Stainless Steel Pipe Fittings

U Bend Stainless Steel Tubes By yaang.com

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U Bend Stainless Steel Tubes By yaang.com

U Bend Stainless Steel Tubes are manufactured in our plant as per the customer requirements. Bends can be Heat Treated in accordance with Clients’ requirements followed by hydrostatic testing and dye penetrant testing if required.

U bend tubes are widely used in heat-exchanger systems. Heat exchanger equipment on the basis of stainless U-tube is essential in strategically important and critical fields nuclear and petrochemical machine building.

U tubes heat exchangers Designed for high temperature applications, especially steam condensing or hot oil systems. Thïs model is selected when differential expansion makes a fixed tube sheet exchanger unsuitable and when conditions preclude a floating head type (HPF) selection. 

Surface condition Finished U-tubes shall be free of scale, without scratches after bending.


Dimensional tolerances U tubes acc. to TEMA R.C.B.
Length of straight part -0/+5 mm 
Flattening (also called “ovality”) at the bend shall not exceed 10% of the nominal tube outside diameter.
Wall thickness in bending part acc. to TEMA RCB 2.31 Minimum tube wall thickness in the bend part (T min)T(min) ≥ (SW × (2×R + D))/( 2× (R+D)where: 
SW is smallest wall thickness D Nominal outside diameter R radius
Radius tolerance 1) for R 100 mm +/- 3 mm
2) for R ≥ 100 mm +/- 5 mm
Straightness tolerance max. 1,5 mm per 1 m
U-Tubes ends: plain, vertically cut to the tube axis
Tube-bending line, installed at 2007, will allow to produce U-tubes as per such standards:
1. ASTM A688/A688M-08
2. ASTM A803/A803M
3. ASTM A556/A556M, ASME SA556
4. ASME SA-688

Initial Length
Maximum lengths of 27000mm can be supplied on request

Dimensions
Tubes OD in mm can be bent upon agreement: 15,8 – 16,0 – 17,0 – 18,0 – 19,05 – 20,0 – 21,3 – 25,4 -26,7 – 31,8 -38,1

Bending radius
Minimum: 1.5×OD
Maximum: 1500 mm

Heat treatment of the bend
U bend tubes with a bending radius up to maximum of 1500mm can be heat treated on request
The basic Testing and processing:

1. High Pressure Hydrostatic Test:Minimum:10 Mpa-25Mpa.
2. Air Under Water Test After Bending
3. U Tubes Wall Thickness Test
4. Eddy Current Test before U bend Formed 
5. Ultrasonic Test before U bend Formed
6. Heat treatment to stress relieved 
7. Ball passing test
The below sizes are those most frequently used,other sizes can be produced upon request.
The dimensions for heat exchanger tubes in special grades may differ from the above,please contact us: sales@yaang.com .

Grade(UNS): Austenitic Stainless Steel:

304/304L/304H(1.4301/1.4306/1.4948); 316/316L(1.4401/1.4404); 316Ti(1.4571);

321(1.4541);309S (1.4833); 310S(1.4845); 317L(1.4438)321H(1.4878); 347H (1.4550); 

Duplex Stainless Steel:
S32001, S32003, S31500, 2205(1.4462); S32304,(1.4362);S31803,2507 (S32750),S32760(1.4501);S32101(1.4162);
Super Austenitic Stainless Steel: 904L, S30432, S31042, 6Mo (S31254, N08367) 
Nickel Base Alloys:
Alloy 20 (UNS N08020), Monel 200 (UNS 02200), Monel 400 (UNS N04400), Incoloy 800 (UNS N08800), Incoloy 800H (UNS N08810), Incoloy 800HT (UNS N08811), Incoloy 825 (UNS N08825),Inconel 600 (UNS N06600), 4J29, 4J36, GH3030, GH3039, C276 (UNS N10276)
Martensitic Stainless Steel:410(1.4006), 410S(1.4000), 420(1.4021)
Ferritic Stainless Steel:405(1.4002), 430(1.4016)

Outside Diameter: 6 – 830mm
Wall Thickness: 0.50 – 60mm
Standards(Norm): EN 10216-5DIN 17456, DIN 17458, DIN 2462, DIN 17455
GB/T14975; T14976; T13296; GB5310;
ASTM A213A269A312A511A789A790A928, A999, A1016, ASTM B161, ASTM B163, ASTM B165, ASTM B167, ASTM B338, ASTM B407, ASTM B423, ASTM B444,ASTM B619, ASTM B622, ASTM B626, ASTM B668, ASTM B677, ASTM B829
JIS G3459, JIS G3463, JIS G3446, JIS G3447, JIS G3448, JIS G3468
GOST 9940;GOST 9941;

Source: Zhejiang Yaang Pipe Industry Co., Limited (www.yaang.com)

Article Categories:
Steel Pipe

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