Stainless Steel U-Bend Heat Exchanger Tube to TEMA/Drawing | Custom Geometry

Stainless Steel U-Bend Heat Exchanger Tube to TEMA/Drawing | Custom Geometry

Shaanxi Shangyou Stainless Steel Co., Ltd. supplies stainless steel u-bend heat exchanger tube to tema/drawing | custom geometry for buyers whose primary search intent is custom U-tube bundles and replacement exchanger tubing, not generic stainless or nickel-alloy stock. The page should be quoted against the selected standard edition, the equipment or component drawing and the governing design code. U-bent heat-exchanger tube supplied from a specified straight-tube grade, with bend geometry, heat treatment and inspection controlled by the equipment drawing.

The material decision should start with service conditions. The corrosion and temperature capability comes from the selected tube grade; the purchasing risk is usually geometry, wall thinning, ovality and bend-zone condition. ASTM A688 may be relevant to austenitic feedwater-heater tubes, but it is not a universal U-bend standard; use the actual straight-tube standard and equipment specification. This comparison belongs in the enquiry stage because a higher alloy name does not automatically deliver the lowest life-cycle risk.

A complete RFQ needs product form, grade/UNS, ordered condition, dimensional basis, tolerances, quantity and inspection level. RFQ must state OD, wall, straight-leg lengths, centerline bend radius, tangent locations, leg tolerance, plane-of-bend tolerance and quantity by bend radius. For pressure-containing products, the material standard controls product quality; it does not replace pressure-design calculations, corrosion allowance or code approval.

Manufacturing and documentation must remain connected. Mandrel/rotary draw or approved U-bending route. Bends must be identified by radius and protected against mixing during bundle preparation. The baseline verification plan is: Dimensional template check, ovality and wall-thinning verification, hydrostatic/air-under-water/NDE as specified, plus eddy current after bending when required. Any supplementary requirement—PMI extent, UT class, eddy-current acceptance, corrosion testing, grain size, roughness, cleanliness or third-party inspection—must appear in the PO before production.

Fabrication guidance: Weldability depends on the base grade and whether field closures are required. Keep carbon-steel tooling contamination away from wetted stainless surfaces. Selection boundary: A U-bend cannot be quoted from OD and wall alone. Missing radius, leg length, tolerance or post-bend test requirements creates a high risk of non-fit at assembly. Buyers should provide fluid composition, maximum and minimum temperature, pressure, design life, fabrication route and applicable code so the quotation can separate mandatory requirements from optional controls.

Standards, Dimensions and Supply Definition

Material and Selection Markers

Use note: Values above are concise identification/selection markers, not a replacement for the ordered ASTM/AWS chemistry table or the MTC.

Candidate Applications

• Shell-and-tube exchangers.
• Feedwater heaters where the applicable standard permits.
• Condensers.
• Replacement u-tube bundles.

Buyer Decision Boundary

ASTM A688 may be relevant to austenitic feedwater-heater tubes, but it is not a universal U-bend standard; use the actual straight-tube standard and equipment specification.

Processing, Inspection and Documentation

• Manufacturing: Mandrel/rotary draw or approved U-bending route. Bends must be identified by radius and protected against mixing during bundle preparation.
• Fabrication: Weldability depends on the base grade and whether field closures are required. Keep carbon-steel tooling contamination away from wetted stainless surfaces.
• Inspection: Dimensional template check, ovality and wall-thinning verification, hydrostatic/air-under-water/NDE as specified, plus eddy current after bending when required.
• Traceability: Keep heat/lot identity through cutting, machining, bending, welding, testing and packing.
• Documentation: Confirm MTC type, test reports, packing list, country-of-origin statement and third-party inspection before production.

RFQ Checklist

• Standard and adopted edition: Straight-tube material standard + TEMA RCB 2.31, DIN 28179 or customer drawing
• Grade / UNS: 304L / 316L / 321 / 347 and other approved grades / Grade-dependent
• Form and route: U-bent seamless or welded tube
• Dimensions, tolerances, quantity and unit basis
• Delivery/heat-treatment condition and surface/end finish
• Design code, service fluid/atmosphere, pressure and temperature
• Inspection/NDE, acceptance criteria, MTC and third-party witness points
• Marking, preservation, packing and delivery destination

Inquiry CTA

Frequently Asked Questions

1. What does Straight-tube material standard + TEMA RCB 2.31, DIN 28179 or customer drawing cover for this product? U-bent heat-exchanger tube supplied from a specified straight-tube grade, with bend geometry, heat treatment and inspection controlled by the equipment drawing. Always purchase to the edition adopted by the contract or project specification.
2. Is this product seamless, welded, forged, rolled or drawn? The PO must state the required route exactly: U-bent seamless or welded tube. Do not rely on a product photograph or a family name to establish the route.
3. How should buyers select 304L / 316L / 321 / 347 and other approved grades? The corrosion and temperature capability comes from the selected tube grade; the purchasing risk is usually geometry, wall thinning, ovality and bend-zone condition. ASTM A688 may be relevant to austenitic feedwater-heater tubes, but it is not a universal U-bend standard; use the actual straight-tube standard and equipment specification.
4. Which dimensions must be included in the RFQ? RFQ must state OD, wall, straight-leg lengths, centerline bend radius, tangent locations, leg tolerance, plane-of-bend tolerance and quantity by bend radius. Add quantity, unit basis, tolerances and any drawing-controlled geometry.
5. What heat-treatment or delivery condition is required? Straight-tube condition plus bend-zone treatment where the grade, radius, wall and project specification require it. The MTC and heat-treatment records should use the same grade and condition language as the PO.
6. Which inspection documents can be requested? Dimensional template check, ovality and wall-thinning verification, hydrostatic/air-under-water/NDE as specified, plus eddy current after bending when required. The final inspection scope must be agreed before order placement.
7. Is it suitable for the intended corrosive or high-temperature service? A U-bend cannot be quoted from OD and wall alone. Missing radius, leg length, tolerance or post-bend test requirements creates a high risk of non-fit at assembly. A material engineer should approve the final choice using actual service data.
8. What fabrication issues should be addressed? Weldability depends on the base grade and whether field closures are required. Keep carbon-steel tooling contamination away from wetted stainless surfaces. Use a qualified procedure and preserve heat/lot traceability after cutting or fabrication.
9. What are typical applications? Common candidate applications include shell-and-tube exchangers, feedwater heaters where the applicable standard permits, condensers, replacement U-tube bundles. These examples are not blanket design approvals.
10. What information is needed for a firm quotation? Send standard and edition, grade/UNS, form, dimensions, condition, quantity, delivery destination, inspection/NDE, documentation, packing and any third-party inspection or code requirement.