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

Forging (ASTM A 182)

Plate (ASTM A 240)4

   

 

Bar5

         

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

Flange Type

 

Specifications

 

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

 

N

ominal Pipe Sizes

   
 

< NPS 26

>NPS 26

>NPS 26

DN 10 to DN 4000

> NPS 26

   

Nom

inal Pressure (Cl

ass)

 
 

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

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):

G (raised face diameter)

< NPS 24

±0.03

±0.76

> NPS 26, with 0.06 in raised face

±0.08

±2.03

> NPS 26, with0.25 in raised face

±0.04

±1.02

I (bolt hole diameter)

All

No tolerance in B16.5 or B16.47

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):

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

       

Slip on (see page 8-17), Lap Joint (see page 8-32 for dimensions) and Socket Welding (see page 8-30 fordimensions) Flanges:

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

       

Threaded Flanges (see page 8-40 for dimensions):

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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