How to get high quality pipe elbow?

What is a pipe elbow?

A pipe elbow is a type of piping that is bent at an angle or curve to allow straight pipes to be joined at an angle. The pipe elbow can be made from a variety of materials, from brass or cast iron to steel, alloy or plastic, and they are often threaded to allow other pipes to be joined to them. These corner fittings are often used in plumbing applications, but they can be used for other applications as well. The size and shape of the pipe elbow depends entirely on the user’s needs, and the materials used depend on the function of the piping unit.
Plumbing applications often necessitate the use of a pipe elbow. Since pipes do not always run straight, a pipe elbow may be necessary to allow water to flow around obstructions, through walls, or even to the outside of the house. The pipe elbow can come in different degrees of bend to allow for greater flexibility in piping options. In plumbing applications, the elbows are often joined to other piping pieces by screwing the pieces together with threads that are treated with plumber’s tape. This tape helps prevent leaks in the joints and also helps prevent the joints from loosening. Brass is a common choice of material for plumbing applications.
Other pipe elbow may be welded to the other pipes for a more permanent fixture. This is common when used on automobiles or heavy machinery. The elbows can be cut to length and then welded to straight pieces to form the desired shape. Exhaust systems on vehicles often require piping to run in between or around other parts of the car, so pipe elbows are used to accomplish the desired circuit. Stainless steel or other types of steel are common choices for automobile applications.
Elbows, also known as “ells,” are used to change the direction of a pipe system. An elbow typically features a 45, 90 or 180 degree bend, although other angles are also available. Elbows come in a variety of diameters and are generally threaded for connectivity. A common example of an elbow fitting in the home is the piece that extends from the wall of your shower to which the shower head connects.
Elbow are an English rock band consisting of Guy Garvey (lead vocals, guitar), Craig Potter (keyboard, piano, backing vocals), Mark Potter (guitar, backing vocals) and Pete Turner (bass guitar, backing vocals). They have played together since 1990, adopting the Elbow band name in 1997.
Wall thickness: SCH5 to SCH160
Size range: 1/2 to 56 inches (DN 15 to DN 1,400mm)
Degree: 22.5 Deg, 45 Deg, 90 Deg, 180 Deg
Manufacturing standards: ANSI, ISO, JIS and DIN
Process: butt welding, seamless
Type: Long radius, Short radius, Large size
Pressure: class 3000, 6000 and 9000
How to calculate a 90 degree elbow center?
If your elbow is a short radius it is 1 times your nominal pipe diameter. If it is a long radius it is 1 1/2 times your nominal pipe diameter.show me the exact pattern of long radius.
(90/2tan*Dia*1.5*25.4)
(45/2tan*Dia*1.5*25.4)
u will obtain Ur answer in (mm)
For 90 degree elbow(Dia*38.1) this formula used for only 90 degree elbow.
For 45 degree elbow(45/2of tan*Dia*1.5*25.4) this answer obtained in (mm).
How to distinguish between pipe elbow and pipe bend?
“All bends are elbows but all elbows are not bends.”
Infact, the pipe is bent to form an elbow.
Elbows are pre-fabricated and are firm in design.
There are issues with bends since the tickness at the bend radius reduces as we bend the pipe.
Bends typically have a minimum bending radius of 1.5 times pipe radius (R). If this bending radius is less than 1.5R, it is called Elbow. Reference to any international / industry standard need to be traced. 1.5, 3 and 4.5 R are the most common bending radii in industry.
Sharp bends are normally called Elbows.
An elbow is also typically a sharp 90 degrees and often is a separate piece.
A bend typically flows smoother since there are not irregular surfaces on the inside of the pipe, nor does the fluid have to change direction abruptly.
The most basic difference of them is the elbow relatively short than bend, R = 1D to 2 D is elbow More than 2D is bend. In the production process, cold bends can use Bending Machine to bend by ready-made straight bend. One-time completed also don’t need second corrosion. But elbow need manufacturers make to order, to do anti-corrosion, order cycle is long. Elbow price is higher than bend. But cost performance is much higher than bend. It is well-known that bend do not have anticorrosive processing is easy damaged, but the price is cheap so are  used very much in some demand which not very high engineering.
In the west-east gas transmission of course, cold bends cost is low. elbow need manufacturers make to order, needs corrosion, order cycle is long,but cold bends can use ready-made straight bend by Bending Machine to bend. One-time completed also don’t need second corrosion. The cold bend construction technology need follow oil standard .west-east gas transmission have the enterprise standard,but we can use either elbow nor bend in open area.

Types of pipe elbow

An elbow is a pipe fitting installed between two lengths of pipe or tubing to allow a change of direction, usually a 90° or 45° angle, though 22.5° elbows are also made. The ends may be machined for butt welding, threaded (usually female), or socketed, etc. When the two ends differ in size, the fitting is called a reducing elbow or reducer elbow.

 short radius 90degree - How to get high quality pipe elbow?
Short radius elbows
 long radius 90degree 1.5d - How to get high quality pipe elbow?
Long radius elbows
 stailness elbow - How to get high quality pipe elbow?
Stainless pipe elbows
larg diameter elbow - How to get high quality pipe elbow?
Big diameter elbows

The degree types of short radius pipe elbows as below:

An elbow is a pipe fitting installed between two lengths of pipe or tubing to allow a change of direction, usually a 180° or 90° angle, though 45° elbows are also made. The ends may be machined for butt welding (SW) or socketed welding(SW) etc.

