Resources

On this page we hope to provide common terminology, bending forms and additional information that you may find useful in helping describe your product to us.   If you have any additional questions please feel free to contact us.

Common Bending Terms

Arc – The degree of bend for the curved portion of an pipe, tube or beam.

Bevel – A type of end finishing for a pipe, tube or beam.

Centerline Radius (CR) – Distance from the center of curve to the centerline axis of the pipe, tube or beam. Abbreviated as CLR.

Cold Bending – Using cold shaping methods to bend a pipe or other object.

Degree – An increment of angle to form a bend above the plane of 0 degrees, to which the bend is formed (i.e. 10, degrees, 45 degrees, 90 degrees, 180 degrees, etc.) See Diagram

Easy Way (EZ) – Bending of a rectangular pipe, tube or beam along its shortest dimension of length.

Hard Way (HW) – Bending of a rectangular pipe, tube or beam along its thickest dimension of length.

I.D. – The Inside diameter of the pipe or tube.

Neutral Axis – The unbent portion of an object (pipe, tube or beam) that is neither compressed or under tension due to bend.

O.D. – The Outside diameter of a pipe, tube or beam in inches.

Out of Plane – The deviation from a horizontal plane of rectangular object by a single bend, between its tangent points and the centerline of the bend.

Ovality – The distortion of pipe or tube from it’s a circular shape caused by bending.

Material Grade – Manufacturers’ specification of material for pipe, tube or beam material, (i.e. A53B, T304W SS).

Plain End – Square cuts made to a pipe, tube or beam prior to bending.

Roll Past – Degree or fraction of degree that a pipe, tube or beam is bent beyond a specified point.

Rough Cut – Pipe, tube or beam end cuts that are not required to be straight.

Square Cut – End cuts to a pipe, tube or beam that are square to the centerline of a bend after the bending process.

Tangent – The straight portion of material on either side of arc of a bend.

Tangent Point – A point where the bend of a pipe, tube or beam begins or ends.

Taper Bore – A milling or grinding out of the inside diameter of the end of a bend to create a tapered pipe or tube diameter.

Wall – The thickness in inches of the outside wall of a pipe or tube.

Wrinkles – Ribbed or wavy indentations in the inner bend angle of a bend of a pipe, tube or beam.

terminology 1

90 degree bend

a – First straight
b – Second straight
d – pipe or tube diameter
L – Length of Bend
H – Height of Bend
A – Degree of Bend
W – Material wall thickness
w – Width of bend
CR Centerline Radius

offset bend reference

a = First straight
b = First bend
c – Mid-straight
d – Second bend
e – Last straight
O – Height of offset
L – Length of offset
R1 – First radius
R2 – Second radius
W – Tube wall thickness
D – Tube outside diameter

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Design Procedure for Bent Tubular Products

1.Research material available and bendability to determine design feasibility. Use bend radii of (2-D) 2 x O.D. of tube or greater when design permits. Always use existing tooling if possible to avoid expensive die costs.

2.When possible, always avoid bends too close together or bends within bends. This type of design requires special tooling and will greatly increase piece part costs.

3.Make all bend radii on tube being designed same radii to minimize production costs. Allow minimum of 2 X tube diameter between bends for clamping. Check with BOYCE for clamp length information.

4.Avoid expanded and reduced ends too close to bend tangent. Allow 1″ minimum on expanded or reduced ends and 4″ for flare, bead or end finishing.

5.Bend radii smaller than (2-D) 2 X tube diameter will result in specialized tooling and material. Always use the largest radius possible when designing bent parts to avoid premium bends. All rounds are designed on a centerline radius, squares and rectangles on an inside radius.

6.Bend tolerances on single bend parts are +/- 1º. On multiple bend parts +/- 1-1/2º and +/- 3/32 c-c up to 2-1/2″ and +/- 2º of bend +/- 3/16″ above 2-1/2″. Tube cutting tolerance +/- 3/32″ unless otherwise specified on part print, our quotations are based on these tolerances. Try to avoid machine tolerances and true radius dimensions on bend drawing specifications.

