Product Specification

ASME SA266 Gr.2N Forged Carbon Steel Tube Side Flange for Heat Exchanger

ASME SA266 Gr.2N tube side flange is a forged carbon steel pressure component manufactured for shell and tube heat exchangers and other pressure vessel equipment.

The flange is installed on the tube-side connection or channel-side assembly according to the heat exchanger design. It provides a bolted connection between mating components and allows equipment sections to be assembled and disassembled for inspection, maintenance, or tube bundle servicing.

Unlike standard pipeline flanges, heat exchanger tube side flanges may require customized outside diameter, thickness, bolt hole arrangement, hub geometry, bore dimensions, and sealing surfaces. Therefore, the final dimensions are normally manufactured according to approved engineering drawings and project specifications.

ASME SA266 covers carbon steel forgings for pressure vessel components, and Grade 2 is one of the commonly specified grades for forged pressure equipment components.

Material and Standard

ASME SA266 Gr.2N Carbon Steel Forging

Material Standard: ASME SA266 / ASTM A266
Material Grade: Grade 2N
Material Type: Carbon Steel Forging
Product Type: Tube Side Flange
Manufacturing: Forging and Machining
Application: Shell and Tube Heat Exchanger

The designation Gr.2N generally indicates Grade 2 material supplied in the normalized condition, subject to the applicable material and purchase requirements.

For Grade 2 material, the applicable chemical composition and mechanical property requirements should be verified against the specified edition of ASME SA266 and the project documentation. Existing product data for this grade identifies Grade 2 as a carbon steel forging used for pressure vessel components and heat exchanger parts.

Tube Side Flange Function

Heat Exchanger Connection Component

In a shell and tube heat exchanger, the tube-side flange forms part of the connection between the channel, tube-side cover, tubesheet assembly, or other mating pressure components, depending on the exchanger configuration.

The flange design may include:

• Outer flange diameter
• Bore diameter
• Flange thickness
• Bolt hole quantity and position
• Gasket seating surface
• Raised or machined sealing face
• Hub or neck geometry
• Customized connection dimensions

The actual configuration should follow the heat exchanger general arrangement drawing and pressure equipment design requirements.

Maintenance and Equipment Assembly

A bolted flange connection allows the connected section to be removed when the equipment requires:

• Tube bundle inspection
• Internal cleaning
• Tube maintenance
• Gasket replacement
• Equipment inspection

The connection design, bolt load, gasket type, and sealing surface requirements should be determined according to the applicable equipment design specification.

Manufacturing Process

Carbon Steel Forging

SA266 Grade 2 carbon steel is forged into a flange blank with sufficient machining allowance according to the required component dimensions.

The forging process is suitable for manufacturing pressure equipment components with customized geometry.

Heat Treatment

The Gr.2N designation is associated with a normalized supply condition.

The final heat treatment procedure should comply with the applicable material specification, component size, and purchase requirements.

Rough and Finish Machining

Machining operations may include:

• Outside diameter machining
• Bore machining
• Facing
• Bolt hole drilling
• Gasket seating surface machining
• Hub or neck machining
• Edge preparation

Final Inspection

The finished flange can be inspected according to project requirements for:

• Dimensions
• Material identification
• Surface condition
• Mechanical properties
• Heat treatment records
• Non-destructive examination when specified

Product Specifications

Available Specifications

The flange can be manufactured according to customer drawings and equipment specifications.

For custom heat exchanger flanges, the applicable dimensional standard should be determined by the actual flange configuration and project specification rather than automatically applying a standard piping flange dimension. The existing product page also identifies the component as customizable for heat exchanger use.

Applications

Shell and Tube Heat Exchangers

ASME SA266 Gr.2N tube side flanges can be used in shell and tube heat exchanger assemblies where a forged carbon steel flange is specified for the tube-side or channel-side connection.

Typical equipment includes:

• Shell and tube heat exchangers
• Condensers
• Coolers
• Process heat exchangers
• Industrial thermal equipment

Pressure Vessel Equipment

SA266 carbon steel forgings are also used for pressure vessel components manufactured according to applicable engineering and project requirements.

Petrochemical and Energy Equipment

Depending on the specified material selection and operating conditions, the component may be used in:

• Petrochemical equipment
• Oil and gas processing equipment
• Power generation equipment
• Industrial process systems

Quality Control and Inspection

Material Verification

Inspection may include:

• Chemical composition analysis
• Mechanical property testing
• Heat number traceability
• Material certificate review

Dimensional Inspection

Key inspection parameters may include:

• Outside diameter
• Bore diameter
• Flange thickness
• Bolt hole diameter
• Bolt hole position
• Facing dimensions
• Flatness
• Machining tolerances

Non-Destructive Testing

According to project requirements, inspection may include:

• Ultrasonic Testing (UT)
• Magnetic Particle Testing (MT)
• Liquid Penetrant Testing (PT)

Additional examination requirements can be applied according to the pressure equipment specification