Gray Iron Pipe Flanges and Flanged Fittings

Classes 25, 125, and 250

AN A MERICAN NA TIONAL S T AND ARD

ASME B16.1-2015

(Revision of ASME B16.1-2010)

ASME B16.1-2015

(Revision of ASME B16.1-2010)

Gray Iron Pipe Flanges and Flanged Fittings

Classes 25, 125, and 250

AN AMERICAN NA TIONAL S T AND ARD

Two Park Avenue • New York, NY • 10016 USA

Date of Issuance: December 28, 2015

The next edition of this Standard is scheduled for publication in 2020.

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The American Society of Mechanical Engineers Two Park Avenue, New York, NY 10016-5990

Copyright © 2015 by

THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS

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CONTENTS

Foreword iv

Committee Roster vi

Correspondence With the B16 Committee vii

Summary of Changes viii

List of Changes in Record Number Order ix

1. Scope 1

2. General 1

3. Pressure–Temperature Ratings 1

4. Size 2

5. Marking 2

6. Materials 2

7. Fitting Dimensions and Tolerances 2

8. Bolt, Nut, and Gasket Dimensions 4

9. Hydrostatic Tests 5

10. Certifications 5

Figures

1. Method of Designating Outlets of Reducing Fittings in Specifications 6

2. Drain Connections 7

3. Method of Designating Location of Tapped Holes for Drains When Specified 8

Tables

1. Pressure–Temperature Ratings 9

2. Class 250 Flange and Bolting Dimensions 10

3. Dimensions of Class 25 Gray Iron Flanged Fittings 12

4. Dimensions of Class 125 Gray Iron Flanged Fittings 14

5. Dimensions of Class 250 Gray Iron Flanged Fittings 19

6. Dimensions of Anchorage Bases for Straight and Reducing Class 125 Tees 24

7. Dimensions of Anchorage Bases for Straight and Reducing Class 250 Tees 26

8. Class 25 Flange and Bolting Dimensions 28

9. Class 125 Flange and Bolting Dimensions 29

10. Minimum Thread Length 30

    Mandatory Appendices

    1. Dimensions of Fittings in U.S. Customary Units 31

    2. References 57

Nonmandatory Appendix

A Quality System Program 58

FOREWORD

In 1894, the American Society of Mechanical Engineers (ASME) adopted a standard flange template (“ASME Standard”) for low-pressure service. A “Manufacturers Standard” for pressures up to 250 psi followed in 1901. Around 1910, a group of fittings manufacturers formed an organization that was the forerunner of the present Manufacturers Standardization Society of the Valve and Fittings Industry (MSS) and undertook the design of a line of flanged fittings. A document covering this work was published in 1912.

During the years 1912–1914, a Joint Committee of the ASME and the Manufacturers Committee formulated compromise standard dimensions for pipe flanges and flanged fittings for use under saturated steam pressures of 125 psi and 250 psi pressure ranges. The Joint Committee’s report was accepted at a conference attended by representatives of ASME, the Manufacturers Committee, the U.S. government, and the National Association of Master Steam and Hot Water Fitters. ASME published this report as the “American Standard for Pipe Flanges, Fittings and Their Bolting” in 1914. In 1918, work was started on standards for 50 lb steam flanges and for 800 lb, 1,200 lb, and 3,000 lb hydraulic flanges, which were subsequently approved by this group.

In 1921, the American Engineering Standards Committee, later known as the American Standards Association (ASA), United States of America Standards Institute (USAS), and more recently, the American National Standards Institute (ANSI), organized Sectional Committee B16 to unify and further develop national standards for pipe flanges and fittings (and later for valves and gaskets). Cosponsors of the B16 Committee were ASME, MSS, and the Heating and Piping Contractors Association [now the Mechanical Contractors Association of America (MCAA)]. Work already in progress on flanges and flanged fittings was assigned to Subcommittee 1 (now Subcommittee A). Following approval by the Subcommittee, the B16 Committee, the cosponsors, and ASA, the standards were published in 1928.

In later work, Subcommittee 1 developed the 25 lb Flange and Flanged Fitting Standard (approved in 1931 as ASA B16b2), which replaced the 50 lb standard that had been originally approved in 1918. Work on the 800 lb Hydraulic Flange Standard was published as ASA B16b1 in 1931. Revision of thicknesses, tolerances, and service pressure ratings of the 125 lb and 250 lb flanges and flanged fittings led to approval and publication of ASA B16a-1939.

