SA213 T9 U bend tubes for heat exchanger

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U bend dimension capablity

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

Dimensional controls on U bend tube

‘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.

Heat Treatment

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

Heat Treatment Equipment

• Heat treatment equipment is computer controlled with the added facility of data recording.
• An argon protective atmopshere is used inside stainless and special alloy tubes during heat treatment.
• We can provide all types of annealing; solution annealing and stress relieving.

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

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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)

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.

Dimension control on U bend tubes

• Ovality of straight and bending tube parts
• Thinning of straight and bending tube parts
• Leg spacing length
• U bend tube length (leg + radius + (0,5 x OD))
• Difference between legs length
• Straightness of legs
• Deviation from bend plane
• Twist of bending portion
• Squareness and cleanliness of tube ends
• Complete visual control

Heat treatment of U bend tubes

Post bending heat treatment by electrical resistance (Joule effect) is applied. The temperature is monitored and controlled during the process. It is possible to perform the heat treatment in a nitrogen atmosphere.

U bend tubes can be tested as follows

• Hydrostatic Test
• Air Underwater Test
• Pulsating Pressure Test
• Dye Penetrant Test
• Magnetoscopic test

Sizes tolerances of U bend tubes are to fulfil the requirements of: ASTM A556 / 556M and DIN 28 179

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“U bend tubes for heat exchangers applied mostly in Oil & Gas plants, Chemical & Petrochemical plants, Refineries, Power plants, Renewable energy plants.”

Note:
We produced condenser tube, carbon steel by the material out into the condenser tube, stainless steel condenser tube and carbon steel and stainless steel tubular mixed condensation out of three, according to the form of fixed tube plate, floating head type, U-tube heat exchanger, according to the structure into a single tube, twin-tube and multi-way tube, heat transfer area of 1 ~ 500m2, can be customized according to user needs.

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Surface condition Finished U Bend Tube shall be free of scale, without scratches after bending

Dimensional tolerances U Bend Tube acc. to TEMA R.C.B. and ASTM A566, ASTM A688

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:

• tf wall thickness after bending, in. [mm],
• T specified minimum tube wall thickness, in. [mm],
• R centerline bend radius, in. [mm], and
• D nominal outside tube diameter, in. [mm].

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:

• Connections that come in standardized sizes for easy assembly and feature additional thread and surface protection for clean installation
• U-bend tubes expanded into a tubesheet which allow for tube expansions and contractions due to thermal fluctuations.
• Gaskets that are made of high quality compressed fibres which lends to reusability.
• A standard cast-iron or steel head for heavy duty services (also available as a spare part).
• Saddle attaches which make for quick and easy mounting.
• Punched baffles with minimal clearances between tubes guaranteeing correct fluid flow and minimized bypass
• A welded shell protected with high quality paint for corrosion resistance.
• Copper steel tubes which allow for strong, durable performance over a wide range of applications. Unique tube bundle layout (chevron corrugated pattern) minimizes deposit buildup at the edges and optimises media flow for high velocity flow turbulence.

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ASTM A179 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-bent tube sizes (u-bending, u-bend)

Tube Outside Diameter	Tube Wall Thickness	Bending Radius	U Tube Straight “Leg” Length	Straight Tube Before U Bending
min. 12,70 mm	min. 0,70 mm	min. 1,5 x D	max. 11 000 mm	max. 24 000 mm
max. 31,75 mm	max 5,16 mm	max. 1 250 mm

Sizes tolerances of U bend tubes are to fullfil the requirements of: ASTM A556 / 556M and DIN 28179

Heat treatment of U bent tubes

Post bending heat treatment by electrical resistance (Joule effect) is applied. The temperature is monitored and controlled during the process. It is possible to perform the heat treatment in a nitrogen atmosphere.

U bent tubes can be tested as follows

All materials are hydro-tested as standard. Stress relieving is carried out in a gas-fired furnace or solution annealed using an induction heat process. We can offer a range of additional testing on request, including dye penetrant and PMI testing.

Bending Type:

Cold Bending and Hot Bending.

Heat Treatment:

After Cold Bending, the bending area needs heat treatment.

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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.

ASME SA556 Chemical Compostion

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

ASME SA556 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

JIS Number and Corrensponding Foreign Standards

JIS

ASTM

BS

DIN

NF

ISO

Index Number

Standard Number

Grade

Tupe

Standard Number

Grade

Tupe

Standard Number

Grade

Tupe

Standard Number

Grade

Tupe

Standard Number

Grade

Tupe

Standard Number

Grade

Tupe

G3461

STB340

C

A161

LC

C

3059

HFS320

C

A49-245

TS34e

C

C010

(STB35)

A192

–

C

"

CFS320

C

"

TS34c

C

A226

–

C

"

ERW320

C

A556

GrA2

C

"

CEW320

C

A557

GrA2

C

"

S1 360

C

"

S2 360

C

"

ERW 360

C

"

CEW360

C

3606

ERW320

C

"

CEW320

C

"

CFS320

C

STB410

C

A179

GrC

C

3059

S1 440

C

17175

St45.8

C

A49-213

TU42c

C

2604/2

TS9H

C

(STB42)

A210

GrA1

C

"

S2 440

C

17177

St42.8

C

A49-215

TU42c

C

"

TW9H

C

A556

GrB2

C

"

ERW 440

C

A49-243

TS42c

A557

GrB2

C

"

CEW 440

C

A49-245

TS42c

3602

HFS 410

C

"

TS42c

"

CFS 410

C

"

ERW 410

C

"

CEW 410

C

3606

ERW 440

C

"

CEW 440

C

"

CFS 440

C

STB510

C

C

17175

19Mn5

C

A49-213

TU52C

C

2604/2

TS18

C

(STB52)

C

A49-248

TU52C

C

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.

Any type of packing is available according to customer need to worldwide destinations.

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• For roadfreight 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 packings lists are attached to wooden cases to give quick and clear identification of contents.

ASTM A213 ASME SA213 Seamless Alloy Carbon Steel Heat Exchanger U Tubes for Boilers

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With strong wood structure box packing by containers loading and shipping.

Hydraulic tubes, Hydraulic pipeline, cylinders Pneumatic cylinders, U tube