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By Authority Of
THE UNITED STATES OF AMERICA

Legally Binding Document
By the Authority Vested By Part 5 of the United States Code § 552(a) and
Part 1 of the Code of Regulations § 51 the attached document has been duly
INCORPORATED BY REFERENCE and shall be considered legally
binding upon all citizens and residents of the United States of America.
HEED THIS NOTICE: Criminal penalties may apply for noncompliance.

e
Document Name: ASME B31G: Manual for Determining the Remaining
Strength of Corroded Pipelines

CFR Section(s):

49 CFR 192.485(c)

Standards Body:

American Society of Mechanical Engineers

Official Incorporator:
THE EXECUTIVE DIRECTOR

OFFICE OF THE FEDERAL REGISTER
WASHINGTON, D.C.

AN AMERICAN NATIONAL STANDARD
ASME CODE FOR PRESSURE PIPING, 831

Manual for Determining
the Remaining Strength
of Corroded Pipelines
-

A Supplement to ASME 831 Code
for Pressure Piping

ASME 831G .. 1991
(REVISION OF ANSI/ASME B31G-1984)

~
@)

The American Society of
Mechanical Engineers

' - - - - - - - 345 East 47th Street, New York, N.Y. 10017 -

Date of Issuance: June 27,1991

The 1991 edition of this Manual will be revised when public comment or
Committee actions necessitate the issuance of a new edition, or it will be
reviewed and reaffirmed 5 years from the date of approval of this edition. No
addenda service is provided with this publication. Written interpretations of
the requirements of this Manual will not be issued to the current edition.

ASME is the registered trademark of The American Society of Mechanical Engineers.

This code or standard was developed under procedures accredited as meeting the criteria for
American National Standards. The Consensus Committee that app'roved the code or standard
was balanced to assure that individuals from competent and concerned interests have had an
opportunity to participate. The proposed code or standard was made available for public review
and comment which provides an opportunity for additional public input from industry, academia,
regulatory agencies, and the public-at-Iarge.
ASME does not "approve," "rate," or "endorse" any item, construction, proprietary device, or
activity.
ASME does not take any position with respect to the validity of any patent rights asserted in
connection with any items mentioned in this document, and does not undertake to insure anyone
utilizing a standard against liability for infringement of any applicable Letters Patent, nor assume
any such liability. Users of a code or standard are expressly advised that determination of the
validity of any such patent rights, and the risk of infringement of such rights, is entirely their own
responsibility.
Participation by federal agency representative(s) or person(s) affiliated with industry is not to
be interpreted as government or industry endorsement of this code or standard.
ASME accepts responsibility'for only those interpretations issued in accordance with governing
ASME procedures and policies which preclude the issuance of interpretations by individual volunteers.

No part of this document may be reproduced in any form,
in an electronic retrieval system or otherwise,
without the prior written permission of the publisher.

Copyright © 1991 by
THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS
All Rights Reserved
Printed in the U.S.A.

FOREWORD
(This Foreword is not a part of ASME B31G-1991.)

It is recognized by pipeline companies that some sections of high pressure pipelines t
particularly those installed a number of years ago, have experienced some corrosion.
Where corrosion is found, pipeline operators have been deeply concerned about the need
for a method of determining the remaining strength of these corroded areas. If the
corrosion does not penetrate the pipe wall, what is the pressure containing capability of
the remaining pipe metal in tenns of its ability to continue to operate safely at the
maximum allowable operating pressure (MAOP) of the pipeline system? Thus, one of
the needs of the pipeline industry has been a procedure that will help operators, particularly field personnel, make decisions on existing pipelines, when exposed for any purpose, as to whether any corroded region may be left in service or whether it needs to be
repaired or replaced. Such detenninations must be based upon sound research and extensive testing in order to provide safe and conservative guidelines on which to base field
decisions. The Manual provides procedures to assist in this determination.
Parts 2, 3, and 4 are based on Appendices G-6, G-7, and 0-8 of the ASME Guide for
Gas Transmission and Distribution Piping Systems, 1983 Edition. They are included in
this Manual for use by field operators to. determine the remaining strength of corroded
pipe. The technology is based on research done in the Columbus laboratories of the
Battelle Memorial Institute; specifically, their report Summary of Research to Detennine
the Strength of Corroded Areas in Line Pipe, July 10, 1971.
A revision to the 1984 edition of the Manual was undertaken in 1989. The revision
includes a number of clarifications and corrections. The computer program presented in
Appendix B and used to produce a printed table of maximum acceptable corrosion
lengths for a given pipe diameter, and up to ten wall thicknesses of that diameter, was
upgraded.
This Manual was approved by ASME and subsequently by the American National
Standards Institute on May 20, 1991.

iii

ASME CODE FOR PRESSURE PIPING, 831

OFFICERS
R. E. feigel, Chairman
l. E. Hayden, Jr., Vice Chairman
C. J. Gomez, Secretary

