Gr2 Titanium Tube for Seawater Desalination Equipment

Desalination plants make fresh water from seawater. The problem is seawater is corrosive. It eats stainless steel. It pits copper alloys. It scales up and fails.

Gr2 titanium tube for seawater desalination equipment solves that. No pitting. No crevice corrosion. No scaling problems like some alloys. Just tube after tube after tube of clean, corrosion-free service.

Multi-stage flash (MSF). Reverse osmosis (RO). Multiple-effect distillation (MED). Any desalination process that moves hot brine needs this tube.

Grade 2 is pure titanium. Not alloyed. Not complicated. Just titanium with good strength and excellent corrosion resistance.

In desalination, the brine is hot. 40°C to 120°C depending on the process. Chlorides are concentrated. Oxygen levels vary. Stainless steel fails. Copper-nickel erodes. Grade 2 titanium doesn't care.

Gr2 titanium tube for seawater desalination equipment gives you:

Zero corrosion allowance. No wall thinning over time. No pitting in stagnant or flowing brine. No stress corrosion cracking. No galvanic issues with other titanium components.

Other grades exist. Grade 7 adds palladium. Grade 12 adds moly and nickel. But for most desalination service, Gr2 is enough. And Gr2 costs less.

Common dimensions for desalination

Tolerance: OD ±0.08mm. Wall ±10%. Length +5mm / -0mm.

Walk through any large desalination plant. You'll find Gr2 titanium tube for seawater desalination equipment in:

• Brine heaters. Hot brine on one side. Steam on the other. Tubes take the thermal stress and corrosion.
• Heat recovery sections. Multiple stages. Brine gets cooler as it goes down. Tubes see varying temperatures but always chlorides.
• Reject coolers. Final stage before brine goes back to the sea. Still corrosive. Still needs titanium.
• Condensers. Fresh water side and brine side. Titanium keeps them separate.
• Inlet and outlet piping for membrane systems. RO plants use titanium for high-pressure piping.

One place you don't use Gr2? Very hot reducing acid conditions in cleaning cycles. Some plants use acid cleaning. If the acid is hot and concentrated, Gr2 may attack. But that's cleaning, not normal operation.

Three reasons.

First, no corrosion allowance. Steel and stainless tubes need extra wall thickness. They corrode from the inside. Titanium doesn't. Thinner wall means more tubes per shell. More surface area. Better heat transfer.

Second, no pitting. Stagnant seawater sits in idle exchangers. Stainless pits in stagnant conditions. Titanium doesn't. Start up after a shutdown. No surprise leaks.

Third, long life. A stainless tube bundle in a desalination plant lasts 5-8 years. Copper-nickel lasts 10-12. Gr2 titanium lasts 20+ years. Some plants have titanium bundles still running after 30 years.

Gr2 titanium tube for seawater desalination equipment costs more upfront. Over the life of the plant, it's cheaper than replacing carbon steel every 5 years.

Desalination heat exchangers use tube-to-tubesheet welds. Titanium tubes welded to titanium tubesheet.

Rules are the same as any titanium welding. Clean. Argon purge. No contamination.

For Gr2 titanium tube for seawater desalination equipment, we supply tube ends clean and beveled. Tubesheet holes should be clean and dry.

Weld from the tubesheet face. Use ERTi-2 filler. Purge the tube side with argon. The weld should come out silver or light straw. Blue or purple means bad shielding.

If you're retubing an old exchanger, remove the old tubes carefully. Don't damage the tubesheet holes. Clean the holes before welding new tubes.

Some desalination designs use roller expansion instead of welding. Or expansion plus welding.

Titanium work-hardens. Use controlled rolling pressure. Too little and the tube leaks. Too much and you crack the tube end.

Lubricate the roller. Use a torque-controlled expander. Stop when you hit the target torque. Don't guess.

For Gr2 titanium tube for seawater desalination equipment, we can supply tube ends with light lubrication for rolling. Tell us if you're rolling or welding.

ASTM B338 requires:

• Hydrostatic pressure test. Every tube.
• Flattening test. Sample per lot.
• Flaring test. Sample per lot.
• Eddy current or ultrasonic NDT.

We provide full documentation. Heat number traceable. Mill test reports. Third-party inspection available (DNV, ABS, Lloyds, TÜV).

Desalination is hard on equipment. Hot brine. High chlorides. Stagnant periods. High flow.

Gr2 titanium tube for seawater desalination equipment takes all of it. No corrosion. No pitting. No wall loss.

Gr2 for most desalination. Seamless or welded depending on budget. Tested. Certified. Traceable.

Lasts 20+ years. Costs less over the plant life.