A single tube sheet with every tube bent into a U and returned to the same face — each tube expands independently, making this the structural type of choice for the highest pressure and temperature services.
| Structural Principle | Single tube sheet; every tube bent into a U-shape and returned to the same face |
| Typical Diameter Range | 150 mm – 2200 mm |
| Typical Thickness Range | 20 mm – 200 mm (highest-pressure services) |
| Thermal Expansion Handling | Each tube expands independently along its own U-bend — no expansion joint needed |
| Mechanical Cleaning Access | Tube-side limited near the bend radius; shell-side accessible for bundle pull |
| Governing Codes | TEMA (Class R most common), ASME Section I & VIII |
U-tube designs are the default for the highest-pressure boiler and refinery service, so alloy and stainless grades dominate real orders.
Boiler service typically involves the highest pressures and largest temperature swings in industrial heat exchange, and U-tube design handles both without an expansion joint or floating head — fewer mechanical components at the highest-stress operating conditions means fewer potential failure points.
Yes, though it's more involved than a straight-tube replacement since the U-bend geometry constrains access. Outer-row tubes are generally easier to pull and replace than inner-row tubes, which is a factor considered during bundle layout design.
Yes — the minimum bend radius for a given tube OD sets a practical floor on how close adjacent U-bend pairs can sit, which factors into the tube count and pitch calculation differently than a straight-tube fixed or floating design.
Every enquiry is checked against governing code, material compatibility and manufacturing feasibility before a quote is issued. Use our product, material, grade and standards guides to freeze the RFQ — then confirm with engineering.
Send your diameter, material, pressure class and quantity — we'll confirm thickness and price.