COMMIITEE PERSONNEL
P. A. Bourquin, Wolff & Munier International, Hawthorne, New York
A. J. Breugelmans, lvndhurst, New Jersey
J. D. Byers, Mobil Research & Development, Princeton, New Jersey
J. J. Chappell, Anchor/Darling Valve Co., Williamsport, Pennsylvania·
L. F. Clynch, CONOCO Mid-Continental Division, Ponca City, Oklahoma
P. C. DuPerneli. Lancaster, New York
R. E. Feigel, Hartford Steam Boiler Inspection and Insurance Co., Hartford, Connecticut
D. M. Fischer, Sargent & lundy, Chicago, illinois
P. D. Flenner, Consumers Power Co., Jackson, Michigan
P. H. Gardner, Hercules Inc., Wilmington, Delaware
R. W. Haupt, Pressure Piping Engrg Associates Inc., Foster City, California
L E. Hayden, Jr., Victaulic Company of America, Easton, Pennsyivania
R. R. Hoffmann, Federal Energy Regulatory Commission, Washington, DC
B. P. Holbrook, Riley Stoker Corp., Worchester, Massachusetts
H. M. Howarth, Trenton, New Jersey
W. B. McGehee, Spring, Texas
A. J. Shoup, Sr., Houston, Texas
G. W. Spohn. III, Dixie Constructors, Inc., Gaffney, South Carolina
H. A. Sosnin, Jenkintown, Pennsylvania
D. H. Wade, Texas Utilities Electric Co., Dallas, Texas

B31.8 GAS TRANSMISSION AND DISTRIBUTION PIPING SYSTEMS SECTION
COMMIITEE
A. J. Shoup, Sr., Chairman, Houston, Texas
W. B. McGehee, Vice Chairman, Spring, Texas
C. J. Gomez, Secretary, ASME, New York, New York
W. C. Alexander, Shreveport, louisiana
R. J. T. Appleby, Exxon Co., USA Thousand Oaks, California
J. E. Beech, Texas Gas Transmission Corp., Owensboro, Kentucky
C. Boshuizen, T. D. Williamson Inc., Tulsa, Oklahoma
L. E. Brooks, Delta Gulf Corp., Shreveport, Louisiana
F. E. Buck, Grove Valve & Regulator Co" Oakland, California
J. S. Chin, ANR Pipeline Co., Detroit, Michigan
W. L. Clayton, Entex Inc., Houston, Texas
P. J. Cory, Bowie, Maryland

iv

R. l. Dean. ConReg Associates. Bellaire, Texas
A. J. Del Buono, CMI·Princeton Inc., Princeton. Kentucky
P. W. Denning, Texas Gas Transmission Corp., Owensboro, Kentucky
M. J. Epperson, Texaco Inc., Bellaire, Texas
J. J. Fallon, Jr., Public Service Electric & Gas Co., Newark, New Jersey
F. R. Fleet, Natural Gas Pipeline Company of America, lombard, Illinois
M. A. Francis, llV Steel Tubular Products Co., Youngstown. Ohio
P. R. Goodholm~ Visalia. California
J. E. Hansford, fnron Gas Pipeline Operating Co., Houston, Texas
D. J. Hicks, Endeco Engineering Consultants, Tulsa, Oklahoma
D. T. Hisey, AReO Transportation Alaska. Anchorage, Alaska
M. C. Hocking, Transcontinental Gas Pipe line, Houston, Texas
E. A. Jonas, Bethlehem, Pennsylvania
J. J. Kieffer, Union Carbide Corp., Tonawanda, New York
J. D. McNorgan, Southern California Gas Co., los Angeles, California
A. I. Macdonald, Upland. California
R. E. Miller, Columbia Gas Systems Service Corp., Columbus, Ohio
R. A. Mueller, OXY USA Inc., Tulsa, Oklahoma
P. O. Mullens; Phillips Petroleum Co., Bartesville, Oklahoma
D. L Price, Texas Eastern Gas Pipe line Co., Harrisburg, Pennsylvania
W. F. Quinn, EI Paso Natural Gas Co., EI Paso, Texas
A. T. Richardson, Tenneco Gas Transportation Co., Houston, Texas
C. G. Roberts, Williams Brothers Engineering Co., Tulsa, Oklahoma
R. A. Schmidt, ladish Co., Russelville, Arkansas
B. Taksa, Gulf Interstate Engineering, Houston, Texas
C. J. Tateosian, Walnut Creek, California
A. T. Tyler, Gulf Interstate Engineering Co., Houston, Texas
H. M. WiUdnson, Houston, Texas
G. J. Wolf, Office of p'ipeline Safety, U. S. Department of Transportation, Washington, District of
Columbia
R. A. Wolf, Transok Inc., Tulsa, Oklahoma
J. M. Wood, Oklahoma Natural Gas Co., Tulsa, Oklahoma
D. W. Wright, Sun Pipe line Co., Tulsa, Oklahoma
C. C. Wright, Jr., Paola, Kansas
J. S. Zurcher, Panhandle Eastern Pipe Une Co., Houston, Texas