An American war standard entitled “Pressure Ratings for Cast Iron Flanges and Flanged Fittings, 125 lb” (ASA B16a1) was published in 1943. A complete review of the 125 lb and 250 lb standards resulted in new editions of each: ASA B16.1-1948 and ASA B16.2-1948. In 1960, editions of B16.1 and B16.2 were issued in which ratings were presented in graphic form and special requirements were added for testing flanges.

A review of all gray iron flange and flanged fittings standards initiated in 1962 resulted in the withdrawal of B16.16, “300 lb Refrigerant Flanges and Flanged Fittings” and the combining of the remaining standard into a single document, with B16.1 and B16.2 coming together as USAS B16.1-1967. In this edition, the presentation of ratings was restored to tabular form.

The increasing use of higher grades of gray iron necessitated the establishment of a second set of ratings for the smaller sizes. A revised edition published as ANSI B16.1-1975 incorporated these new ratings along with metric (SI) equivalents for dimensions and minor corrections to the 1967 edition text.

In 1982, American National Standards Committee B16 was recognized as an ASME Committee operating under procedures accredited by ANSI. Following approval by the ASME B16 Subcommittee A and B16 Committee, ANSI approved ASME/ANSI B16.1-1989 on March 8, 1989. Changes included revised marking requirements, revised bolt length increments (1⁄2 in. rather than 1⁄4 in.), elimination of metric equivalents, a correction of the Class 800 flange raised-face height to 0.25 in. from the 0.06 in. shown previously, and editorial changes to the text.

In the 1998 edition of ASME B16.1, Reference Standards were updated, a Quality System Program Annex was added, Class 800 was deleted, and several editorial revisions were made.

Following approval by ASME B16 Subcommittee B and B16 Main Committee, ANSI approved ASME B16.1-1998 on November 20, 1998.

Work was started in 1999 to revise the standard to include metric units as the primary reference units while maintaining U.S. Customary units in either parenthetical or separate forms. Following approval of the Standard Committee and ASME, approval as an American National Standard was given by ANSI on July 8, 2005, with the new designation ASME B16.1-2005.

In the 2010 edition of ASME B16.1, the Scope was separated into its own paragraph with all following paragraphs renumbered accordingly, references were updated, and several editorial revisions were made. Following approval of the B16 Standards Committee, approval as an American National Standard was given by ANSI on November 17, 2010.

In this 2015 Edition, provisions have been made to provide bolt hole tolerances that are appro- priate to this Standard. Following the approval by the ASME B16 Standards Committee, approval as an American National Standard was given by ANSI on July 29, 2015, with the new designation ASME B16.1-2015.

All requests for interpretation or suggestions for revision should be sent to the Administrative Secretary B16, The American Society of Mechanical Engineers, Two Park Avenue, New York, NY 10016-5990.

ASME B16 COMMITTEE

Standardization of Valves, Flanges, Fittings, Gaskets, and Valve Actuators

(The following is the roster of the Committee at the time of approval of this Standard.)