Most elbows are available in short radius or long radius variants. When the two ends differ in size, the fitting is called a reducing elbow or reducer elbow.

Elbows are categorized based on various design features as below:

  • Long Radius (LR) Elbow is also called LR elbow – means the radius is 1.5 times the pipe diameter
    • L/R 45°Elbow: Long radius 45 degree elbow changes the direction by 45 degrees.
    • L/R 90°Elbow: Long radius 90 degree elbow changes the direction by 90 degrees.
    • L/R 180°Elbow: Long Radius 180 degree return bend allows complete reversal of flow.
  • Short Radius (SR) Elbow is also called SR elbow, – means the radius is 1.0 times the pipe diameter
    • Short radiu 45°Elbow: Short radius 45° elbow changes the direction by 45 degrees.
    • Short radius 90°Elbow: Short Radius 90° elbow is same as LR90 except for the measurement between end of elbow to center line is 1 x NPS.
    • Short radius 180° Elbow: Short Radius 180° return bend allows complete reversal of flow.

Elbows are categorized based on various design features as below:

  • Long Radius (LR) Elbows – radius is 1.5 times the pipe diameter
  • Short Radius (SR) Elbows – radius is 1.0 times the pipe diameter
  • 90 Degree Elbow – where change in direction required is 90°
  • 45 Degree Elbow – where change in direction required is 45°

A 90 degree elbow is also called a “90 bend” or “90 ell”. It is a fitting which is bent in such a way to produce 90 degree change in the direction of flow in the pipe. It used to change the direction in piping and is also sometimes called a “quarter bend”. A 90 degree elbow attaches readily to plastic, copper, cast iron, steel and lead. It can also attach to rubber with stainless steel clamps. It is available in many materials like silicone, rubber compounds, galvanized steel, etc. The main application of an elbow (90 degree) is to connect hoses to valves, water pressure pumps, and deck drains. These elbows can be made from tough nylon material or NPT thread.

Types of 90° elbows:
90° elbows are manufactured as SR (Short Radius) elbows and LR (Long Radius) elbows: 
SR (Short Radius) Elbows:
These elbows have a Center-to-Face dimension of 1.0 X diameter. They are typically used in tight areas where clearance is the main issue.
LR (Long Radius) Elbows:
These elbows have a Center-to-Face dimension of 1.5 X diameter. They are the most common type of elbow and used when space is available and flow is more critical.

90 degree Long Radius Elbow

long radius elbows 90 - How to get high quality pipe elbow?

The 90 degree Long Radius Elbow manufactured using superior grade raw materials. The 90 degree Long Radius Elbows are used for connecting pipes of different diameters and find wide applications in various chemicals, construction industries, paper, cement & ship builders.

We have adopted advanced production equipment to make our 90 degree Short Radius Elbow(1D D711.2~D1219.2), which can not only improve product quality, but also save raw materials.

ASME B16.9 Butt weld 90 degree Long Radius Elbow Dimensions

90 deg long redius dimen - How to get high quality pipe elbow?

ASME B16.9 90°Short Radius Elbow Dimensional Tolerance

NPS

O.D.
D

90 degrees
Long Radius
Center-to-End
A

45 degrees
Long Radius
Center-to-End
B

90 degrees
3D
Center-to-End
A

45 degrees
3D
Center-to-End
B

1/2

21.3

38

16

3/4

26.7

38

19

57

24

1

33.4

38

22

76

31

42.2

48

25

95

39

48.3

57

29

114

47

2

60.3

76

35

152

63

73

95

44

190

79

3

88.9

114

51

229

95

101.6

133

57

267

111

4

114.3

152

64

305

127

5

141.3

190

79

381

157

6

168.3

229

95

457

189

8

219.1

305

127

610

252

10

273

381

159

762

316

12

323.8

457

190

914

378

14

355.6

533

222

1067

441

16

406.4

610

254

1219

505

18

457

686

286

1372

568

20

508

762

318

1524

632

22

559

838

343

1676

694

24

610

914

381

1829

757

26

660

991

406

1981

821

28

711

1067

438

2134

883

30

762

1143

470

2286

964

32

813

1219

502

2438

1010

34

864

1295

533

2591

1073

36

914

1372

565

2743

1135

38

965

1448

600

2896

1200

40

1016

1524

632

3048

1264

42

1067

1600

660

3200

1326

44

1118

1676

695

3353

1389

46

1168

1753

727

3505

1453

48

1219

1829

759

3658

1516

ASME B16.9 90° Long Radius Elbow Dimensional Tolerance
DIMENSIONAL TOLERANCES – ELBOWS
For all fittings Elbows 90/45 deg 180° Returns
Nominal Pipe Size (NPS) Outside Ø 
at Bevel
Inside Ø 
at End
Wall Thickness 
t / t1
Center to End Dim. A-B-C-M Center to Center Dim.
O
Back to Face Dim.
K
Align- ment of Ends
U
1/2 a 2 1/2 1 0,8 Not 2 7 7 1
3 a 3 1/2 1 1,6 less 2 7 7 1
4 +2 -1 1,6 than 2 7 7 1
5 a 6 +3 -1 1,6 87,50% 2 7 7 1
8 2 1,6 of nominal 2 7 7 1
10 +4 -3 3,2 thickness 2 7 7 2
12 a 18 +4 -3 3,2 3 10 7 2
20 a 24 +6 -5 4,8 3 10 7 2
26 a 30 +7 -5 4,8 3 ….. ….. …..
32 a 48 +7 -5 4,8 5 ….. ….. …..

