ASME SA266 Gr.2N Carbon Steel Heat Exchanger Tubesheet for Industrial Pressure Equipment

Yuhong Group Co., Ltd. delivers heavy-duty industrial process equipment and core components, supplying global markets through www.tema-heatexchanger.com.

With extensive expertise in the fabrication of shell-and-tube heat exchangers, pressure vessels, and air coolers, we provide critical components engineered to rigorous international standards. Our core manufacturing portfolio encompasses complete tube bundles, U-tubes, seamless heat exchange tubes, finned tubes, and precision-machined pressure vessel internals including tube sheets, baffle plates, and channel heads.

As specified by ASME Section II, SA 266 (Grade Gr. 1, Gr. 2, Gr. 3, or Gr. 4) carbon steel forgings are engineered specifically for pressure vessel components. The chemical composition guarantees mechanical integrity under high-stress operating environments:

Fabricating a heavy-duty SA 266 tubesheet requires stringent mechanical processing to prevent operational failure in shell-and-tube heat exchangers.

• Forging and Dimensional Tolerances: Components are produced via heavy hydraulic forging to ensure a refined grain structure, followed by CNC deep-hole drilling and precision reaming. Hole diameter tolerances are maintained within ±0.05 mm, and ligament width variations are kept below 0.1mm to guarantee seamless tube-to-tubesheet joint integrity.
• Mandatory Non-Destructive Examination (NDE): Every tubesheet undergoes 100% Ultrasonic Testing (UT) in accordance with ASME SA-388 to detect internal laminations, inclusions, or micro-fissures. Surface defects are verified via Magnetic Particle Testing (MT).
• Critical Control Points: Thermal stress-relieving post-machining is strictly enforced to eliminate residual stresses induced by multi-axis drilling. Surface roughness on gasket seating faces is strictly controlled between 1.6μm to 3.2μm Ra to ensure reliable joint sealing under cyclic thermal loads.

To support complete thermal design and pressure containment, Yuhong Group supplies integrated material packages matching your specific process operating window:

• Complementary Material Grades: Beyond SA 266 carbon steel, we supply tubesheets in alloy steels, stainless steels (SA 240 304L/316L), and non-ferrous overlays (such as titanium, copper-nickel, and Inconel cladding).
• Integrated Assembly Support: We match our tubesheets directly with our precision-drawn seamless heat exchange tubing, U-tubes, and engineered baffle layouts, ensuring strict pitch alignment and zero mismatch during final bundle insertion.

The SA 266 tubesheet serves as the primary structural divider and pressure boundary in heavy industrial thermal systems, operating across specific industrial environments:

• Petroleum Refining: Hydrotreaters, catalytic crackers, and crude oil fractionating tower overhead condensers operating at design pressures up to 25 MPa and temperatures up to 400 °C.
• Petrochemical Processing: Ethylene cracking units, synthesis gas coolers, and high-pressure exchangers handling corrosive hydrocarbon streams.
• Power Generation: High-pressure feedwater heaters and surface condensers requiring high resistance to thermal shock and mechanical fatigue.

• Parametric Structural Integrity: Designed in strict compliance with ASME Section VIII, Division 1 or Division 2 standards and TEMA Class R, C, or B mechanical requirements, calculating exact thickness based on design pressure, shell diameter, and ligament efficiency.
• Precision Groove Machining: Custom multi-groove (shear-stress relief grooves) machining inside tube holes to optimize hydraulic or roller expansion performance, preventing tube pull-out under severe thermal expansion cycles.
• Custom Fabrication Services: Full-service CNC machining based on customer-provided thermal rating sheets (HTRI reports) or detailed CAD/SolidWorks manufacturing drawings.