Titanium for Desalination Plants

Where titanium sits in MSF and MED plant

Multi-stage flash and multiple-effect distillation plants both evaporate seawater, and both are hard on metals: hot, concentrated brine, high chloride, dissolved oxygen varying by stage, and continuous operation with expensive consequences for a tube leak.

• Brine heater tubes. The hottest, most concentrated duty in an MSF plant, and the place where Grade 12 rather than Grade 2 is most often considered.
• Heat recovery and heat rejection section tubes. Long runs of thin-wall tube at progressively lower temperature — the largest tube quantity in the plant.
• Evaporator vessels and tube supports. Where Grade 2 plate and structural sections are used.
• Vents, ejectors and condensate lines. Smaller quantities but the same corrosion logic.

Titanium's place is essentially uncontested here. Copper alloys suffer in hot brine; stainless steels fail by pitting and crevice attack. Thin-wall titanium tube has become the standard specification for these units.

Typical tube specification range

Sizes, testing arrangements and timing for a specific enquiry are confirmed in the quotation — please contact us for confirmation.

Grade 2 and Grade 12 in hot brine

This is the one place where the Grade 2 versus Grade 12 question is genuinely substantive rather than academic. Both are fine in ambient seawater. As brine temperature rises and crevice geometry appears — under tube supports, at the tube-to-tubesheet joint, beneath deposits — Grade 12's added molybdenum and nickel give it better resistance.

The conventional industry approach is to use Grade 2 for the cooler sections and upgrade to Grade 12 for the hot stages and brine heater. See Grade 12 titanium for the corrosion reasoning, and heat exchanger tube for the general tube specification.

Consolidated shipments

A desalination tube order is a shipping problem as much as a metallurgical one. Thousands of metres of thin-wall tube need to arrive usable, identifiable and countable.

• Container consolidation. Tube plus plate plus flanges can often be brought together into one full container load, subject to the sizes and quantities involved — we confirm this when quoting.
• Bundle-by-bundle identification. Bundles labelled so receiving inspection can reconcile each one against the packing list and heat records.
• Export casing. Long lengths cased to protect against deformation and moisture in transit.
• Partial shipments. Where a plant programme needs delivery by stage, split shipments can be planned rather than improvised.

An earlier example of the scale involved: a consolidated package of roughly twenty tonnes combining plate, bar and tube was quoted CIF Istanbul for a single buyer. That was one quotation rather than one completed contract, and it is cited here to show the size of package we put together, not as a reference project.

Packing methods and Incoterms are described in more detail on the packaging and shipping page.

Documentation and inspection

EPC-grade work expects the paperwork to be right. Typically that means heat-to-bundle traceability so each bundle maps to its melt, a full certificate set against the ordered standard, dimensional records, and third-party inspection attendance where the contract provides for it.

The documentary requirements should be listed on the first enquiry. They are far easier to build into production than to assemble afterwards.

What goes into the document set →

Enquiry template

Plant type:   MSF / MED / RO / other ______
Section:      brine heater / heat recovery / heat rejection / ______
Product:      titanium tube, seamless
Grade:        Grade 2 / Grade 12  (hot end? ______)
Standard:     ASTM B338 + revision ______
OD x wall:    ______ mm x ______ mm
Length:       ______ mm  tolerance ______
Quantity:     ______ metres total
Testing:      hydrostatic / eddy current / other ______
Documents:    MTC / third-party ______ / heat-to-bundle traceability yes / no
Destination:  port ______   Incoterm ______
Delivery:     required on site by ______

Frequently asked questions