90 degree Short Radius Elbow

The 90 degree Short Radius Elbow manufactured using superior grade raw materials. The 90 degree Short Radius Elbows are used for connecting pipes of different diameters and find wide applications in various chemicals, construction industries, paper, cement & ship builders.

ASME B16.9 90 degree Short Radius Elbow Dimensional Tolerance

long radius elbows 90 - How to get high quality pipe elbow?90 deg short redius dimen - How to get high quality pipe elbow?

NPS O.D.
D
Center-to-End
A
1 33.4 25
42.2 32
48.3 38
2 60.3 51
73 64
3 88.9 76
101.6 89
4 114.3 102
5 141.3 127
6 168.3 152
8 219.1 203
10 273 254
12 323.8 305
14 355.6 356
16 406.4 406
18 457 457
20 508 508
22 559 559
24 610 610
ASME B16.9 90°Short Radius Elbow Dimensional Tolerance
Nominal Pipe Size 1/2 to 2½ 3 to  4 5 to 8 10 to 18 20 to 24 26 to 30 32 to 48
Outside Diameter
at Bevel (D)
+ 1.6
– 0.8
1.6 1.6 + 2.4
– 1.6
+ 4
– 3.2
+ 6.4
– 4.8
+ 6.4
– 4.8
+ 6.4
– 4.8
Inside Diameter at End 0.8 1.6 1.6 1.6 3.2 4.8 + 6.4
– 4.8
+ 6.4
– 4.8
Center-to-End (A) 2 2 2 2 2 2 3 5
Wall Thickness (t) Not less than 87.5% of Nominal Wall Thickness

A 45 degree elbow is also called a “45 bend” or “45 ell”. It is commonly used in water supply facilities, food industrial pipeline networks, chemical industrial pipeline networks, electronic industrial pipeline networks, air conditioning facility pipeline, agriculture and garden production transporting system, pipeline network for solar energy facility, etc.

45° Pipe Elbow 
45° Pipe Elbow is also known as “45 bends or 45 ells”. The 45° pipe elbow is used to connect tubes at a 45° pipe angle. As the name suggests, this is a pipe fitting device which is bent in such a way to produce 45° change in the direction of flow of the fluid/gas in the pipe.
 Like a 90° elbow, the 45° pipe elbow also attaches readily to pipes of various materials like plastic, copper, cast iron, steel, lead, rubber etc. They are typically made as LR (Long Radius) elbows. These types of elbows are available in various sizes (in mm or inches). They are available with different male to female BSP thread connections. Providing a wide choice of colors, these 45° elbows can be manufactured to meet different specifications, in terms of size and diameter.

45 degree Long Radius elbow

long radius elbows 45 - How to get high quality pipe elbow?

The 45 degree Long Radius Elbow manufactured using superior grade raw materials.

Butt weld 45 degree LOng Radius Elbow are used for connecting pipes of different diameters and find wide applications in various chemicals, construction industries, paper, cement & ship builders.

ASME B16.9 Butt weld 45 degree Long Radius Elbow Dimensions

45 deg long redius dimen - How to get high quality pipe elbow?

