ASME SA336 F11 CL2 Alloy Steel Forgings Pressure Vessel Flange Tube Side Flange

ASME SA336 F11 CL2 Forged Alloy Steel Flange Pressure Vessel Flange

ASME SA336 is a material specification for forged steel components (e.g., flanges, fittings, valves) intended for high-temperature and high-pressure service in pressure vessels, boilers, and power plants. It covers requirements for chemical composition, heat treatment, mechanical properties, and testing of forgings. F11 Cl2 resists oxidation and sulfidation in high-temperature hydrocarbon or steam environments. This type of flange connects the tube bundle to the pressure vessel or piping system, and seals the process fluid (e.g., steam, hydrocarbons, corrosive media) under high pressure/temperature.

SA336 vs. A182: SA336 is generally for larger or custom forgings in pressure vessels, while A182 is standardized for piping.

Grade F11: A chromium-molybdenum (Cr-Mo) alloy steel with approximate composition:

• • 1.25% Chromium (Cr)

  • 0.5% Molybdenum (Mo)

  • Carbon, manganese, silicon, and other trace elements.

  • Provides excellent creep strength, oxidation resistance, and high-temperature performance (typically up to ~593°C / 1100°F).

Class 2 (Cl2): Indicates the heat treatment condition:

• Quenched and Tempered (Q&T): Enhances strength and toughness compared to Class 1 (normalized and tempered).

• Mechanical properties typically include:

  • Tensile Strength: ≥585 MPa (85 ksi)

  • Yield Strength: ≥380 MPa (55 ksi)

Comparison with Shell Side Flanges

• Tube Side vs. Shell Side:

  • Tube Side: Typically handles higher-pressure process fluids (e.g., steam, process gas).

  • Shell Side: Often lower pressure but larger flow area (e.g., cooling water).

  • Material requirements may differ based on fluid aggressiveness and temperature.

Industry-Specific Applications

• Oil & Gas: Metering crude oil in high-pressure pipelines (e.g., API 14.3/AGA-3 standards).

• Power Generation: Steam flow measurement in turbines (ASME PTC 6 compliant).

• Petrochemical: Ethylene/cracker unit feed lines (resists hydrogen embrittlement).

• Nuclear: Auxiliary cooling systems (ASTM A182 F5 is not for primary loops but used in secondary circuits).

• Boiler

• Pressure Vessel