STANDARDS COMMITTEE OFFICERS

R. Bojarczuk, Chair

C. E. Davila, Vice Chair

C. E. O’Brien, Secretary

A. Appleton, Alloy Stainless Products Co., Inc.

R. W. Barnes, Anric Enterprises, Inc.

K. Barron, Ward Manufacturing

W. B. Bedesem, Consultant

STANDARDS COMMITTEE PERSONNEL

T. A. McMahon, Emerson Process Management

M. L. Nayyar, NICE

C. E. O’Brien, The American Society of Mechanical Engineers

W. H. Patrick, The Dow Chemical Co.

R. Bojarczuk, Exxon Mobil Research and Engineering Co.

A. M. Cheta, Shell Exploration and Production Co.

M. A. Clark, Nibco, Inc.

G. A. Cuccio, Capitol Manufacturing Co.

1. E. Davila, Crane Energy

2. R. Frikken, Becht Engineering Co.

R. B. Hai, RBH Associates

K. A. Hettler, U.S. Coast Guard

G. A. Jolly, Flowserve/Gestra, USA

M. Katcher, Haynes International

D. W. Rahoi, Consultant

R. A. Schmidt, Canadoil

H. R. Sonderegger, Fluoroseal Valves USA

W. M. Stephan, Flexitallic LP

F. R. Volgstadt, Volgstadt and Associates, Inc.

D. A. Williams, Southern Co. Generation

F. Feng, Delegate, China Productivity Center for Machinery

P. V. Craig, Contributing Member, Jomar Group

B. G. Fabian, Contributing Member, Pennsylvania Machine Works

D. F. Reid, Contributing Member, VSP Technologies

C. Stout, Contributing Member, Mueller Industries

SUBCOMMITTEE B — THREADED FITTINGS (EXCEPT STEEL), FLANGES, AND FLANGED FITTINGS (B16)

K. Barron, Chair, Ward Manufacturing

G. T. Walden, Vice Chair, Wolseley

C. R. Ramcharran, Secretary, The American Society of Mechanical Engineers

W. Bliss, Tyler Pipe Co.

M. A. Clark, Nibco, Inc.

J. R. Holstrom, Val-Matic Valve and Manufacturing Co.

D. Hunt, Jr., Fastenal

W. H. LeVan, Cast Iron Soil Pipe Institute

J. K. Schultz, Conine Manufacturing Co., Inc.

G. L. Simmons, Charlotte Pipe and Foundry

A. A. Knapp, Contributing Member, A. Knapp and Associates

P. I. McGrath, Jr., Contributing Member, Consultant

CORRESPONDENCE WITH THE B16 COMMITTEE

General. ASME Standards are developed and maintained with the intent to represent the consensus of concerned interests. As such, users of this Standard may interact with the Committee by requesting interpretations, proposing revisions or a Case, and attending Committee meetings. Correspondence should be addressed to:

Secretary, B16 Standards Committee

The American Society of Mechanical Engineers Two Park Avenue

New York, NY 10016-5990

As an alternative, inquiries may be submitted via e-mail to: SecretaryB16@asme.org.

Proposing Revisions. Revisions are made periodically to the Standard to incorporate changes that appear necessary or desirable, as demonstrated by the experience gained from the application of the Standard. Approved revisions will be published periodically.

The Committee welcomes proposals for revisions to this Standard. Such proposals should be as specific as possible, citing the paragraph number(s), the proposed wording, and a detailed description of the reasons for the proposal, including any pertinent documentation.

Proposing a Case. Cases may be issued for the purpose of providing alternative rules when justified, to permit early implementation of an approved revision when the need is urgent, or to provide rules not covered by existing provisions. Cases are effective immediately upon ASME approval and shall be posted on the ASME Committee Web page.

Requests for Cases shall provide a Statement of Need and Background Information. The request should identify the Standard and the paragraph, figure, or table number(s), and be written as a Question and Reply in the same format as existing Cases. Requests for Cases should also indicate the applicable edition(s) of the Standard to which the proposed Case applies.

Interpretations. Upon request, the B16 Committee will render an interpretation of any require- ment of the Standard. Interpretations can only be rendered in response to a written request sent to the Secretary of the B16 Standards Committee.

The request for interpretation should be clear and unambiguous. It is further recommended that the inquirer submit his/her request in the following format:

Subject: Cite the applicable paragraph number(s) and the topic of the inquiry.

Edition: Cite the applicable edition of the Standard for which the interpretation is being requested.

Question: Phrase the question as a request for an interpretation of a specific requirement suitable for general understanding and use, not as a request for an approval of a proprietary design or situation. The inquirer may also include any plans or drawings that are necessary to explain the question; however, they should not contain proprietary names or information.

Requests that are not in this format may be rewritten in the appropriate format by the Committee prior to being answered, which may inadvertently change the intent of the original request.

ASME procedures provide for reconsideration of any interpretation when or if additional information that might affect an interpretation is available. Further, persons aggrieved by an interpretation may appeal to the cognizant ASME Committee or Subcommittee. ASME does not “approve,” “certify,” “rate,” or “endorse” any item, construction, proprietary device, or activity. Attending Committee Meetings. The B16 Standards Committee regularly holds meetings and/or telephone conferences that are open to the public. Persons wishing to attend any meeting

and/or telephone conference should contact the Secretary of the B16 Standards Committee.