NPS

O.D.
D

90 degrees
Long Radius
Center-to-End
A

45 degrees
Long Radius
Center-to-End
B

90 degrees
3D
Center-to-End
A

45 degrees
3D
Center-to-End
B

1/2

21.3

38

16

3/4

26.7

38

19

57

24

1

33.4

38

22

76

31

42.2

48

25

95

39

48.3

57

29

114

47

2

60.3

76

35

152

63

73

95

44

190

79

3

88.9

114

51

229

95

101.6

133

57

267

111

4

114.3

152

64

305

127

5

141.3

190

79

381

157

6

168.3

229

95

457

189

8

219.1

305

127

610

252

10

273

381

159

762

316

12

323.8

457

190

914

378

14

355.6

533

222

1067

441

16

406.4

610

254

1219

505

18

457

686

286

1372

568

20

508

762

318

1524

632

22

559

838

343

1676

694

24

610

914

381

1829

757

26

660

991

406

1981

821

28

711

1067

438

2134

883

30

762

1143

470

2286

964

32

813

1219

502

2438

1010

34

864

1295

533

2591

1073

36

914

1372

565

2743

1135

38

965

1448

600

2896

1200

40

1016

1524

632

3048

1264

42

1067

1600

660

3200

1326

44

1118

1676

695

3353

1389

46

1168

1753

727

3505

1453

48

1219

1829

759

3658

1516

ASME B16.9 45° Long Radius Elbow Dimensional Tolerance
DIMENSIONAL TOLERANCES – ELBOWS
For all fittings Elbows 90/45 deg 180° Returns
Nominal Pipe Size (NPS) Outside Ø 
at Bevel
Inside Ø 
at End
Wall Thickness 
t / t1
Center to End Dim. A-B-C-M Center to Center Dim.
O
Back to Face Dim.
K
Align- ment of Ends
U
1/2 a 2 1/2 1 0,8 Not 2 7 7 1
3 a 3 1/2 1 1,6 less 2 7 7 1
4 +2 -1 1,6 than 2 7 7 1
5 a 6 +3 -1 1,6 87,50% 2 7 7 1
8 2 1,6 of nominal 2 7 7 1
10 +4 -3 3,2 tickness 2 7 7 2
12 a 18 +4 -3 3,2   3 10 7 2
20 a 24 +6 -5 4,8   3 10 7 2
26 a 30 +7 -5 4,8   3 ….. ….. …..
32 a 48 +7 -5 4,8   5 ….. ….. …..

The 180 degree Short radius Elbow manufactured using superior grade raw materials. The 180 degree Short radius Elbows are used for connecting pipes of different diameters and find wide applications in various chemicals, construction industries, paper, cement & ship builders.

45 degree SR elbow

The 45 degree Short Radius Elbow manufactured using superior grade raw materials. Butt weld 45 degree Short Radius Elbow are used for connecting pipes of different diameters and find wide applications in various chemicals, construction industries, paper, cement & ship builders.

ASME B16.9 Butt weld 45 degree Short Radius Elbow Dimensions

pipe fitting elbow 45degree - How to get high quality pipe elbow?45 deg short redius dimen - How to get high quality pipe elbow?

Nom. 
Pipe 
Size
Pipe 
Sched. 
or No.
Center- 
to-end 
Dimen.
Outside 
Dia.
Inside 
Dia.
Wall 
Thick.
Approx. 
Weight 
(lb.)
F OD ID T
     STANDARD WEIGHT
1/2 40 5/8 0.840 0.622 0.109 0.1
3/4 40 7/16 1.050 0.824 0.113 0.1
1 40 7/8 1.315 1.049 0.133 0.2
1 1/4 40 1 1.660 1.380 0.140 0.4
1 1/2 40 1 1/8 1.900 1.610 0.145 0.5
2 40 1 3/8 2.375 2.067 0.154 0.9
2 1/2 40 1 3/4 2.875 2.469 0.203 1.5
3 40 2 3.500 3.068 0.216 2.5
3 1/2 40 2 1/4 4.000 3.548 0.226 3.5
4 40 2 1/2 4.500 4.026 0.237 4.8
5 40 3 1/8 5.563 5.047 0.258 7.8
6 40 3 3/4 6.625 6.065 0.280 12
8 40 5 8.625 7.981 0.322 23
10 40 6 1/4 10.750 10.020 0.365 42
12 7 1/2 12.750 12.000 0.375 61
14 30 8 3/4 14.000 13.250 0.375 79
16 30 10 16.000 15.250 0.375 103
18 11 1/4 18.000 17.250 0.375 132
20 20 12 1/2 20.000 19.250 0.375 160
22 20 13 1/2 22.000 21.250 0.375 195
24 20 15 24.000 23.250 0.375 238
     EXTRA STRONG
Nom. 
Pipe 
Size
Pipe 
Sched. 
or No.
Center- 
to-end 
Dimen.
Outside 
Dia.
Inside 
Dia.
Wall 
Thick.
Approx. 
Weight 
(lb.)
F OD ID T
1/2 80 5/8 0.840 0.546 0.147 0.2
3/4 80 7/16 1.050 0.742 0.154 0.3
1 80 7/8 1.315 0.957 0.179 0.4
1 1/4 80 1 1.660 1.278 0.191 0.5
1 1/2 80 1 1/8 1.900 1.500 0.200 0.6
2 80 1 3/8 2.375 1.939 0.218 1.1
2 1/2 80 1 3/4 2.875 2.323 0.276 2.1
3 80 2 3.500 2.900 0.300 3.5
3 1/2 80 2 1/4 4.000 3.364 0.318 4.8
4 80 2 1/2 4.500 3.826 0.337 6.5
5 80 3 1/8 5.563 4.813 0.375 11
6 80 3 3/4 6.625 5.761 0.432 18
8 80 5 8.625 7.625 0.500 35
10 60 6 1/4 10.750 9.750 0.500 56
12 7 1/2 12.750 11.750 0.500 80
14 8 3/4 14.000 13.000 0.500 100
16 40 10 16.000 15.000 0.500 131
18 11 1/4 18.000 17.000 0.500 172
20 30 12 1/2 20.000 19.000 0.500 210
22 30 13 1/2 22.000 21.000 0.500 259
24 15 24.000 23.000 0.500 302
Ansi 16.9 tolerances – 45 Degree short radius elbow
DIMENSIONAL TOLERANCES – ELBOWS
For all fittings Elbows 90/45 deg 180° Returns
Nominal Pipe Size (NPS) Outside Ø 
at Bevel
Inside Ø 
at End
Wall Thickness 
t / t1
Center to End Dim. A-B-C-M Center to Center Dim.
O
Back to Face Dim.
K
Align- ment of Ends
U
1/2 a 2 1/2 1 0,8 Not 2 7 7 1
3 a 3 1/2 1 1,6 less 2 7 7 1
4 +2 -1 1,6 than 2 7 7 1
5 a 6 +3 -1 1,6 87,50% 2 7 7 1
8 2 1,6 of nominal 2 7 7 1
10 +4 -3 3,2 tickness 2 7 7 2
12 a 18 +4 -3 3,2   3 10 7 2
20 a 24 +6 -5 4,8 3 10 7 2
26 a 30 +7 -5 4,8 3 ….. ….. …..
32 a 48 +7 -5 4,8   5 ….. ….. …..

long radius elbows 180 - How to get high quality pipe elbow?