procedure reference

Common Bending Shapes

cold bend sketch

Specifications

Maximum Allowable Working Pressures for common boiler tube sizes, SA178A or SA192, where expanded into drums or headers. From ASME Boiler & Pressure Vessel Code, Section I, Table PWT-10. This information is copyrighted by ASME, and is reproduced with permission. This table is presented for information only, and is not a substitute for proper ASME design procedures.
Tube Outside Diameter, inches
Thck., inches. BWG No. 1.250 1.500 1.750 2.000 2.250 2.500 2.750 3.000 3.250
0.065 16 350                
0.075 15+ 550 430              
0.085 14+ 740 590 490 410          
0.095 13 1760 760 630 530 460 400 350    
0.105 12- 1980 1600 1340 1150 570 500 440 390  
0.120 11   1870 1570 1340 1170 1040 930 840 460
0.135 10+     1790 1540 1340 1190 1060 960 880
0.150 9+     2020 1740 1520 1340 1200 1090 990
0.165 8       1940 1690 1500 1340 1210 1100
0.180 7         1870 1660 1480 1340 1220
0.200 6-           1870 1670 1520 1380
0.220 5             1870 1690 1540
0.240 4+               1870 1700
0.260 3+                 1870
0.280 2-                 2040
Common Boiler Tube Specifications 
 
 

ASME Spec. ASME Grade ERW or Smls. Description Typical uses
SA-178 A ERW Low carbon steel – C=0.18 max. Boiler tubes, economizers, low temp. superheaters
SA-178 C ERW Medium carbon steel – C=0.35 max. Boiler tubes, economizers, low temp. superheaters
SA-178 D ERW Carbon-manganese steel – C=0.27 max Not in common use
SA-192   Smls. Low carbon steel – C=0.18 max Waterwalls, economizers, low temp. superheaters
SA-210 A1 Smls. Medium carbon steel – C=0.27 max. Waterwalls, economizers, superheaters
SA-210 C Smls. Medium carbon steel – C=0.35 max. Waterwalls, economizers, superheaters
SA-209 T1 Smls. Low alloy steel – low carbon, 1/2% moly Superheaters
SA-209 T1a Smls. Low alloy steel – medium carbon, 1/2% moly Superheaters
SA-209 T1b Smls. Low alloy steel – low carbon, 1/2% moly Superheaters
SA-213 T2 Smls. Intermediate alloy – 1/2% chrome, 1/2% moly Waterwalls, superheaters, not in common use
SA-213 T11 Smls. Intermediate alloy – 1 1/4% chrome, 1/2% moly Waterwalls, superheaters
SA-213 T22 Smls. Intermediate alloy – 2 1/4% chrome, 1% moly Waterwalls, superheaters
SA-213 T5 Smls. Intermediate alloy – 5% chrome, 1/2% moly High temperature superheaters, not in common use
SA-213 T9 Smls. Intermediate alloy – 9% chrome, 1% moly High temperature superheaters, no longer in common use
SA-213 T91 Smls. Intermediate alloy – 9% chrome, 1% moly, 1/4% vanadium High temperature superheaters – the latest and greatest
SA-213 Tp-304 Smls. Stainless steel – 18% chrome, 8% nickel Superheaters
SA-213 Tp-304H Smls. Stainless steel for high temperature service High temperature superheaters
SA-213 Tp-316 Smls. Stainless steel – 16% chrome, 11% nickel Superheaters
SA-213 Tp-316H Smls. Stainless steel for high temperature service High temperature superheaters
SA-213 Tp-321 Smls. Stainless steel – 17% chrome, 9% nickel, 0.60% titanium Superheaters
SA-213 Tp-321H Smls. Stainless steel for high temperature service High temperature superheaters
SA-213 Tp-347 Smls. Stainless steel – 17% chrome, 9% nickel, columbium + tantalum=1.00% max. Superheaters
SA-213 Tp-347H Smls. Stainless steel for high temperature service High temperature superheaters
For boiler tubes, A-178A is the most common, and most economical choice.
Economizers are usually made from SA-178A or SA-210-A1.
 
Superheater materials vary widely, with SA-178A and SA-192 used most often in the lower temperature ranges. SA-210-A1, SA-213-T11, and SA-213-T22 are commonly seen in the intermediate temperature ranges, with the stainless grades, most frequently Tp-304H and Tp-347H, reserved for the higher temperature superheaters, although SA-213-T91 is increasingly specified for the highest temperatures.
Standard Pipe Dimensions and Weights
Use this table to find dimensions and weights for standard steel, alloy, and stainless steel pipe. Many additional diameters and schedules are available – only the more common ones are shown here.
 