ASME B16.1-2015 SUMMARY OF CHANGES

Following approval by the B16 Committee and ASME, and after public review, ASME B16.1-2015 was approved by the American National Standards Institute on July 29, 2015.

ASME B16.1-2015 includes editorial changes, revisions, and corrections, which are identified by a margin designator, (15), placed next to the affected area.

(13-1932, 14-1542)

58 Mandatory Appendix II References updated (10-1036)

LIST OF CHANGES IN RECORD NUMBER ORDER

Record Number Change

10-1036 Updated referenced standards within B16.1 to reflect the latest edition.

13-1932 In Table 9, NPS 14, 54, 60, and 72 for “Diameter of Bolts” corrected by errata. 14-1542 In Table 9, NPS 14 for “Minimum Thickness of Flange” corrected by errata.

14-2394 Added new paras. 7.6.2 and 8.1(a), which provide bolt hole tolerances that are appropriate for addition to B16.1. Revising this Standard to require bolt hole toler- ances eliminates the issues of oversized bolt holes and high compression loads under the bolt heads. Paragraphs 7.6.2 through 7.6.5 were redesignated as 7.6.3 through 7.6.6. Paragraphs 8.1(a) and (b) were redesignated as 8.1(b) and (c).

Deleted previous para. 8.1(c).

INTENTIONALLY LEFT BLANK

ASME B16.1-2015

GRAY IRON PIPE FLANGES AND FLANGED FITTINGS

Classes 25, 125, and 250

1. SCOPE

   This Standard covers Classes 25, 125, and 250 Gray Iron Pipe Flanges and Flanged Fittings. It includes

   1. pressure–temperature ratings

   2. sizes and method of designating openings of reducing fittings

   3. marking

   4. materials

   5. dimensions and tolerances

   6. bolting and gaskets

   7. pressure testing

      
      

2. GENERAL

1. References

   Standards and specifications adopted by reference in this Standard are shown in Mandatory Appendix II, which is part of this Standard. It is not considered practi- cal to identify the specific edition of each referenced standard and specification in the text, when referenced. Instead, the specific editions of the referenced standards and specifications are listed in Mandatory Appendix II.

   
   

2. Quality Systems

Requirements relating to the product manufacturer’s Quality System Programs are described in Nonmandatory Appendix A.

(15) 2.3 Relevant Units

This Standard states values in both SI and U.S. Customary units. As an exception, diameter of bolts and flange bolt holes are expressed in inch units only. These systems of units are to be regarded separately as stan- dard. Within the text, the U.S. Customary units are shown in parentheses or in separate tables that appear in Mandatory Appendix I. The values stated in each system are not exact equivalents; therefore, it is required that each system of units be used independently of the other. Except for diameter of bolts and flange bolt holes, combining values from the two systems constitutes non- conformance with the Standard.

1. Service Conditions

   Criteria for selection of materials suitable for particu- lar fluid service are not within the scope of this Standard.

   
   

2. Convention

   For determining conformance with this Standard, the convention for fixing significant digits where limits (maximum and minimum values) are specified shall be as defined in ASTM E29. This requires that an observed or calculated value be rounded off to the nearest unit in the last right-hand digit used for expressing the limit. Decimal values and tolerances do not imply a particular method of measurement.

   
   

3. Denotation

   1. Pressure Rating Designation. Class, followed by a dimensionless number, is the designation for pressure–temperature ratings as follows:

      Class 25 125 250

   2. Size. NPS, followed by a dimensionless num- ber, is the designation for nominal flange or flange fitting size. NPS is related to the reference nominal diameter, DN, used in international standards. The relationship is, typically, as follows:

GENERAL NOTE: For NPS  4, the related DN p 25 (NPS).

3 PRESSURE–TEMPERATURE RATINGS

3.1 General

Pressure–temperature ratings are maximum allow- able working pressures in bar units at the temperature in degrees Celsius shown in Table 1 for the applicable material and class designation. Table I-1 of Mandatory Appendix I lists pressure–temperature ratings using psi units for pressure at the temperature in degrees Fahrenheit. For intermediate temperatures, linear inter- polation is permitted. Interpolation between class desig- nations is not permitted.

(15)

1