B31 COORDINATING COMMITTEE
D. M. Fischer, Chairman, Sargent & lundy, Chicago, Illinois
C. J. Gomez. Secretary, ASME, New York, New York
L. E. Hayden, Jr., Victaulic Company of America, Easton, Pennsylvania
R. R. Hoffmann, Federal Energy Regulatory Commission, Washington, District of Columbia
H. A. Sosnin, Jenkintown, Pennsylvania

831 FABRICATION AND EXAMINATION TECHNICAL COMMITTEE
P. D. Flenner, Chairman, Consumers Power Co., Jackson, Michigan
C. J. Gomez, Secretary, ASME, New York, New York
P. C. DuPernell, lancaster, New York
T. E. Estilow, Newark, Delaware
L E. Hartsell, Fluor Daniel. Dallas, Texas
. D. G. Hopkins. E I duPont de Nemours & Co.• Newark, Delaware
A. D. Nance, Evans, Georgia
R. I. Seals, Berkeley, California
H. A. Sosnin, Jenkintown, Pennsylvania

v

B31 MECHANICAL DESIGN COMMITTEE
R. W. Haupt, Chairman, Pressure Piping Engrg Associates Inc., Foster City, California
C. J. Gomez, Secretary, ASME, New York, New York
J. P. Breen, O'Donnell & Associates Inc., Pittsburgh, Pennsylvania
A. C. Dzykewicz, Bristol, Rhode Island
J. A. Graziano, Farragut, Tennessee
B. P. Holbrook, Riley Stoker Corp., Worcester, Massachusetts
W. J. Koves, UOP Inc., Des Plaines, Illinois
P. L. Lin, Fluor Engineers Inc., Chicago, Illinois
T. Q. McCawley, Charlotte, North Carolina
E. Michalopoulos, Hartford Steam Boiler Inspection and Insurance Co., Hartford, Connecticut
J. C. Minichiello, ABB Impel! Corp., Lincolnshire, Illinois
A. D. Nance, Evans, Georgia
T. W. Pickel, Jr., Martin Marietta Energy Systems Inc., Oak Ridge, Tennessee
E. C. Reed, Babcock & Wilcox Co., Barberton, Ohio
Q. N. Truong, Houston, Texas
. G. E. Woods, Kingwood, Texas

831 CONFERENCE GROUP
M. E. Bajandas, Department of Labor & Human Resources, Hato Ray, Puerto Rico
R. Beaucamp, Department of Labor, Lincoln, Nebraska
J. E. Brennan, Division of Boiler Inspection, Columbus, Ohio
W. E. Brown, State of Kansas, Shawnee Mission, Kansas
G. Bynog, Texas Department of Labor & Standards, Austin, Texas
R. Coomes, Department of Housing, Buildings, arid Construction, Frankfort, Kentucky.
Z. C. Cordero, Michigan Department of Labor, Lansing, Michigan
J. C. Cvar, Division of Boiler Safety, Dover, Delaware
A. W. Diamond, Department of Labour & Manpower, St. Johns, Newfoundland, Canada
M. P. Fitzpatrick, Department of Labour & Human Resources, Fredericton, New Brunswick, Canada
J. W. Greenawalt, Jr., Oklahoma Department of Labor, Oklahoma City. Oklahoma
G. Grodecki, Ministry of Consumer & Commercial Relations, Toronto, Ontario, Canada
R. D. Herman, Saskatchewan Labour, Regina, Saskatchewan, Canada
D. W. Johansen, Public Service Commission, Jefferson City, Missouri
A. Justin, State of Minnesota, Saint Paul, Minnesota
J. T. Little, Industrial Commission of Arizona, Phoenix, Arizona
W. T. Malloy, Washington Utililies & Transportation Commission, Olympia, Washington
R. G. Marini, New Hampshire Public Utilities CommiSSion, Concord, New Hampshire
I. W. Mault, Labour & Manpower, Winnipeg, Manitoba, Canada
A. W. Meiring, Department of Fire Prevention & Building Safety, IndianapOlis, Indiana
E. E. Morgan, Boiler Inspection Section, Denver, Colorado
J. W. Morvant, Office of State Fire Marshal, Baton Rouge, Louisiana
R. F. Mullaney, Boifer & Pressure Vessel Safety Branch, Vancouver, British Columbia, Canada
W. A. Owen, North Dakota Public Service Commission, Bismarck, North Dakota
W. M. Picardo, Department of Consumer & Regulatory Affairs, Washington, District of Columbia
R. Sauve, Government of Quebec, Montreal, Quebec, Canada
P. Sher, Department of Public Utility Control, New Britain, Connecticut
H. E. Shutt, Illinois Commerce Commission, Springfield, Illinois
J. L. Smith, Alberta Department of Labour, Edmonton, Alberta. Canada
R. L.. Smith, Public Service Commission, Columbia, South Carolina
M. L Snow, Jr., Department of Commerce and Insurance, Nashville, Tennessee
E. l. Sparrow, Bureau of Pipeline Safety, Newark, New Jersey
D. Stursma, Iowa State Commerce Commission, Des Moines, Iowa
R. P. Sullivan, Department of Labor, Augusta, Maine
C. W. Thompson, Department of Labor, Little Rock, Arkansas