Pipe Size Outside Dia. – Inches I. P. S. Schedule Avg. Wall – Inches Inside Dia. – Inches Wt/Ft – Pounds
1/8″ .405   10S .049 .307 .1863
    40 40S Std. .068 .269 .2447
    80 80S Ex. Hvy. .095 .215 .3145
             
1/4″ .540   10S .065 .410 .3297
    40 40S Std. .088 .364 .4248
    80 80S Ex. Hvy. .119 .302 .5351
             
3/8″ .675   10S .065 .545 .4235
    40 40S Std. .091 .493 .5676
    80 80S Ex. Hvy. .126 .423 .7388
             
1/2″ .840   5S .065 .710 .5383
      10S .083 .674 .6710
    40 40S Std. .109 .622 .8510
    80 80S Ex. Hvy. .147 .546 1.088
    160   .188 .466 1.309
      XX Hvy. .294 .252 1.714
             
3/4″ 1.050   5S .065 .920 .6838
      10S .083 .884 .8572
    40 40S Std. .113 .824 1.131
    80 80S Ex. Hvy. .154 .742 1.474
    160   .219 .614 1.944
      XX Hvy .308 .434 2.441
             
1″ 1.315   5S .065 1.185 .8678
      10S .109 1.097 1.404
    40 40S Std. .133 1.049 1.679
    80 80S Ex. Hvy. .179 .957 2.172
    160   .250 .815 2.844
      XX Hvy. .358 .599 3.659
             
1 1/4″ 1.660   5S .065 1.530 1.107
      10S .109 1.442 1.806
    40 40S Std. .140 1.380 2.273
    80 80S Ex. Hvy. .191 1.278 2.997
    160   .250 1.160 3.765
      XX Hvy. .382 .896 5.214
             
1 1/2″ 1.900   5S .065 1.770 1.274
      10S .109 1.682 2.085
    40 40S Std. .145 1.610 2.718
    80 80S Ex. Hvy. .200 1.500 3.631
    160   .281 1.338 4.859
      XX Hvy. .400 1.100 6.408
             
2″ 2.375   5S .065 2.245 1.604
      10S .109 2.157 2.638
    40 40S Std. .154 2.067 3.653
    80 80S Ex. Hvy. .218 1.939 5.022
    160   .344 1.689 7.462
      XX Hvy. .436 1.503 9.029
             
2 1/2″ 2.875   5S .083 2.709 2.475
      10S .120 2.635 3.531
    40 40S Std. .203 2.469 5.793
    80 80S Ex. Hvy. .276 2.323 7.661
    160   .375 2.125 10.01
      XX Hvy. .552 1.771 13.69
             
3″ 3.500   5S .083 3.334 3.029
      10S .120 3.260 4.332
    40 40S Std. .216 3.068 7.576
    80 80S Ex. Hvy. .300 2.900 10.25
    160   .438 2.624 14.32
      XX Hvy. .600 2.300 18.58
Size O.D. I. P. S. Schedule Wall I.D. Wt/Ft
3 1/2″ 4.000 5 5S .083 3.834 3.472
    10 10S .120 3.760 4.973
    40 40S Std. .226 3.548 9.109
    80 80S Ex. Hvy. .318 3.364 12.50
      XX Hvy .636 2.728 22.85
             
4″ 4.500   5S .083 4.334 3.915
      10S .120 4.260 5.613
    40 40S Std. .237 4.026 10.79
    80 80S Ex. hvy. .337 3.826 14.98
    120   .438 3.624 19.00
    160   .531 3.438 22.51
      XX Hvy. .674 3.152 27.54
             
4 1/2″ 5.000   40 Std. .247 4.506 12.53
      80 Ex. Hvy .355 4.290 17.61
      XX Hvy. .710 3.580 32.43
             
5″ 5.563   5S .109 5.345 6.349
      10S .134 5.295 7.770
    40 40S Std. .258 5.047 14.62
    80 80S Ex. Hvy. .375 4.813 20.78
    120   .500 4.563 27.04
    160   .625 4.313 32.96
      XX Hvy. .750 4.063 38.55
             
6″ 6.625   5S .109 6.407 7.585
      10S .134 6.357 9.289
    40 40S Std. .280 6.065 18.97
    80 80S Ex.Hvy. .432 5.761 28.57
    120   .562 5.491 36.39
    160   .719 5.189 45.35
      XX Hvy. .864 4.897 53.16
             
