U bent cold drawn seamless tubes for heat exchangers used widely in chemical, petrochemical, and energy plants

1. U bend Tube Bundle reference standards and steel grades

“U” bent tubes for heat exchangers can be supplied in accordance with ASME SA556, ASME SA179, ASME SA192, ASME SA213, ASME SA688, ASME SA803

Reference standards and Steel Grades: 304/304L Austenitic, 316/316L Austenitic, 2205 Duplex, 2507 Duplex,439 Ferritic

ASTM A556 Gr. A2 - B2 - C2, ASME SA556 Sect.II Gr. A2 - B2 - C2

“U” Bent tubes in accordance with the standards detailed in table 1, part A can be requested. 

The bent area can be subject to stress-relieving heat treatment by the joule effect in an inert atmosphere.

- Minimum radius treated = 28 mm.

- Maximum radius treated = 750 mm.

2. U bend Tube Bundle Dimensions and lengths

Tubes with the following external diameters in mm can be bent a upon agreement: 15,8 - 16,0 - 17,0 - 18,0 - 19,05 - 20,0 - 21,3 - 25,4 - 26,7 - 31,8 -38,1.

The minimum feasible radius is  1,5 x external diameter

The maximum feasible radius is 1500 mm.

3. U bend Tube Bundle Tolerances

Tolerances (diameter and wall thickness) according to ASTM A 556 or given in the standards detailed in table 1 point A are respected.

Bending tolerances. The tolerances stipulated in ASTM A 556 are respected.

Minimum wall thickness tolerances in the bent area conforming to the TEMA standard "Class R heat exchangers" can be requested or in accordance with specific requests.

4. U bend Tube Bundle Checks and test

All the mechanical and technological tests stipulated in the cited standards are carried out. 

Leak tightness test: electromagnetic test (Eddy Current) is performed on straight tubes. Hydrostatic test on bent tubes is performed only if expressly requested, specifying the test pressure

5. U bend Tube Bundle Standard Technical Range

OD 9.5mm  - 38.1mm

WT up to 6.35mm

Bending radii 1.25 x OD up to 1700mm

Bends can be supplied in accordance with TEMA R / ASTM SA/A556

Leg length up to 15000mm

6. U bend Tube Bundle Test

Heat treatment where required by electric furnace or direct resistance

Hydrotesting up to 10,000 psi

7. U bend Tube Bundle Additional Testing

Dye penetrant of U bend area

PMI testing

Heat Treatment

We are equipped to carry out heat treatment of bends plus a minimum of 150mm of the leg.

Heat treatment equipment is computer controlled with the added facility of data recording.

An argon protective atmosphere is used inside stainless and special alloy tubes during heat treatment.

We can provide all types of annealing; solution annealing and stress relieving.

Measuring, Cutting, Deburring, and Cleaning

U bends are produced, controlled, and measured fully in accordance with relevant standards.

All tubes are cut to the specified leg lengths, ends deburred and the bores are internally cleaned with dried air.

8. U bend Tube Bundle Packing

For road freight in timber fingers or skids.

In strong open or closed wooden boxes depending destination.

Each bundle is protected with plastic sheets.

Customers can provide their own packing or Salem can prepare a packing plan.

Detailed packing lists are attached to wooden cases to give quick and clear identification of contents.

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