vi

R. W. Vindich, Department of labor & Industry, Harrisburgh, Pennsylvania
l. E. Waldrop, Public Service Commission, Montgomery, Alabama
C. H. Walters, Boiler & Elevator Programs, Portland, Oregon
M. W. A. West, Department of Fisheries & labour, Charlottetown, Prince Edward Island, Canada
T. F. Wickham, Department of labor, Providence, Rhode Island
R. A. Yeo, Department of labour and Manpower, Halifax, Nova Scotia, Canada

831 NATIONAL INTEREST REVIEW GROUP
Aluminum Association - W. W. Pritsky
American Boiler Manufacturers Association - R. J. Fletcher
American Institute of Chemical Engineers - W. C. Carnell
American Iron and Steel Institute - J. R. Pegues
American Petroleum Institute. Division of Refining - H. M. Howarth
American Pipe Fitting Association - J. Thielsch
American Society of Heating, Refrigeration & Air Conditioning Engineers - H. R. Kornblum
American Welding Society - H. A. Sosnin
Chemical Manufacturers Association - D. R. Frikken
Compressed Gas Association - M. F. Melchioris
Copper Development Association - A. Cohn
Ductile Iron Pipe Research Association - T. F. Stroud
Edison Electric Institute - R. l. Williams
International District Heating Association - G. Von Bargen
Manufacturers Standardization Society of the Valve and Fittings Industry - R. A. Schmidt
Mechanical Contractors Association of America - W. E. Maloney
National Association of Plumbing-Heating-Cooling Contractors - R. E•. White
National Association of Regulatory Utility Commissioners - D. W. Snyder
National Fire Protection Association - T. C. lemoff
National Fluid Power Association - H. Anderson
Naval Sea Systems Command - T. W. Hull
Pipe Fabrication Institute - l. Katz
Slurry Transport Association - P. E. Snoak
Society of Ohio Safety Engineers - J. M. Holleran
Valve Manufacturers Association - R. A. Handschumacher

vii

CONTENTS

Foreword ...............................................................................
Personnel ......................... ~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

iii
iv

Part 1

Introduction ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .. . . . . .

1

1.1

Scope..............................................................

1

1.2

Limitations ........................................................
Initial Development ..............................................
Methodology and Research Procedures .........................
How to Use the Manual ......... . . . . . . . .. . .. . . . . . . . . . . . . . . . .. . ..
The Meaning of Acceptance ......................................
Other Means of Determining Safe Pipeline
Operating Pressure ....................... . . . . . . . . . . . . . . . . . . . . .
Computer Programs ..............................................

1
2
2
3

1.3
1.4
1.5
1.6
1.7

1.8
Figures
Fig. 1-1

5
5
5

Parabolic Criteria for Classifying Corrosion
Defects According to Predicted Failure Stress ...............

4

Procedure for Analysis of Corroded Pipe
Strength ........................................................

6

Determination of Maximum Allowable
Longitudinal Extent of Corrosion...... . .. . . . . . . . . . . .. . . . . . ..

9

Figures
Fig. 2-1
Fig. 2-2

Corrosion Parameters Used in Analysis.........................
Curve for Determining the Value of B ................ ..........

10
11

Part 3

Tables for Corrosion Limits .. ~....... .. .................. ..... .

13

Fig. 1-2

Part 2

Tables
Table 3-1

Table 3-2

Values
and
Values
and

of L for Pipe Sizes ~ NPS 2
< NPS 6 ..................................................
of L for Pipe Sizes ~ NPS 6
< NPS 10 ................................................
viii

14
15

Table 3-3
Table 3-4
Table 3-5
Table 3-6
Table 3-7
Table 3-8
Table 3-9
Table 3-10
Table 3-11
Table 3-12

Part 4
4.1
4.2
4.3
Figures
Fig. 4-1

Fig. 4-2

Appendices
Appendix A

Appendix B

Values
and
Values
and
Values
and
Values
and
Values
and
Values
and
Values
and
Values
and
Values
and
Values
and

of L for Pipe Sizes ~ NPS 10
< NPS 16 ................................................
of L for Pipe Sizes ~ NPS 16
< NPS 20 ................................................
of L for Pipe Sizes ~ NPS 20
< NPS 24 ................................................
of L ~or Pipe Sizes ?: NPS 24
< NPS 30 ................................................
of L for Pipe Sizes ~ NPS 30
< NPS 36 ................................................
of L for Pipe Sizes ~ NPS 36
< NPS 42 ................................................
of L for Pipe Sizes ~ NPS 42
< NPS 48 .................................•..............
of L for Pipe Sizes ~ NPS 48
< NPS 52 ................................................
of L for Pipe Sizes ~ NPS 52
< NPS 56 ................................................
of L for Pipe Sizes ~ NPS 56
< NPS 60 ................................................