7″ 7.625 40 Std. .301 7.023 23.57
    80 Ex. Hvy. .500 6.625 38.05
      XX Hvy. .875 5.875 63.08
             
8″ 8.625   5S .109 8.407 9.914
      10S .148 8.329 13.40
    20   .250 8.125 22.36
    30   .277 8.071 24.70
    40 40S Std. .322 7.981 28.55
    60   .406 7.813 35.64
    80 80S Ex. Hvy. .500 7.625 43.39
    100   .594 7.439 50.95
    120   .719 7.189 60.71
    140   .812 7.001 67.76
      XX Hvy. .875 6.875 72.42
    160   .906 6.813 74.89
Size O.D. I. P. S. Schedule Wall I.D. Wt/Ft
9″ 9.625 40 Std. .342 8.941 33.90
    80 Ex. Hvy. .500 8.625 48.72
      XX Hvy. .875 7.875 81.77
             
10″ 10.750   5S .134 10.482 15.19
      10S .165 10.420 18.70
    20   .250 10.250 28.04
    30   .307 10.136 34.24
    40 40S Std. .365 10.020 40.48
    60 80S Ex. Hvy. .500 9.750 54.74
    80   .594 9.564 64.43
    100   .719 9.314 77.03
    120   .844 9.064 89.29
    140   1.000 8.750 104.13
    160   1.125 8.500 115.64
             
11″ 11.750 40 Std. .375 11.00 45.55
    80 Ex. Hvy. .500 10.750 60.07
      XX Hvy. .875 10.000 101.63
             
12″ 12.750   5S .165 12.420 22.18
      10S .180 12.390 24.20
    20   .250 12.250 33.38
    30   .330 12.090 43.77
      40S Std. .375 12.000 49.56
    40   .406 11.938 53.52
      80S Ex. Hvy. .500 11.750 65.42
    60   .562 11.626 73.15
    80   .688 11.376 88.63
    100   .844 11.064 107.32
    120   1.000 10.750 125.49
    140   1.125 10.500 139.67
    160   1.312 10.126 160.27
             
14″ 14.000 10   .250 13.500 36.71
    20   .312 13.376 45.61
    30 Std. .375 13.250 54.57
    40   .438 13.124 63.44
      Ex. Hvy. .500 13.000 72.09
    60   .594 12.814 85.05
    80   .750 12.500 106.13
    100   .938 12.126 130.85
    120   1.094 11.814 150.9
    140   1.250 11.500 170.21
    160   1.406 11.188 189.1
             
16″ 16.000 10   .250 15.500 42.05
    20   .312 15.376 52.27
    30 Std. .375 15.250 62.58
    40 Ex Hvy. .500 15.000 82.77
    60   .656 14.688 107.5
    80   .844 14.314 136.61
    100   1.031 13.938 164.82
    120   1.219 13.564 192.43
    140   1.438 13.124 223.64
    160   1.594 12.814 245.25
Size O.D. I. P. S. Schedule Wall I.D. Wt/Ft
18″ 18.000 10   .250 17.500 47.39
    20   .312 17.376 58.94
      Std. .375 17.250 70.59
    30   .438 17.124 82.15
      Ex. Hvy. .500 17.000 93.45
    40   .562 16.876 104.67
    60   .750 16.500 138.17
    80   .938 16.126 170.92
    100   1.156 15.688 207.96
    120   1.375 15.250 244.14
    140   1.562 14.876 274.22
    160   1.781 14.438 308.5
             
20″ 20.000 10   .250 19.500 52.73
    20 Std. .375 19.250 78.60
    30 Ex. Hvy. .500 19.000 104.13
    40   .594 18.814 123.11
    60   .812 18.376 166.4
    80   1.031 17.938 208.87
    100   1.281 17.438 256.1
    120   1.500 17.000 296.37
    140   1.750 16.500 341.09
    160   1.969 16.064 379.17
             
22″ 22.000 10   .250 21.500 58.07
    20 Std. .375 21.250 86.61
    30 Ex. Hvy. .500 21.000 114.81
    60   .875 20.250 197.41
    80   1.125 19.750 250.81
    100   1.375 19.250 302.88
    120   1.625 18.750 353.61
    140   1.875 18.250 403.00
    160   2.125 17.750 451.06
             