180 degree Short Radius Elbow

The 180 degree Short radius Elbow manufactured using superior grade raw materials. The 180 degree Short radius Elbows are used for connecting pipes of different diameters and find wide applications in various chemicals, construction industries, paper, cement & ship builders.

long radius elbows 180 - How to get high quality pipe elbow?
ASME B16.9 Butt weld 180 degree Short radius Elbow Dimensions

180 deg short redius dimen - How to get high quality pipe elbow?

ASME B16.9 180 degree Short radius Elbow Dimensional Tolerance
NPS O.D.
D
180° Short radius 180° Short Radius
Center to
Center
O
Back to
Face
K
Center to
Center
O
Back to
Face
K
1/2 21.3 76 48
3/4 26.7 76 51
1 33.4 76 56 51 41
42.2 95 70 64 52
48.3 114 83 76 62
2 60.3 152 106 102 81
73 190 132 127 100
3 88.9 229 159 152 121
101.6 267 184 178 140
4 114.3 305 210 203 159
5 141.3 381 262 254 197
6 168.3 457 313 305 237
8 219.1 610 414 406 313
10 273 762 518 508 391
12 323.8 914 619 610 467
14 355.6 1067 711 711 533
16 406.4 1219 813 813 610
18 457 1372 914 914 686
20 508 1524 1016 1016 762
22 559 1676 1118 1118 838
24 610 1829 1219 1219 914
ASME B16.9 180° Short Radius Elbow Dimensional Tolerance
For all fittings 180° Returns
Nominal Pipe Size (NPS) Outside Ø 
at Bevel
Inside Ø
at End
Wall Thickness 
t / t1
Center to Center Dim.
O
Back to Face Dim.
K
Align- ment of Ends
U
1/2 a 2 1/2 1 0,8 Not 7 7 1
3 a 3 1/2 1 1,6 less 7 7 1
4 +2 -1 1,6 than 7 7 1
5 a 6 +3 -1 1,6 87,50% 7 7 1
8 2 1,6 of nominal 7 7 1
10 +4 -3 3,2 thickness 7 7 2
12 a 18 +4 -3 3,2 10 7 2
20 a 24 +6 -5 4,8 10 7 2
26 a 30 +7 -5 4,8 ….. ….. …..
32 a 48 +7 -5 4,8 ….. ….. …..

180 degree Long Radius Elbow

long radius elbows 180 - How to get high quality pipe elbow?

The 180 degree Long Radius Elbow manufactured using superior grade raw materials.

The 180 degree Long Radius Elbows are used for connecting pipes of different diameters and find wide applications in various chemicals, construction industries, paper, cement & ship builders.

We have adopted advanced production equipment to make our 180 degree Long Radius Elbow(1D D711.2~D1219.2), which can not only improve product quality, but also save raw materials.

ASME B16.9 Butt weld 180 degree Long Radius Elbow Dimensions

180 deg long redius dimen - How to get high quality pipe elbow?

NPS O.D. D 180° Long Radius
Center to Center
O
Back to Face
K
1/2 21.3 76 48
3/4 26.7 76 51
1 33.4 76 56
42.2 95 70
48.3 114 83
2 60.3 152 106
73 190 132
3 88.9 229 159
101.6 267 184
4 114.3 305 210
5 141.3 381 262
6 168.3 457 313
8 219.1 610 414
10 273 762 518
12 323.8 914 619
14 355.6 1067 711
16 406.4 1219 813
18 457 1372 914
20 508 1524 1016
22 559 1676 1118
24 610 1829 1219
ASME B16.9 180° Long Radius Elbow Dimensional Tolerance
For all fittings 180° Returns
Nominal Pipe Size (NPS) Outside Ø 
at Bevel
Inside Ø
at End
Wall Thickness 
t / t1
Center to Center Dim.
O
Back to Face Dim.
K
Align- ment of Ends
U
1/2 a 2 1/2 1 0,8 Not 7 7 1
3 a 3 1/2 1 1,6 less 7 7 1
4 +2 -1 1,6 than 7 7 1
5 a 6 +3 -1 1,6 87,50% 7 7 1
8 2 1,6 of nominal 7 7 1
10 +4 -3 3,2 thickness 7 7 2
12 a 18 +4 -3 3,2 10 7 2
20 a 24 +6 -5 4,8 10 7 2
26 a 30 +7 -5 4,8 ….. ….. …..
32 a 48 +7 -5 4,8 ….. ….. …..

Most elbows are available in short radius or long radius variants.

SHORT RADIUS ELBOWS

The short radius elbows have a center-to-end distance equal to the Nominal Pipe Size (NPS) in inches, while the long radius is 1.5 times the NPS in inches. Short elbows are widely available, and are typically used in pressurized systems.