16
17

18
19
20

21
22
26
30
34

Evaluation of MAOP in Corroded Area ....................... 39
Computation of A ......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. _ 39
Computation of P' ................................................ 39
MAOP and pi .....................
42
a.a. •••••••••••••••••••••••••••

Curve for Obtaining P as a Function of d/t for
Values of A Less Than or Equal to 4.0 .......................
P I as a Function of dlt for Values of A Greater
Than 4.0 .. , ... ...... ....... .... ....... ..........................
I

BASIC Computer Program, CRVL.BAS, for
Determining Allowable Length L (Part 2) or
Alternative Maximum Allowable Operating
Pressure (Part 4) ...............................................
BASIC Computer Program, CRLGTHU.BAS,
Used in Generating Tables Like Those Which
Are Printed in Part 3 ..........................................

ix

40
41

43

51

This page intentionally left blank.

1.1-1.2

ASME B31G-1991

PART 1
INTRODUCTION

1.1 SCOPE

The scope of this Manual includes all pipelines within the scope of the pipe!ine codes
that are part of ASME B31 Code for Pressure Piping, i.e., ASME B31.4, Liquid Transportation Systems for Hydrocarbons, Liquid Petroleum Gas, Anhydrous Ammonia, and
Alcohols; ASME B31.8, Gas Transmission and Distribution Piping Systems; and ASME
B31.11, Slurry Transportation Piping Systems. Parts 2, 3, and 4 are based on material
included in ASME Guide for Gas Transmission and Distribution Piping Systems, 1983
Edition.
This Manual is not applicable to new construction covered under the B31 Code Sec·
tions. That is, it is not intended that this Manual be used to establish acceptance standards
for pipe that, may have become corroded prior to or during fabrication andlor installation.
This Manual is intended solely for the purpose of providing guideline information for
the designer/owner/operator. Thus, the specific use of this Manual is the responsibility
of the designer/owner/operator.

1.2 LIMITATIONS
(a) This Manual is limited to corrosion on weldable pipeline steels categorized as
carbon steels or high strength low alloy steels. Typical of these materials are those described in ASTM A 53, A 106, and A 381, and API SL. (The current API SL includes
all Grades formerly in API 5LX and 5LS.)
(b) This Manual applies only to defects in the body of line pipe which have relatively
smooth contours and cause low stress concentration (e.g., electrolytic or galvanic corrosion, loss of wall thickness 'due to erosion).
(c) This procedure should not be used to evaluate the remaining strength of corroded
girth or longitudinal welds or related heat affected zones, defects caused by mechanical
damage, such as gouges and grooves, and defects introduced during pipe or plate manufacture, such as seams, laps, rolled ends, scabs, or slivers.
(d) The criteria for corroded pipe to remain in service presented in this Manual are
based only upon the ability of the pipe to maintain structural integrity under internal
pressure~ It should not be the sole criterion when the pipe is subject to significant secondary stresses (e.g., bending), particularly if the corrosion has a significant transverse
component.
(e) This procedure does not predict leaks or rupture failures.

1

1.3-1.4

ASME B31G-1991

1.3 INITIAL DEVELOPMENT

In the late 1960s, a major long-lines gas transmission pipeline company in conjunction
with the Battelle Memorial Institute in Columbus, Ohio 7 began a research effort to
examine the fracture initiation behavior of various kinds of corrosion defects in line pipe.
This included determining the relationship between the size of a defect and the level of
internal pressure that would cause the defect to -leak or rupture. The testing by the gas
pipeline company and Battelle demonstrated that there was indeed a possibility of developing methodology and procedures to analyze varying degrees of corrosion of existing
pipelines. From this, an operator could make a valid determination as to whether the
pipelines could safely remain in seIVice or should be repaired or replaced. As the awareness of this research program grew, other transmission companies began to express considerable interest.
Beginning in the early 1970s, the American Gas Association (AGA) Pipeline Research
Committee assumed responsibility for this activity and began developing methods for
predicting the pressure strength of line pipe containing various sizes of corrosion defects.
The overall objective of these experiments was to examine the fracture initiation behavior of various sizes of corrosion defects by determining the relationship between the
size of a defect (ll!d the level of internal pressure that would cause a leak or rupture.

