Where titanium gets specified
Titanium is not chosen because it is exotic. It is chosen in a narrow set of duties where the alternative costs more over the life of the plant: chloride-bearing water, wet chlorine, oxidising acids, and service temperatures where stainless steels lose their passive film. In those environments the material forms a stable oxide layer that resists crevice and pitting attack, and the component survives a campaign that would consume a cheaper alloy.
The four duties below are the ones we are asked about most often. Each has a page of its own covering the grades normally specified, the product forms involved and what to state in an enquiry.
Chemical processing
Reactors, columns, piping and linings in Grade 2 and Grade 7 for chlor-alkali, acid and fine-chemical duty.
Chemical service →
Heat exchangers
Seamless Grade 1 and Grade 2 tube for condensers, evaporators and shell-and-tube units, OD 20-60 mm.
Heat exchanger tube →
Desalination
Long-length Grade 2 and Grade 12 tube for MSF and MED evaporators and brine heaters.
Desalination plant →
Marine & seawater
Grade 2 plate, tube, fasteners and fittings for seawater cooling and marine hardware.
Marine service →
Which grade for which duty
| Duty | Grade normally specified | Why |
|---|---|---|
| Seawater cooling, marine hardware | Grade 2 | Commercially pure, resists chloride attack, weldable and widely stocked |
| Heat exchanger and condenser tubes | Grade 1, Grade 2 | Higher ductility for tube expansion into tube sheets |
| Hot brine, desalination evaporators | Grade 12 | Better crevice corrosion resistance than Grade 2 at elevated temperature |
| Reducing acids, hot chlorides | Grade 7 | Palladium addition extends resistance where Grade 2 is marginal |
| Load-bearing or high-strength parts | Grade 5 (Ti-6Al-4V) | 895 MPa minimum tensile where strength, not corrosion, governs |
Pairings above are the ones most often asked for. The grade that suits your medium, temperature and mechanical load is confirmed with the enquiry.
The full comparison of the two most frequently ordered grades is in the Grade 2 vs Grade 5 comparison.
What to include in an enquiry
An application page tells you which material usually fits. It does not tell us what you need. Four things shorten the quotation cycle more than anything else:
- The medium and temperature — seawater, brine, wet chlorine, a named acid at a concentration and temperature.
- The form and dimensions — plate thickness, tube OD and wall, bar diameter, or a drawing for machined parts.
- The standard and grade — ASTM B265, B338, B348, B381, B863 and the grade number.
- The documents — mill test report is standard; inspection certificates, PMI or third-party inspection must be stated up front.
If you are still deciding between grades, start with the grade selection guide.