LONG RADIUS ELBOWS

Long elbows are typically used in low-pressure gravity-fed systems and other applications where low turbulence and minimum deposition of entrained solids are of concern.

Forged Pipe Elbow

45-Degree and 90-Degree Elbow Fittings with SW& Threaded Connection Ends. 
Pressure: 2000LBS, 3000LBS, 6000LBS, 9000LBS

Size: from 1/8″ to 4″

Material: ASTM A105, F304, F316, F304L, F316L, A182 F11/F22/F91

Connection ends: socket weld and threaded

Threaded Pipe Fitting SS304 Precision Cast Fittings

threaded pipe fitting - How to get high quality pipe elbow?Threaded Pipe Fitting SS304 with 90 degrees Elbow, Class 150lb, Male and Female Thread.

Size: 1/2 to 4 inchesb

304 90 degrees elbow, class 150lb, with male and female thread

Materials: SS304 and SS316

Manufacturing standards: ANSI, JIS, and DIN

Our prefessional foundry can do sand casting,lost wax casting and die casting .

forged elbows - How to get high quality pipe elbow?

The material as bellowing: 
Gray Iron, Ductile Iron, Steel, Stainless Steel, Malleable Iron and Alloy 
The products is widely used in automobile , machinery, pipe fittings, pump parts, valve part and other industry.

We are a group company consisting of:

  • 4 Sand Casting Plants (mainly produce Cast Iron and Ductile Iron Products)
  • 2 Resin Sand Casting Plants (mainly produce Cast Steel&Cast Iron Products)
  • 3 Investment Casting Plants (mainly produce Stainless Steel and Carbon Steel products)
Thick-walled seamless cast iron pipe

Size: O.D.219-680mm, W.T.:40-90mm

Mateiral:10#, 20#, 35#, 45#, 16Mn, 27Simn etc.

Design of Pipe Elbow

An elbow provides a change in material-flow direction. This adds pressure losses to the system due to impact, friction and re-acceleration.
As product enters the inlet of the elbow, it typically continues moving straight ahead to the first (or primary) impact zone. The product is then deflected at an angle toward the outlet of the elbow. The deflection angle is determined by the elbow design, the product’s characteristics, the conveying velocity, and specific load (also called the product-to-gas ratio). In many designs, the product will hit one or more secondary impact zones before exiting the elbow.
Impact forces can cause severe degradation of fragile or breakage-sensitive products, generating a large amount of fines or dust and creating quality issues. Heat-sensitive products, such as plastic pellets, can overheat on the contact surface this can result in unwanted tails or streamers on the pellet or film build-up on the surface of the elbow, which can eventually lead to product contamination. Abrasive products can cause wear, leading to work-out elbows and system leaks and causing maintenance and safety issues.

Elbows can change direction to any angle as per requirement. An elbow angle can be defined as the angle by which the flow direction deviates from its original flowing direction (See Fig.1 below).Even though An elbow angle can be anything greater than 0 but less or equal to 90°But still a change in direction greater than 90° at a single point is not desirable. Normally, a 45° and a 90° elbow combinedly used while making piping layouts for such situations.

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Fig.1 A typical elbow with elbow angle (phi)

Elbow angle can be easily calculated using simple geometrical technique of mathematics. Lets give an example for you. Refer to Fig.2. Pipe direction is changing at point A with the help of an elbow and again the direction is changing at the point G using another elbow.

Untitled 1 - How to get high quality pipe elbow?
Fig.2 Example figure for elbow angle calculation
In order to find out the elbow angle at A, it is necessary to consider a plane which contains the arms of the elbow. If there had been no change in direction at point A, the pipe would have moved along line AD but pipe is moving along line AG. Plane AFGD contains lines AD and AG and elbow angle (phi) is marked which denotes the angle by which the flow is deviating from its original direction.
Considering right angle triangle AGD, tan(phi) = √( x2 + z2)/y
Similarly elbow angle at G is given by : tan (phi1)=√ (y2 +z2)/x
Elbow Radius:
Elbows or bends are available in various radii for a smooth change in direction which are expressed in terms of pipe nominal size expressed in inches. Elbows or bends are available in three radii,
a. Long radius elbows (Radius = 1.5D): used most frequently where there is a need to keep the frictional fluid pressure loss down to a minimum, there is ample space and volume to allow for a wider turn and generate less pressure drop.
b. Long radius elbows (Radius > 1.5D): Used sometimes for specific applications for transporting high viscous fluids likes slurry, low polymer etc. For radius more than 1.5D pipe bends are usually used and these can be made to any radius.However, 3D & 5D pipe bends are most commonly used
b. Short radius elbows (Radius = 1.0D): to be used only in locations where space does not permit use of long radies elbow and there is a need to reduce the cost of elbows. In jacketed piping the short radius elbow is used for the core pipe.
Here D is nominal pipe size in inches.
There are three major parameters which dictates the radius selection for elbow. Space availability, cost and pressure drop.
Pipe bends are preferred where pressure drop is of a major consideration.
Use of short radius elbows should be avoided as far as possible due to abrupt change in direction causing high pressure drop.
Minimum thickness requirement:
Whether an elbow or bend is used the minimum thickness requirement from code must be met. Code ASME B 31.3 provides equation for calculating minimum thickness required (t) in finished form for a given internal design pressure (P) as shown below:
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Fig.3: Code equation for minimum thickness requirement calculation
Here,
R1 = bend radius of welding elbow or pipe bend
D = outside diameter of pipe
W = weld joint strength reduction factor
Y = coefficient from Code Table 304.1.1
S = stress value for material from Table A-1 at maximum temperature
E = quality factor from Table A-1A or A-1B
Add any corrosion, erosion, mechanical allowances with this calculated value to get the thickness required.

