Application and Advantages of Titanium Flanges in the Environmental Protection Field

In summary, due to their excellent corrosion resistance, high strength, long service life, and exceptional eco-friendliness, titanium flanges are becoming critical components in demanding environmental engineering projects, especially in scenarios involving corrosive media and requiring long-term equipment stability.

I. Specific Applications of Titan Flates in Environmental Protection

Titanium flanges, as essential connecting components in piping systems used to join pipes, valves, and equipment, ensuring system sealing and structural integrity, are primarily used in the following highly corrosive environments within the environmental sector:

1. Flue Gas Desulfurization (FGD) Systems

   • Application Scenario: Tail gas treatment systems in thermal power plants, waste incineration plants, and metallurgical/chemical industries. These flue gases contain large amounts of sulfur dioxide (SO₂), chlorides (e.g., HCl), fluorides, and moisture, creating highly corrosive acidic environments (e.g., dilute sulfuric acid, sulfurous acid).

   • Role: Titanium flanges are used to connect absorbers, ducts, spray systems, and recirculation piping within FGD systems. They are critical connection points ensuring the entire corrosive gas handling system remains leak-free.

2. Industrial Wastewater Treatment Systems

   • Application Scenario: Treatment plants for high-concentration wastewater from chemical, pharmaceutical, electroplating, printing, dyeing, and paper industries. This wastewater often contains chloride ions (Cl⁻), strong acids (e.g., hydrochloric acid, sulfuric acid), strong alkalis, oxidizing chemicals, etc.

   • Role: Titanium flanges connect reaction kettles, sedimentation tanks, filtration units, advanced oxidation (e.g., ozone treatment) pipelines, and wastewater conveyance pipes, particularly in areas requiring resistance to chloride-induced stress corrosion cracking (SCC).

3. Seawater Desalination Systems

   • Application Scenario: Seawater desalination plants using reverse osmosis (SWRO) and multi-effect distillation (MED). Seawater is a natural strong electrolyte containing high concentrations of chloride ions, which are extremely corrosive to most metals.

   • Role: Titanium flanges are widely used in seawater intake pipes, pretreatment systems, connections for high-pressure reverse osmosis membrane housings, and connecting parts for heat exchange systems in distillation units.

4. Hazardous Waste Treatment

   • Application Scenario: Treatment facilities for hazardous waste liquids containing acids, alkalis, or organic solvents.

   • Role: Ensure absolute safety and reliability at pipeline connection points during the transport and treatment of these extremely hazardous media, preventing leaks of harmful substances.

5. Hydrometallurgy and Chemical Processing

   • Application Scenario: Although more industrial, their environmental end-of-pipe treatment is closely related. Used in processes involving chlorine, hydrochloric acid, aqua regia, etc., for reactions and extraction.

   • Role: Used for connections between equipment and piping, ensuring the containment of production and recycling processes.

II. Core Advantages of Titanium Flanges

Titanium (especially commercial pure grades like GR2, GR1) offers irreplaceable advantages compared to other materials like stainless steel (e.g., 304, 316L), duplex steel, and nickel-based alloys (e.g., Hastelloy) in environmental applications:

1. Superior Corrosion Resistance (Core Advantage)

   • Resistance to Chloride Ion Corrosion: This is titanium's most prominent advantage. Titanium has innate immunity to pitting and stress corrosion cracking (SCC) caused by chloride ions, whereas stainless steel is very vulnerable. This grants it an extremely long service life when handling seawater, chloride-containing wastewater, and flue gas (containing HCl).

   • Resistance to Acidic Environments: Titanium performs well in oxidizing acids (e.g., nitric acid, chromic acid) and weak reducing acids. Although it corrodes faster in non-oxidizing acids (e.g., pure hydrochloric acid, sulfuric acid), in FGD environments, the presence of oxidants (e.g., SO₂, O₂) prompts the rapid formation of a dense, stable titanium oxide (TiO₂) passive film on the surface, effectively halting further corrosion.

   • Resistance to Crevice Corrosion: Flange connections are prone to crevice corrosion. Titanium's resistance to crevice corrosion in high-chloride environments is far superior to stainless steel.

2. Excellent Mechanical Strength and Light Weight

   • Titanium has high strength but a density (~4.51 g/cm³) much lower than steel (~7.9 g/cm³). This means for the same strength requirements, titanium flanges can be made lighter, helping reduce system load, which is particularly advantageous for large absorbers or elevated ducts.

3. Long Service Life and Low Lifecycle Cost (LCC)

   • Although the initial material cost of titanium is higher than stainless steel, its virtually maintenance-free nature, extremely low failure rate, and超长 service life (20-30 years or more, whereas stainless steel might need replacement in a few years) significantly reduce the total cost of ownership.

   • It avoids massive production losses and secondary investments caused by downtime for replacement and repairs, making it highly economical in the long run.

4. Excellent Eco-friendliness and Safety

   • Biocompatibility: Titanium is non-toxic and harmless, with good compatibility with human tissue and the environment. Even if corrosion products enter the system, they do not cause secondary pollution, making it very suitable for water treatment where effluent quality is critical.

   • High Safety: Its high reliability greatly reduces the risk of pipeline failure and leakage of hazardous substances due to corrosion, which is crucial for protecting the environment and operator safety.

5. Good Fabrication Properties

   • Titanium flanges can be manufactured through forging, casting, etc., meeting various pressure ratings (PN6-PN100) and standards (GB, ASME, JIS, etc.).

III. Comparison with Other Materials