Titanium - flange

Three most commonly used titanium flange grades:

1. Gr2 (Industrial pure titanium)

◦ Applications: General corrosion resistance, seawater, brine, weak acids and alkalis, most chemical media

◦ Temperature: -196℃～315℃

◦ Most commonly used, highest cost-performance ratio

2. Gr7 (Ti-0.2Pd) Palladium titanium

◦ Applications: Strong reducing acids (dilute hydrochloric acid, dilute sulfuric acid, wet chlorine)

◦ More corrosion resistant than TA2, does not absorb hydrogen, does not become brittle

◦ Essential for chlor-alkali, pickling, and PTA applications3. Gr12 (Ti-0.3Mo-0.8Ni)

◦ Applications: Medium-strong acids, high temperature, crevice corrosion

◦ More resistant to high temperature and crevice corrosion than TA9

◦ Commonly used in petrochemical, high-temperature brine, and seawater desalination industries

II. Industry-specific recommendations:

1. Chlor-alkali/Chemical (wet chlorine, hydrochloric acid, brine)

• Recommended grade: Gr7 1. **Preferred:** Gr2

• Flange Type:

◦ Piping Connection: Plate Welded Flange (PL)

◦ Equipment Port/High Pressure: Weld Neck Flange (WN)

◦ Sealing Face: Raised Face (RF) / Raised Face (MFM)

2. **Seawater, Seawater Desalination, Offshore Platforms:**

• Grade: Gr2 or Gr12

• Type:

◦ Seawater Piping: PL Plate Welded Flange

◦ High Pressure/Large Diameter: WN Weld Neck Flange

◦ Sealing: RF Raised Face

3. **Oil & Gas, Hydrogen Sulfide Containing, High Salt

• Grade: Gr12

• Type:

◦ High Pressure: WN Weld Neck Flange

◦ Sealing: RJ Ring Joint (High Pressure) or MFM Raised Face

4. **Pharmaceuticals, Food, Pure Water, High Cleanliness:**

• Grade: Gr2

• Type:

◦ Sanitary Grade: Quick-Connect Flange / Flat Plate Flange

◦ General Piping: PL Flat Welding

5. Vacuum, High Temperature, Heat Exchangers

• Grade: Gr2

• Type: WN Neck Welded Plate or SO Neck Flat Welded Plate
III. How to Choose Flange Type (Simplest Rule of thumb)

• Low Pressure, Normal Temperature, General Piping → PL Plate Flat Welding Titanium Flange

• High Pressure, High Temperature, Equipment Pipelines → WN Neck Welded Plate Titanium Flange

• High Pressure, High Toxic/Flammable/Explosive → WN + RJ Ring Connection

• Cleanroom, Medical → Sanitary Quick-Installation/Flat Plate

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Titanium flanges offer key advantages: superior corrosion resistance, high strength and lightweight design, high temperature resistance, and fatigue resistance, making them ideal for pipe and equipment connections in highly corrosive, high-temperature, high-pressure, and extreme operating conditions.

I. Chemical Industry/Chlor-Alkali (Most Mainstream)

• Chlor-alkali electrolyzers, brine/wet chlorine/hydrochloric acid pipelines, PTA units, fine chemical reactors

• Vacuum salt production, flue gas desulfurization (strong acid/high chloride ion)

• Resistant to pitting/stress corrosion, service life several times longer than stainless steel

II. Oil/Natural Gas/Refining

• Sulfur-containing crude oil processing, oil and gas extraction, offshore platforms, sulfur-containing wastewater pipelines

• High temperature and high pressure (180℃/3.5MPa), high salinity/hydrogen sulfide environment

III. Marine Engineering/Shipbuilding/Seawater Desalination

• Seawater pipelines, deep-sea drilling platforms, submarine pressure hulls, seawater desalination units

• Resistant to seawater/salt spray, anti-biofouling, deep-sea high pressure (≥100MPa)

IV. Energy/Nuclear Power/New Energy

• Nuclear reactor cooling systems, nuclear waste treatment (radiation resistant/high temperature resistant)

• Hydrogen energy storage and transportation, solar thermal/photovoltaic, marine propulsion systems

V. Aerospace/Military Industry

• Aircraft hydraulic/fuel/engine piping, rocket propellant systems, satellite piping

• Lightweight + high strength, significant weight reduction

VI. Pharmaceutical/Food/Precision Instruments

• Pharmaceutical pure water/sterile piping, bioreactors, food-grade fluid systems (biocompatible)

• High cleanliness, no leaching, corrosion resistance

VII. Other Extreme Operating Conditions

• High temperature and high pressure equipment, vacuum systems, pump and valve matching, corrosive medium storage tank inlets