End Connections:
For connecting elbow/bend to pipe the following type of end connections are available

  • Butt welded: Used alongwith large bore (>=2 inch) piping
  • Socket welded: Used alongwith pipe size
  • Screwed:
  • Flanged:
Butt welded Elbows:
  • Pipe is connected to butt welded elbow as shown in Fig. 4 by having a butt-welding joint.
  • Butt welded fittings are supplied with bevel ends suitable for welding to pipe. It is important to indicate the connected pipe thickness /schedule while ordering. All edge preparations for butt welding should conform to ASME B16.25.
  • Dimensions of butt welded elbows are as per ASME B16.9. This standard is applicable for carbon steel & alloy steel butt weld fittings of NPS 1/2” through 48”.
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Fig.4: A typical Butt-Welded Elbow
  • Dimensions of stainless steel butt welded fittings are as per MSS-SP-43. Physical dimensions for fittings are identical under ASME B16.9 and MSS-SP-43. It is implied that the scope of ASME B16.9 deals primarily with the wall thicknesses which are common to carbon and low alloy steel piping, whereas MSS-SP-43 deals specifically with schedule 5S & 10S in stainless steel piping.
  • Dimensions for short radius elbows are as per ASME B16.28 in case of carbon steel & low alloy steel and MSS-SP-59 for stainless steel.
  • Butt welded fittings are usually used for sizes 2” & above. However, for smaller sizes up to 1-1/2” on critical lines where use of socket welded joints is prohibited, pipe bends are normally used. These bends are usually of 5D radius and made at site by cold bending of pipe. Alternatively, butt welded elbows can be used in lieu of pipe bends but usually smaller dia lines are field routed and it is not possible to have the requirement known at initial stage of the project for procurement purpose. So pipe bends are preferred. However, pipe bends do occupy more space and particularly in pharmaceutical plants where major portion of piping is of small dia. and layout is congested, butt welded elbows are preferred.
  • Butt welded joints can be radiographed and hence preferred for all critical services.
  • Material standards as applicable to butt welded fittings are as follows:
ASTM A234:

This specification covers wrought carbon steel & alloy steel fittings of seamless and welded construction. Unless seamless or welded construction is specified in order, either may be furnished at the option of the supplier. All welded construction fittings as per this standard are supplied with 100% radiography. Under ASTM A234, several grades are available depending upon chemical composition. Selection would depend upon pipe material connected to these fittings.
Some of the grades available under this specification and corresponding connected pipe material specification are listed below:
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ASTM A403:
This specification covers two general classes, WP & CR, of wrought austenitic stainless steel fittings of seamless and welded construction.
Class WP fittings are manufactured to the requirements of ASME B16.9 & ASME B16.28 and are subdivided into three subclasses as follows:
WP – SManufactured from seamless product by a seamless method of manufacture.
WP – W These fittings contain welds and all welds made by the fitting manufacturer including starting pipe weld if the pipe was welded with the addition of filler material are radiographed. However no radiography is done for the starting pipe weld if the pipe was welded without the addition of filler material.
WP-WX These fittings contain welds and all welds whether made by the fitting manufacturer or by the starting material manufacturer are radiographed.
Class CR fittings are manufactured to the requirements of MSS-SP-43 and do not require non-destructive examination.
Under ASTM A403 several grades are available depending upon chemical composition. Selection would depend upon pipe material connected to these fittings. Some of the grades available under this specification and corresponding connected pipe material specification are listed below:
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ASTM A420:
  • This specification covers wrought carbon steel and alloy steel fittings of seamless & welded construction intended for use at low temperatures. It covers four grades WPL6, WPL9, WPL3 & WPL8 depending upon chemical composition. Fittings WPL6 are impact tested at temp – 50° C, WPL9 at -75° C, WPL3 at -100° C and WPL8 at -195° C temperature.
  • The allowable pressure ratings for fittings may be calculated as for straight seamless pipe in accordance with the rules established in the applicable section of ASME B31.3.
  • The pipe wall thickness and material type shall be that with which the fittings have been ordered to be used, their identity on the fittings is in lieu of pressure rating markings.

Manufacturing process of the pipe elbow

Mandrel method (Hot Forming)

  • One of the most common Pipe Fittings Manufacturing Process for manufacturing Elbows Or Pipe Bends from the pipe is mandrel method which is kind of hot forming methods.
  • In this method, the pipe is cut in pieces and push with the help of hydraulic ram. It is pushed over a die called “mandrel” which allows the pipe to expand and bend simultaneously.
  • This method can be used to manufacture a wide range of the diameter of elbows or pipe bends
  • 20180104100126 45592 - How to get high quality pipe elbow?
  • ELBOWS Or Pipe Bends Mandrel method

Extrusion Method

In cold Extrusion method, a pipe with the same diameter as finished product is pushed through a die and formed into its desired shape. Usually applied to stainless steel small to medium sizes elbows or pipe bends.