1.4 METHODOLOGY A~D RESEARCH PROCEDURES

The procedure contained in this Manual is based upon pressuring actual corroded pipe
to failure in an extensive series of full-size tests. Since there was pipe available that had
been removed from service and that had sustained corrosion damage, it, seemed more
logical to test these full-size) actual field specimens, either in place or in a large, fullscale test cell, rather than base these guidelines upon purely laboratory tests using machined defects. Several hundred fun-scale pipe tests were conducted on all types of
defects to establish general defect behavior. Mathematical expressions to calculate the
pressure strength of corroded pipe materials were developed on the basis of these extensive tests. These mathematical expressions, although semiempirical, were founded
upon well established principles of fracture mechanics. The basis principle of fracture
mechanics is that the resistance of the material to unstable fracturing in the presence of
a defect is related to the size of the defect and an inherent metal property called toughness. The tougher the material, the larger the flaw that can be tolerated before failure
will occur. Also, the bigger the defect, the lower the pressure at which a leak or rupture
will occur. These two features may seem obvious, but they form the basis of fracture
mechanics in terms of detennining the real strength of pipe containing defects.
During 1970 and 1971, 47 pressure tests were conducted on several pipe sizes to
evaluate the effectiveness of the mathematical expressions in determining the strength
of corroded areas. The diameter of the pipe material examined ranged from 16 in.
through 30 in. 'and wall thickness varied from 0.312 in. through 0.375 in. The pipe materials have ranged in yield strength from about 25,000 psi for API 5L Grade A-25 to
about 52,000 psi for 5LX Grade X-52.
The mathematical expressions developed from the earlier experiments have been modified based on later test results and now provide reliable estimates of the failure pressures
for corrosion defects over the range of materials covered in this study. The experiments

2

Copyright© 1991 by the Aillerican Society of Mechanical Engineers,
No reproduction may be made of this material \vithout written consent of ASME.

~

~

1.4-1.5

ASME B31G-1991

on corroded pipe indicated that line pipe steels have adequate toughness and that the
toughness is not a significant factor. The failure of blunt corrosion flaws is controlled by
their size and the flow stress or yield stress· of the material.
Figure 1-1 shows the relationship between the full-size test failures and the criterion
for acceptance of corrosion pits in line pipe. The criterion is that they shall withstand a
pressure equal to a stress level of 100% of the specified minimum yield stress (SMYS).
The Figure is based on an assured parabolic profile of the corroded regions and presents
the maximum corrosion depth, divided by the pipe wall thickness, plotted against the
corrosion length, divided. by the square root of the pipe radius times wan thickness. Each
of the data points plotted represents one full-size pipe experiment on corroded pipe, and
the number next to the data point represents the stress at failure pressure expressed as
percent SMYS. There are only 3 data points (experiments) that failed at pressure levels
below 100% SMYS, indicating the lack of severity of corrosion defects in general (note
that all three would be rejected by this criterion). The solid line shown on the Figure is
the line that identifies failure pressures of less than 100% SMYS. There are a number
of data points that are below this line, but all of them represent failures above 100%
SMYS. The fact that these are above 100% SMYS simply indicates that the criterion is
very conservative.
The acceptable region in the plot is the shaded region below and to the left of the
solid line. The Tables in Part 3 are based on corrosion depths and lengths determined
by this solid line. Corrosion pits that have depths and lengths that fall above the CUlVe
are not acceptable, in accordance with the criteria presented herein, and the operating
pressure either has to be reduced, or the corrosion pit r~moved or repaired.

1.5 HOW TO USE THE MANUAL
Part 2, Determination of Maximum Allowable Longitudinal Extent of Corrosion, sets
forth the equations for determining the severity of the corroded areas. It tells the operator
how to measure the longitudinal extent and maximum depth of the corroded areas. One
can then use Eq. (2) of Part 2 to determine if the corroded area is serious.
However, it is recognized that most field operators will prefer a simpler method of
evaluating a corroded area. Therefore, Part 3, Tables for Corrosion Limits, evaluates Eq.
(2) and places the results in tabular fonn. This allows the field operator to make decisions
simply by going to a table after measuring the longitudinal extent and maximum depth
of the corroded area and making a choice.
Locate the table appropriate for the pipe O.D. and wall thickness. Look down the left
column and find the depth of corrosion that is equal to or the next number larger than
the measured maximum depth of the corroded area. Read across to the column headed
by the wall thickness or next number lower than the pipe's nominal wall thickness to
determine the maximum allowable longitudinal extent of the corroded area for the depth
of corrosion. If the measured longitudinal extent of the corroded area is equal to or less
than the maximum allowable longitudinal extent of the corroded area determined from
the Table, the pipe strength is suitable for the present MAOp I and is capable of containing a test pressure that win produce a stress of 100% SMYS of the pipe material.
1

As used in this manual, the term MAOP shall represent maximum steady state operating pressure for pipelines

within the scope of ASME B31.4 and ASME B31.11 and maximum allowable operating pressure for pipelines
within the scope of ASME B31.8.

