ANSI/ASME flanges tolerance face type face finish
PDF: ANSI/ASME flanges tolerance face type face finish
Specifications
Refer to page 8-1 for a list of flange specifications (with page references) covered in this Section.
Manufacture
Summary of materials used for flanges
|
ASME/ANSI B16.5 |
ASME B16.47 Series A (or MSS SP-441) |
ASME B16.47 Series B ( or API 605) |
BS 4504 |
BS 3293 |
BS 103 |
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Forging (ASTM A 182) |
✔ |
✔ |
✔ |
✔ |
✔ |
✔ |
|
Plate (ASTM A 240)4 |
✔ |
✔ |
✔ |
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Bar5 |
✔ |
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Casting6 |
✔ |
✔ |
✔ |
Notes 1 MSS SP-44 flanges are designated Series A flanges in ASME B16.47. 2 API 605 has been cancelled. API 605 flanges are designated Series B flanges in ASME B16.47. 3 BS 10, although obsolete, remains in use for light weight economy stainless steel flanges. 4 Within specification ANSI B16.5, plate can only be used to provide blind flanges. 5 Most small BS 10 flanges are made from bar. 6 Castings are not included in this manual.
- Materials. Most standards specify the material ❍ Face Finish. The finish on the face of a flange is from which the flange is produced. The purchaser measured as an Arithmetical Average Roughness should specify the exact requirements. Height (AARH). The finish is determined by the
- Flange Sizes. All sizes and grades compatible to standard used. For example, ANSI B16.5 standard pipe ranges and wall thicknesses specifies face finishes within a range 125AARH (pressure ratings) are available. The table below 500AARH (3.2 Ra to 12.5 Ra). Other finishes are provides a summary. available on request, for example 1.6 Ra max,
- Flange Face. There are various face 1.6/3.2 Ra, 3.2/6.3 Ra or 6.3/12.5 Ra. The range configurations for flanges. Typically: flat face, 3.2/6.3 Ra is most common. raised face, tongue and groove, ring joint.
Summary of flange sizes specified by common standards
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Flange Type |
Specifications |
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ASME/ANSIB16.5 |
ASME B16.47 Series A (or MSS SP-441) |
ASME B16.47 Series B (or API 6052) |
BS 4504 (ISO 7005-1) |
BS 3293 |
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|
N |
ominal Pipe Sizes |
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< NPS 26 |
>NPS 26 |
>NPS 26 |
DN 10 to DN 4000 |
> NPS 26 |
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Nom |
inal Pressure (Cl |
ass) |
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Class (lb) |
Class (lb) |
Class (lb) |
PN (bar) |
Class (lb) |
|
|
Weld Neck |
150-2500 |
150-900 |
75-900 |
2.5-40 |
150-600 |
|
Slip-on |
150-1500 |
– |
– |
2.5-40 |
150-600 |
|
Blind |
150-2500 |
300-900 |
300-900 |
2.5-40 |
– |
|
Lap Joint |
150-2500 |
– |
– |
6-403 |
– |
|
Socket Weld |
150-1500 |
– |
– |
N/A |
– |
|
Threaded |
150-2500 |
– |
– |
6-40 |
– |
|
Flat/Raised Facings |
As above |
As above |
As above |
As above |
As above |
|
Ring Joint Facings |
150-2500 |
300-900 |
300-900 |
2.5-40 |
300-600 |
|
Other Facings |
150-25003 |
– |
– |
2.5-40 |
– |
Notes
1 MSS SP-44 flanges are designated Series A flanges in ASME B16.47. It also covers flanges in the range NPS 12 to 24, these being equivalent to ASME/ANSI B16.5 flanges in the same range (except for the addition of NPS 22 in MSS SP-44).
2 API 605 has been cancelled. API 605 flanges are designated Series B flanges in ASME B16.47. Ranges quoted are based on ASME B16.47 Series B.
American national standards ASME/ANSI B16.5 and B16.47 together cover pipe flanges up to NPS 60 (NPS 48 is the largest detailed in this summary). ASME/ANSI B16.47 covers two series of flanges, Series A which is equivalent to MSS SP-44 (the 1996 Edition of MSS SP-44 complies with B16.47 tolerances), and Series B which is equivalent to API 605 (API 605 is now cancelled).
Dimensions and Tolerances
Tolerances on flange dimensions (ASME/ANSI B16.5 and B16.47, and MSS SP-44)
|
Dimension |
Range |
Tolerance |
|
|
in |
mm |
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General and Blind Flanges (For blind flange dimensions see page 8-23 for B16.5, page 8-46 for B16.47 Series A / MSS SP-44 and page 8-51 for B16.47 Series B / API 605): |
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|
G (raised face diameter) |
< NPS 24 |
±0.03 |
±0.76 |
|
> NPS 26, with 0.06 in raised face |
±0.08 |
±2.03 |
|
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> NPS 26, with0.25 in raised face |
±0.04 |
±1.02 |
|
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I (bolt hole diameter) |
All |
No tolerance in B16.5 or B16.47 |
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J (bolt circle diameter) |
All |
±0.06 |
±1.52 |
|
Centre to centre of adjacent bolt holes |
All |
±0.03 |
±0.76 |
|
Eccenticity of bolt circleand machined facing diameters |
< NPS 21/2 |
±0.03 |
±0.76 |
|
> NPS 3 |
±0.06 |
±1.52 |
|
|
Weld Neck Flanges1 (For dimensions see page 8-10 for B16.5, page 8-46 for B16.47 Series A / MSS SP-44 and page 8-51 for B16.47 Series B / API 605): |
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|
D (overall length) |
< NPS 4 |
+0.06 |
+1.52 |
|
NPS 5 to 10 |
+0.06, -0.12 |
+1.52, -3.05 |
|
|
NPS 12 to 24 |
+0.12, -0.18 |
+3.05, -4.57 |
|
|
> NPS 26 |
±0.19 |
±4.83 |
|
|
Thickness of hub |
All |
> 87.5% of pipe nominal wall thickness |
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Slip on (see page 8-17), Lap Joint (see page 8-32 for dimensions) and Socket Welding (see page 8-30 fordimensions) Flanges: |
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B (inside diameter, or bore) |
< NPS 10 |
+0.03, -0.0 |
+0.76, -0.0 |
|
> NPS 12 |
+0.06, -0.0 |
+1.52, -0.0 |
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Threaded Flanges (see page 8-40 for dimensions): |
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B (counterbore)(Not applicable forClass 150 lb) |
< NPS 10 |
+0.03, -0.0 |
+0.76, -0.0 |
|
> NPS 12 |
+0.06, -0.0 |
+1.52, -0.0 |
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