24″ 24.000 10   .250 23.500 63.41
    20 Std. .375 23.250 94.62
      Ex. Hvy. .500 23.000 125.49
    30   .562 22.876 140.68
    40   .688 22.626 171.29
    60   .969 22.064 238.35
    80   1.219 21.564 296.58
    100   1.531 20.938 367.39
    120   1.812 20.376 429.39
    140   2.062 19.876 483.1
This table is intended to give a “quick and dirty” comparison of American, British, German, and Japanese Standards for common boiler tubing and boiler piping specifications. This table must not be used for design. There is seldom an exact match between specifications in two different Standards. Use this table only to find an approximate equivalent, then compare the details of the specifications to determine if substitution is permissable. The best source I have found (and it’s neither completely accurate nor easy to use) is the Handbook of Comparative World Steel Standards, published by ASTM. It’s a revision of a handbook originally done by the Japanese, and it’s still half in Japanese, but it seems to be about the only thing available, short of buying all of the individual Standards. You can buy it off the Web at www.astm.org. Click on the Bookstore, then Technical Publications, then Steel. You may have to up the credit limit on your plastic.
 
The table is divided into tubing, (which is used inside the boiler setting, as in steam generating tubes, wall tubes, superheaters and economizers) and piping (which is used ouside the boiler setting, as in headers, steam piping, and feedwater lines). The German (DIN) Standards don’t appear to differentiate between the two. Heat exchanger tube specs are not included here. In general, the Japanese (JIS) specs match up pretty well with the American(ASME/ASTM), while the British (BS) and German specs are usually more difficult to find an equivalent in.
 
We welcome input on any poor choices, downright errors, or blank spots in the table.  Please feel free to contact us with any discrepancies you may see.
 

ASME/ASTM BS DIN JIS
Tubing Specs      
SA-178 A 3059 ERW 320 17177 St37.8 G 3461 STB35 E
SA-178 C 3059 ERW 440 17177 St42.8 G 3461 STB42 E
SA-178 D     G 3461 STB52 E
SA-192 3059 S1 360 17175 St35.8 G 3461 STB35 S
SA-210 A1 3059 S1 440 17175 St45.8 G 3461 STB52 S
SA-210 C     G 3461 STB42 S
SA-209 T1 3059 S1 243 17175 15Mo3 G 3462 STBA12 S
SA-209 T1a     G 3462 STBA13 S
SA-213 T2     G 3462 STBA20 S
SA-213 T11 3059 S1 620-460 17175 13CrMo4-4 G 3462 STBA23
SA-213 T12   17175 13CrMo4-4  
SA-213 T22 3059 S1 622-490 17175 10CrMo9-10 G 3462 STBA24
SA-213 T23 (not appr)      
SA 213 T24 (not appr)   17175 7CrMoVTiB10-10  
SA-213 T5     G 3462 STBA25
SA-213 T9 3059 S1 629-470   G 3462 STBA26
SA-213 T91 3059-2 Gr. 91 17175-X10CrMoVNb9-1 G 3462 STBA28
SA-213 Tp-304   17456 X2CrNi1911 G3463 SUS304TB
SA-213 Tp 304H 3059 CFS304S51   G3463 SUS304HTB
SA-213 Tp 316   17456 X5CrNiMo17122 G3463 SUS316TB
SA-213 Tp 316H 3059 CFS316S51   G3463 SUS316HTB
SA-213 Tp 321   17456 X6CrNiTi1810 G3463 SUS321TB
SA-213 Tp 321H 3059 CFS321S51   G3463 SUS321HTB
SA-213 Tp 347   17456 X5CrNiNB1810 G3463 SUS347TB
SA-213 Tp 347H 3059 CFS347S51   G3463 SUS347HTB
Pipe Specs      
SA-53A 3602 HFS360 17175 St35.8 G 3454 STPG38
SA-53B 3602 HFS460 17175 St45.8 G 3454 STPG42
SA-106B 3602 CFS460 17175 St45.8 G 3456 STPT42
SA-106C 3602 CFS460   G 3456 STPT49
SA-335-P11 3604 CFS621 17175 13CrMo44 G 3458 STPA23
SA-335-P22 3604 CFS622 17175 10CrMo910 G 3458 STPA24
SA-335-P9 3604 CFS629-470   G 3458 STPA26
SA-335-P91 3604-2 Gr. 91  
 
ASME – American Society of Mechanical Engineers
ASTM – American Society for Testing and Materials (ASTM specs are generally identical to ASME).
BS – British Standards
DIN – Deutsche Industrie Normen (German Standards)
JIS – Japanese Industrial Standards