3

1.0

,..-----;.

134



......

~~~~

~
"t)

0.8

~
c

~

::::::::: 133:. .

::::::::::.:.:.:.:.::::.
.:.:.:.:.: '36. . .

(J

:c....
"iij

~

0.6

IV

0.

:e..s:

• 107. 133\106
.117. • .113 /
.'30
12..95"
• 111
~1i1

~~:~:f~:~:~:~:~~\~~·
126 •
·:·:·:-:·········:.-:·.·.·.::::\.·139 137 _

.105

• 128
122



...0

132

• 198
·170

132

·209
Numbers adjacent to data points are
failure pressures expressed in
terms of % SMYS

c
0

...
I

........---~

153



• 155

-!

'Iii

.......

• • 202

Q.

+:roo

...... .....

1~



139

:::::;::=::::::::'
~:~{f:::::::~:

.;

......
84

182

90

1ff\'

.- --- - -- ----

.."

<?'

0.4

• 142

(5
(J

E
:::I
E

'X
«I

:?!

100% SMYS

0.2

o

2

3

4

5

6

Corrosion length/ (pipe radius X wall thickness) 1/2, L /~

7

8

z;;

s:

m

m

w

FIG. ,.,

PARABOLIC CRITERIA FOR CLASSIFYING CORROSION DEFECTS
ACCORDING TO PREDICTED
FAILURE STRESS
:

-'

~

(0

co

-'

1.5-1.8

ASME 831G-1991

The tables produce results which may be more conseIVative than Eq. (2) of Part 2.
The tables could show that the corroded area is unsuitable for the current MAOP, but
Eq. (2) may show that it is. Therefore, it is possible for the corroded region to be rejected
by the tables, but found suitable by using Eq. (2).
If the tables and Eq. (2) both show the corroded region to be unsuitabe, it may still
be possible to establish suitability by one of the methods mentioned in para. 1.7. Another
alternative would be to lower the MAOP of the pipeline, if permitted by operating
conditions. Part 4 can be used to determine a lower MAOP that has the same safety
factor provided by Parts 2 and 3.
Regardless of which alternative is chosen, in all cases where the corroded region is to
be left in service, 'measures should be taken to arrest further corrosion. Such measures
should include coating the corroded region and, if indicated, increasing the cathodic
protection level.
Figure 1-2 , Procedure for Analysis of Corroded Pipe Strength, shows the steps necessary to proceed through the evaluation of a corroded area on a pipeline in order to
determine if any corrective action is needed. The steps shown in the dashed boxes are
valid means of determining a safe operating pressure (or MAOP), but the procedures
for conducting these steps or the acceptance levels are not in this Manual.

1.6 THE MEANING OF ACCEPTANCE
(a) Any corroded region indicated as acceptable by the criteria of this Manual for

service at the established MAOP is capable of withstanding a hydrostatic pressure test
that will produce a stress of 100% of the pipe SMYS.
(b) Any corroded region indicated as acceptable for service at a reduced MAOP is
capable of withstanding a hydrostatic pressure test at a ratio above the MAOP equal to
the ratio of a 100% SMYS test to 72% SMYS operation (1.39:1). If a larger ratio is
desired, the reduced MAOP can be adjusted accordingly.

1.7 OTHER MEANS OF DETERMINING SAFE PIPELINE OPERATING PRESSURE
(a) The operator can make a more rigorous analysis of the corroded area to determine
the remaining strength by performing a fracture mechanics analysis based upon established principles and practices using the actual profile of the corroded region.
(b) The operator can reestablish the MAOP by a complete hydrostatic pressure test
. that produces a minimum stress of 100% SMYS, or establish a lower MAOP based on
the pressure of a successful 'test conducted at a lower pressure.
(e) The procedures and acceptance criteria for conducting these alternative acceptance tests, either fracture mechanics analysis or hydrostatic tests, are not included in this
Manual.

1.8 'COMPUTER PROGRAMS

Appendix A is a BASIC computer program, CRVL.BAS, developed by Mr. Richard
L. Seifert and is based on the equations in Parts 2 and 4. It can be used to expedite the
evaluation procedure. Several examples of the program output are shown.
5

ASME B31G-1991

Measure maximum
Greater 1 4 - - - - - - - . . . . . . . depth of corroded area
than 80%
and compare to nominal

10%
or less

wall thickness

t

I

I

Between
10 and 80%

i

Measure
length
longitudinal
greater
extent of the
than value ... corroded area
from
and compare to
appropriate
the value from
table
appropriate

it-

table Part 3

Length
equal to or
less than
value from
appropriate
table

f
Part 2
compare MAOP

..

to maximum
pressure P'
calculated
from equation

-

,

MAOP

same or
smaller

r------,
I

MAOP

larger

Option to perform I Pass
'more rigorous fracture I
::mechanics analysis I

-----Repair or

replace

Reduce

......

Choice

Part 4

