary selection emphasis | Critical review |
|---|---|---|---|
| Grade 2 | R50400, commercially pure titanium | General corrosion resistance, formability and weldability | Service chemistry, strength, crevices and connected pipe |
| Grade 5 | R56400, Ti-6Al-4V | Higher strength and strength-to-weight performance | Corrosion compatibility, product route, welding and code acceptance |
| Grade 7 | R52400, palladium-alloyed commercially pure titanium | Selected reducing or crevice-corrosion conditions | Complete chemical environment and economic justification |
| Grade 12 | R53400, Ti-Ni-Mo alloy | Selected corrosion and elevated-temperature strength requirements | Specification, availability, forming and welding procedure |
Use current product specifications and certified values for exact chemistry and mechanical acceptance. This matrix supports initial selection only.
Separate Strength Selection From Corrosion Selection
Grade 5 is commonly considered when higher strength is required, but higher strength does not prove better corrosion performance in a given process. Grade 7 and Grade 12 may be chosen for specific corrosion conditions, but neither is a universal upgrade. Review fluid composition, concentration, temperature, aeration, contaminants, velocity, deposits, crevices, cleaning and upset conditions.
Match the Connected Pipe and Welding Procedure
Confirm whether fitting and pipe grades are the same or part of an engineered dissimilar-grade joint. Define filler-metal policy, WPS/PQR, heat treatment, cleanliness and shielding. A substitution that appears acceptable by chemistry may change strength, corrosion behavior, weld qualification and code compliance.
Product Form and Manufacturing Route
The requested grade must be available in the required fitting type, wall, size and construction. State seamless or welded route where required, applicable product and dimensional standards, and whether the component is standard or drawing-specific. Do not copy allowable dimensions or properties from plate, bar or pipe when the fitting specification controls acceptance.
Product Options
Grade 2 Titanium Fittings, Grade 5 Titanium Fittings, Grade 7 Titanium Fittings, Grade 12 Titanium Fittings and the Titanium Fittings family.
Send the Service Before Fixing the Grade
Provide the medium, all operating temperatures, pressure, connected pipe, fitting type, dimensions, welding code and inspection requirements for review.
RFQ Checklist
- Service medium, concentration, temperature and upset conditions
- Grade, product standard, dimensional standard and revision
- Fitting type, NPS/OD, wall, ends and quantity
- Connected pipe, welding and heat-treatment requirements
- Inspection, certificate and traceability
FAQ
Is Grade 7 always more corrosion resistant than Grade 2?
No. Grade 7 offers advantages in selected environments; suitability depends on the actual service.
Can Grade 5 fittings be welded to Grade 2 pipe?
Only after engineering and welding-procedure review. Strength, corrosion, filler metal and code requirements must be addressed.
Can grades be distinguished visually?
No. Use marking, traceability, material certificates and required verification testing.
Related Reading
Butt Weld Fittings Matrix · Seawater and Desalination Components · Grade 2 vs Grade 7 Tube