Stainless U bend tubes
Stainless U bend tubes are made of stainless steel and are bent in a U-shape to redirect the flow of liquids or gases in a piping system.
U-shaped heat exchanger tubes are a type of shell and tube heat exchanger that have a tube bundle made of continuous tubes bent into a U-shape.
The bend side is free-floating and this helps in thermal expansion without requiring expansion joints. U-tube heat exchangers have a simple structure which makes them easy to manufacture and maintain. They are commonly used in shell and U-tube heat exchangers.
U bent heat exchanger tubes are used in various industrial applications for heat transfer between fluids, such as in boilers and condensers. U bent heat exchanger tubes are made from a variety of materials including stainless steel, titanium, and copper alloys depending on the application and environmental factors. They are typically designed to withstand high temperatures and pressures and are used in both liquid and gas applications.
Both ends of the U-tube are fixed on the same tube plate, and the shell and heat exchange tubes are separated. This allows the tube bundle to freely expand and contract without generating temperature difference stress, which is a problem that can occur in other types of heat exchangers.
U-shaped heat exchanger tubes have a simple structure which makes them easy to manufacture and maintain. They are commonly used in shell and U-tube heat exchangers, which consist of a cylindrical shell with U-shaped tubes inside. The U-tube design allows for better heat transfer efficiency, and the compact size of the U-shaped tubes means that the heat exchanger can be very powerful despite its small footprint.
Overall, U-shaped heat exchanger tubes are a popular choice for many industrial applications due to their simplicity, efficiency, and compact size.
U-tubes are made of precision straight tubes. These precision straight tubes are completed after cold rolling and bright annealing. In order to meet the technical conditions of our customers, every step of the process is strictly controlled.
U-tubes are mainly divided into two categories according to materials: stainless steel U-tubes and alloy steel U-tube
a...................The difference in length between two straight pipe sections
c..............The tangent spacing of the outer wall of the elbow
Da............nominal steel pipe outer diameter
E..............The distance between the outer diameters of the two straight ends
f...............the distance between the ends of the two straight ends
l............... straight tube length
Lg............. straight pipe section plus total length of pipe
Rm...........nominal bending radius
S.............nominal wall thickness
Smin.......The minimum wall thickness at the back of the elbow
t...............the bend deviates from the horizontal distance
So...........Standard minimum wall thickness
If requested by the customer, we add a straight pipe section with a minimum of 150mm according to the elbow.
Heat treatment is performed.
The computer controls the heat treatment furnace and records all the data.
The tube is filled with a protective gas - argon.
Outer diameter: 12.7-38 mm
The bending radius is from 1.5 times the outer diameter to 1250 mm. The outer diameter is over 28mm,
The minimum bend radius can be further discussed.
Straight pipe length is the shortest 1000mm
Straight pipe length up to 12000mm
The bending radius is below 1000mm and heat treatment is required.
U-tube heat exchanger is a kind of tube and shell heat exchanger, which belongs to petroleum and chemical equipment.
This kind of heat exchanger is named after the "U" shape tube. U-tube heat exchanger is composed of some main components such as tube box, shell and tube bundle. What's more, it is easy to dry after the U-tube heat exchanger hydrotest.
The most notable difference between U-tube heat exchangers and other shell-and-tube heat exchangers is the U-shaped configuration of the tubes. Key characteristics include:
Sunny Steel can manufacture U tube heat exchanger in accordance with the ASME standard, TEMA, and API for 1, 2, or 4 pass U tube heat exchanger, other special requirements are also available.
The semi-finished product for U bend tubes are heat exchanger tubes, manufactured and supplied according to DIN 28180 and ASTM A179.
Tubes for heat exchangers are made of steel according to:
Standard | Application |
---|---|
ASTM A179 | Seamless Cold-Drawn Low-Carbon Steel Heat-Exchanger and Condenser Tubes |
ASTM A192 | Seamless Carbon Steel Boiler Tubes for High-Pressure Service |
ASTM A210 | Seamless Medium-Carbon Steel Boiler and Superheater Tubes |
ASTM A213 | seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes |
ASTM A334 | Seamless Steel Pipe for Low-Temperature Service and other Applications with Required Notch Toughness |
JIS G3461/2 | carbon steel tubes used for heat exchange in boilers, heat exchangers, condensers, and similar equipment |
EN10216-1/2 | specified the standard of cold processed precision steel tubes in a wide range of sizes |
DIN17175 | seamless tubes for high-pressure and high-temperature applications, specifically for boilers and heat exchangers |
Standard | Grade | Chemical Components (%) | Mechanical Properties | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
C | Si | Mn | P | S | Mo | Cr | V | T.S. (Mpa) | Y.S. (Mpa) | E.L. (%) | Hardness (HRB) | ||
ASME SA179 | SA179 | 0.06-0.18 | / | 0.27-0.63 | ≤0.035 | ≤0.035 | / | / | / | ≥325 | ≥180 | ≥35 | ≤72 |
ASME SA192 | SA192 | 0.06-0.18 | ≤0.25 | 0.27-0.63 | ≤0.035 | ≤0.035 | / | / | / | ≥325 | ≥180 | ≥35 | ≤77 | ASME SA210 | A1 | ≤0.27 | ≥0.10 | ≤0.93 | ≤0.035 | ≤0.035 | / | / | / | ≥415 | ≥255 | ≥30 | ≤79 |
C | ≤0.35 | ≥0.10 | 0.29-1.06 | ≤0.035 | ≤0.035 | / | / | / | ≥485 | ≥275 | ≥30 | ≤89 | |
ASTM A333 /A334 | GR.1 | ≤0.30 | / | 0.4-1.06 | ≤0.025 | ≤0.025 | / | / | / | ≥380 | ≥205 | ≥35 | -45° |
GR.6 | ≤0.30 | ≥0.10 | 0.29-1.06 | ≤0.025 | ≤0.025 | / | / | / | ≥415 | ≥240 | ≥30 | -45° | |
GR.8 | ≤0.13 | 0.13-0.32 | ≤0.90 | ≤0.025 | ≤0.025 | / | / | 8.40-9.60 | ≥690 | ≥515 | ≥22 | -195° |
U bend tubes for heat exchangers applied mostly in oil and gas plants, chemical and petrochemical plants, refineries, power plants and renewable energy plants. Low fin tubes can be supplied in the form of U bends.
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.
Item | Condition (when) | Tolerance |
---|---|---|
Ovality | Nominal bend radius ≤ 2 x nominal OD | less than or equal to 12% |
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) |
We packs all U Tube bundles in bespoke wooden boxes and separate all U Tubes of different radii using finger pallets to facilitate easy assembly of bundles on receipt.
Any type of packing is available according to customer need to worldwide destinations.