20180104100215 30422 - How to get high quality pipe elbow?

Extrusion Method

UO Method

UO method is used to manufacture medium size of the elbow, tee, and reducers. The plate is cut out into a specially designed shape, it is formed first into a U-shape using a die and then into an O-shape or tubular form using another die, that is why this method is known as UO method. Once the fittings formed in tumbler shaped it is welded from inside and outside of the closing seam. A cut plate is 1st from in U shape and then in O shape.

20180104100303 36471 - How to get high quality pipe elbow?

UO Method

Hot Forming Method

In a Hot Forming Die Bending method, a Pipe is heated to forming temperature & formed in the die with the specific shape, this process may be repeated as needed to obtain the required shape, size and wall thickness. Usually applied to thick-wall items that cannot be bent on a mandrel die.

20180104100406 54259 - How to get high quality pipe elbow?

Hot Forming method for Elbow Manufacturing

Materials
  • Carbon steel: ASTM/ASME A234 WPB-WPC
  • Alloy steel: –WP 22-WP 5-WP 91-WP 911
    • ASTM A335 P22
    • ASME SA335 P91 elbow
    • ASTM A234 WP 11
  • Low temperature steel: ASTM/ASME A402 WPL 3-WPL 6
  • High performance steel: ASTM/ASME A860 WPHY 42-46-52-60-65-70
  • Stainless steel: ASTM/ASME A403 WP 304-304L-304H-304LN-304N
    • ASTM/ASME A403 WP 316-316L-316H-316LN-316N-316Ti
    • ASTM/ASME A403 WP 321-321H ASTM/ASME A403 WP 347-347H
Standards
  • GB/T12459-2005 GB/T13401-2005 GB/T10752-2005 SH/T3408-1996 SH/T3409-1996
  • SY/T0609-2006 SY/T0518-2002 SY/T0510-1998
  • DL/T695-1999 GD2000 GD87-1101
  • HG/T21635-1987 HG/T21631-1990
  • ASME B16.9-2007 ASME B16.25-2007
  • MSS SP 75-2008 MSS SP 43-2008
  • CSA Z245.11-05-2005
  • EN10253-1-1999 EN10253-2-2007 EN10253-3-2008 EN10253-4-2008
  • DIN2605-1-1992 DIN2605-2-1995
  • BS1640-1-1962 BS1640-2-1962 BS1640-3-1968 BS1640-4-1968 BS1965-1-1963
  • AFNOR NF A 49-289-1990 AFNOR NF A 49-170-1-1999 AFNOR NF A 49-170-2-2009 AFNOR NF A 49-170-3-2009
  • AFNOR NF A 49-170-4-2009 ISO3419-1981 ISO5251-1981
  • JIS B2311-2009 JIS B2312-2009 JIS B2313-2009
  • ASME B16.9 Butt weld 45 degree Long Radius Elbow Dimensions

Applications of pipe elbows:
Various applications of pipe elbows are as follows:

  • They are manufactured to be used in flow lines for gases, fluids in industrial processes, medical, construction and many other specialized applications.
  • The elbows are constructed of heavy materials for rigid applications like extreme high/low temperature resistance etc.
  • The elbows are specifically designed for use on process and control systems, instrumentation, and equipment used in chemical, petroleum, fluid power, electronic and pulp and paper plants. 

The stainless steel elbow on amazon is very expensive

Source: China Pipe Elbow Manufacturer – Yaang Pipe Industry Co., Limited (www.ugsteelmill.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

If you want to have more information about the article or you want to share your opinion with us, contact us at sales@ugsteelmill.com

Please notice that you might be interested in the other technical articles we’ve published:

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  • How to test pipe fitting?

  • Manufacturing process of cold rolled steel pipe

  • Development trend of high pressure pipe fittings

  • How to get high quality flanges

  • How to get high quality pipe fittings

  • How to get high quality bellow expansion joints

  • How to get high quality alloy steel pipes

  • HOW TO GET HIGH QUALITY STEEL PIPES

  • WHAT IS THE DIFFERENCE BETWEEN LATERAL TEE AND TRUE WYE

  • WHAT ARE OUTLET PIPE FITTINGS

  • What are pipe caps

  • WHEN TO USE A SPECTACLE BLIND FLANGE

  • HOW TO GET HIGH QUALITY BOILER TUBES

  • How to get high quality pipe bend

  • What are pipe caps

  • How to Calculate a Pipe Bend

  • Stainless steel pipe bend

  • The production process of stainless steel pipe bend

  • Difference Between A Pipe Elbow And A Pipe Bend

  • What is a pipe elbow

  • How To Distinguish Inferior Steel Pipe

  • How to get high quality pipe cap

References:

  • https://en.wikipedia.org/wiki/Elbow_(band)
  • https://www.yaang.com/what-are-pipe-elbows.html
  • https://hardhatengineer.com/pipe-fittings/pipe-fittings-manufacturing-process/
  • http://www.whatispiping.com/piping-elbows-and-bends
  • https://www.yaang.com

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