U-bend tubes are widely used in heat-exchanger systems. Heat-exchanger equipment on the basis of seamless stainless U-tubes is essential in strategically important and critical fields — nuclear and petrochemical machine building.
A tube-bending line, that was installed at our factory in the end of 2005, allows to produce U-tubes
as per such standards:
1. ASTM A688/A688M
2. ASTM A803/A803M
3. ASTM A556/A556M, ASME SA-556
4. ASME SA-179/SA213
Carbon & Alloy
A179 T11 T12 T22
TP 304 /
304L TP 316 /
316L TP 316Ti TP 317 /
317L TP 321 TP347
N06600 N08020 N00880 N08825 N08904
Tubes of other alloys and steel grades can be produced upon agreement.
Technical requirements Straight tubes for bending: ASTM/ASME SA 179; SA 213; ASTM B 163; ASTM B 729; ASTM B 407; ASTM B 423; ASTM A 789 U-bend Tubes: -TEMA RCB 2.31 Standards of the Tubular Exchanger Manufacturers Association (9th edition). -ASTM A688 Standard specification for welded tubes of austenite corrosion resistant steel grade designed for feed water boilers. -ASTM B163 Standard technical requirements for tubes of nickel and nickel alloy for condensers and heat exchangers. -Customer specifications.
BENDING RADIUS: from 1.5 OD to 1250 mm. When ordering tubes with R≤1.5D it is necessary to agree precision of geometrics. STRAIGHT TUBES MAXIMUM LENGTH (before bending): 26000 mm. LEG LENGTH: min 1 meter, max 10.5 meters (for max R=1250 mm) Note: other sizes are available upon agreement. HEAT TREATMENT: Stress Relieved after U bending. HYDROSTATIC TEST: maximum test pressure 600 bar, soaking 10 sec. with demineralized water. Compressed air cleaning after hydro-test. Marking: before bending by marking machine all over the tube length (bent section after heat treatment without marking). Marking is also possible after bending on the straight parts of U-bent tube. Packaging: closed wooden boxes of corresponding dimensions for each tube length, radius, diameter, according to PO requirements or in bundles wrapped in polyethylene film with plastic clamping spacers on each tube.