Each U bend tube of our range is rigorously quality checked by our team of talented professionals on every stage of production to deliver the clients defect free best quality products.
Tubes for heat exchangers are made of steel according to:
We bring forth an exclusive range of U-bend tubes, which are known for their superior quality and excellent functionality.
After U bend (cold forming), heat treatment of bending portion may be required. Temperature is controlled through the entire heat treated area by fixed and portable infrared pyrometers.
The semi-finished product for U bend tubes are heat exchanger tubes, manufactured and supplied according to DIN 28180 and ASTM A179.
Tube OD | Tube thickness | Bending Radius | U tube straight “leg” length | Straight tube before U bending |
Min. 12,7mm / Max. 31,75mm | Min. 0,70mm / Max. 4,19mm | Min. 1,5 x OD / Max. 1250mm | Max. 12500mm | Max. 27000mm |
At present Sunny Steel has purchased the equipment for production of the following product range:
Carbon & Alloy
Ferrite
Duplex
‘U’ bends are produced, controlled and measured fully in accordance with relevant standards.
All tubes are cut to the specified leg lenghts, ends deburred and the bores are internally cleaned with dried air.
We are equipped to carry out heat treatment of bends plus a minimum 150mm of leg.
Heat Treatment Equipment
All tubes are cut to the specified leg lenghts, ends deburred and the bores are internally cleaned with dried air.
Any type of packing is available according to customer need to worldwide destinations.
Any type of packing is available according to customer need to worldwide destinations.
With strong wood structure box packing by containers loading and shipping.
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.
Our U Bend Tube Tube-bending production line, installed at 2007. Solution annealing after bend will be process to lower the residual stress, and followed by hydrostatic testing and dye penetrant testing if required.
Stainless Steel U Bend Tube are widely used in heat exchanger systems. Heat exchanger equipment on the basis of stainless steel U-tube is essential in strategically important and critical fields nuclear and petrochemical machine building.
Surface condition Finished U Bend Tube shall be free of scale, without scratches after bending
3.1 Diameter of tube in the U bent portion
At the bent portion of a U-tube for R = 2 × D or greater, neither the major nor minor diameter of the tube shall deviate from the nominal diameter prior to bending by more than 10 %.
If less than 2 × D is specified, tolerances could be greater, provided that Entropie agrees prior to order.
3.2 Wall thickness in U bent portion
The wall thickness of the tube in the U-bent section shall not be less than value determined by the equation:
Where:
3.3 Tube leg length
In the case of U-tubes, the length of the tube legs as measured from the point of tangency of the bend and the tube leg to the end of the tube leg, shall not be less than specified, but may exceed the specified values by the amount given here below :
Leg length [mm]
Up to and incl. 6000 mm : -0 / +3.2 mm
Over 6000 mm to 9000 (incl) : -0 / +4.0 mm
Over 9000 -0 / + 4.8 mm
3.4 Difference in leg length
Stainless Steel Tube U Bend | U Bend Heat Exchanger TubesThe difference in lengths of the tube legs of a U tube shall not be greater than 1⁄8 in. = 3.2 mm unless otherwise specified.
3.5 End of tube : squareness
The end of any tube may depart from square by not more than:
0.25 mm for tubes up to 5/8” [15.9 mm]
0.40 mm for tubes higher than 5/8” [15.9 mm]
3.6 Leg spacing
The leg spacing measured between the points of tangency of the bend to the legs shall not vary from the value (2 R − specified tube outside diameter) by more than 1⁄16 in.[1.5 mm] where R is the center-line bend radius.
3.7 Bent portion curvature
The bent portion of the U-tube shall be substantially uniform in curvature, and not to exceed 6 1⁄16 in. [1.5 mm] of the nominal center-line radius.
3.8 Deviation from the plane of bend
Permissible deviation from the plane of bend (Fig. 1) shall not exceed 1⁄16 in. [1.5 mm] as
measured from the points of tangency.
The dimensions for heat exchanger tube in special grades may differ from the above,please contact us.
The advantage of the shell and tube design cannot be ignored. Each unit comes with:
‘U’ bends are produced, controlled and measured fully in accordance with relevant standards.
Material | Grade |
Carbon Steel | SA 179 / A 179 |
Carbon Steel | SA 210 / A 210 |
Carbon Steel | SA 334 / A 334 |
Stainless Steel | SA 213 / A 213 |
Duplex Stainless Steel | SA 789 / A 789 |
Copper & Cu Alloys | SB 111 / B 111 |
Titanium & Ti Alloys | SB 338 / B 338 |
(ASTM A 556 ]M - 88 / ASME 556 /ASTMA556M-88/ASME556)
ASTM A556 is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
Grade | C % | Si % | Mn % | P % | S % |
B2 | 0.27 max | 0.10 min | 0.29-0.93 | 0.030 max | 0.030 max |
C2 | 0.30 max | 0.10 min | 0.29-1.06 | 0.030 max | 0.030 max |
Mechanical Properties
Grade | Tensile Strength MPA | Yield Strength MPA | Hardness HRB |
B2 | 410 min | 260 min | 79 min |
C2 | 480 min | 280 min | 89 min |
Each U bend tube of our range is rigorously quality checked by our team of talented professionals on every stage of production to deliver the clients defect free best quality products. These U bend tubes can be custom designed in various diameters as per the requirements of our clients.
Heat-exchanger equipment on the basis of seamless stainless U-tubes is essential in strategically important and critical fields — nuclear and petrochemical machine building.
Item | Condition (when) | Tolercance |
---|---|---|
Nominal bend radius ≤ 2 x nominal OD | less than or equal to 12% | |
Ovality | 2 x nominal OD < Nominal bend radius ≤ 4 x nominal OD | less than or equal to 10% |
Nominal bend radius > 4 x nominal OD | less than or equal to 5% | |
Nominal bend radius ≤ 2 x nominal OD | 0.75 x nominal wall | |
Mimimum wall thickness | 2 x nominal OD < Nominal bend radius ≤ 4 x nominal OD | 0.8 x nominal wall |
Nominal bend radius > 4 x nominal OD | 0.9 x nominal wall | |
Nominal bend radius ≤ 8" (200mm) | +/-3/64"(1mm) | |
Bending Radius | 8" (200mm) < Nominal bend radius ≤ 16" (400mm) | +/-1/16"(1mm) |
Nominal bend radius >16" (400mm) | +/-5/64"(1mm) | |
Disrance between legs | Max 1/16"(1.5mm) | |
Wall thinning of bending area | Max 17% | |
Difference between leg lengths at the ends | Leg length ≤ 16' (4.88m) | +1/8"(3mm) |
Leg length > 16' (4.88m) | +3/16"(5mm) | |
Deviation from plane of bend | ≤ 3/16"(1.5mm) | |
Flattening on bend | ≤ 10% nominal diameter | |
Straight leg length | ≤5m | +1/8"(3mm) |
>5m | +3/16(5mm) | |
Total tube length including radius | ≤6m | +3/16(5mm) |
>6m | +5/16"(8mm) |
Standards usually required to establish U bend tube tolerances:
There are different varieties of pipe fittings made of various materials and available in various shapes and sizes.
Our team is highly trained and experienced in servicing and producing all types of steel supplies.