r - . . -1

I

L ___ JJ

L ____ -'I

I

Pressure
test

r----.I

..- -..
..,...

FIG. 1·2

-

MAOP

....

Confirm or
reduce MAOP
based on test

i-+

...

Arrest
further
corrosion
and return
to service

PROCEDURE fOR ANALYSIS OF CORRODED PIPE STRENGTH

6

1.8

ASME B31G-1991

Appendix B is a BASIC computer program, CRLG1HU.BAS by Mr. Seifert, which is

an upgrade of CRLGTH.BAS, which was contained in the first printing of this Manual.
CRLGTH.BAS was used to produce some of the tables in Part 3. It required that the
BASIC program be modified slightly each time it was used. The new program
CRLGTIIU.BAS does not require modification. It will produce a printed table of maximum acceptable corrosion lengths for a given pipe diameter, and up to ten wall thicknesses of that diameter. An example of a printed table by this program is included at
the end of Appendix B.
Both CRVL.BAS and CRLGTHU.BAS were written in BASIC for a specific computerl
printer combination and can be utilized by most state-of- the-art microprocessors. However, minor modifications may be necessary for use on other equipment or for other
purposes.
These computer programs are reproduced herein solely for the convenience of the
Manual user, and ASME and the auther make no claims as to their accuracy or effectiveness.

7

Part 2

ASME B31G-1991

PART 2

DETERMINATION OF MAXIMUM ALLOWABLE
LONGITUDINAL. EXTENT OF CORROSION

The depth of a corrosion pit may be expressed as a percent of the nominal wall
thickness of the pipe by:
% pit depth

=

(1)

100d/t

where

d = measured maximum depth of the corroded area, in., as shown in Fig.

2~ 1

t = nominal wall thickness of the pipe, in. Additional wall thickness required for

concurrent external loads shaH not be included in the calculations.
A contiguous corroded area having a maximum depth of more than 10% but less than
80% of the nominal wall thickness of the pipe should not extend along the longitudinal
axis of the pipe for a distance greater than that calculated from:

L = 1.12BVDt

~

(2)

(L may also be determined from Tables 3-1 through 3-12 in Part 3.)
where
L = maximum allowable longitudinal extent of the corroded area, in., collinear with
LM in Fig. 2-1
D = nominal outside diameter of the pipe, in.
B = a value which may be determined from the curve in Fig. 2-2 or from:

y(

)2

B d/t
- 1
(3)
1.1 d/t - 0.15
except that B may not exceed the value 4. If the corrosion depth is between 10%
and 17.5%, use B = 4.0 in Eq. (2).

9

Fig. 2-1

ASME B31G-1991

longitudinal axis of pipe

t---LM! Measured longitudinal extent of the

1/

corroded area

Measured

maximum depth of corros~~~

~ffi'22z7Z7/;W-t
FIG. 2.. '

CORROSION PARAMETERS USED IN ANALYSIS

10

ASME 831 G·1991

Fig. 2-2

,

8=4

4

V ~ A l.ld/:~O.15 )2

3

-1

/

B

~

2

\,

\..

o

0.2

~

~~

0.4

0.6

............

0.8

dlt

FIG. 2·2

CURVE FOR DETERMINING THE VALUE B

11

Part 3

ASME B31G-1991

PART 3

TABLES FOR CORROSION LIMITS

-The tables in -this Part are calculated from the equations in Part 2. They provide a
ready reference of maximum corrosion lengths for a spectrum of pipe diameters, wall
thicknesses, and pit depths. These Tables may be used to determine the maximum allowable longitudinal extent of a contiguous area of corrosion as given in Part 2.
(a) The corroded area must be clean to bare metal. Care should be taken when cleaning corroded areas of a pressurized pipeline.
(b) Measure the maximum depth of the corroded area d and the longitudinal extent
of the corroded area as shown in Fig. 2-1.
(e) Determine the size (NPS) of the pipe and nominal wall thickness.
(d) Turn to the page in the Table corresponding to the size (NPS) of the pipe.
(e) Locate the row showing a depth equal to the measured maximum depth of the
corroded area. If the exact measured value is not listed, choose the row showing the
NEXT GREATER DEPTH.
(f) Scan across to the column showing the waIl thickness of the pipe. If the nominal
wall thickness is not listed, use the column for the NEXT THINNER WALL. The value
L found at the intersection of the wall thickness column and depth row is the maximum
allowable longitudinal extent of such a corroded area.
(g) The tables in Part 3 produce results which may be more conselVative than those
obtained from the equations in Part 2. Therefore, the tables could show that a given
corroded area is unsuitable for the current MAOP, but the use of the equations in Part
2 may show that it is acceptable.

13

Table 3·1

ASME B31G-1991

TABLE 3-1

VALUES Of L FOR PIPE SIZES ~ NPS 2 AND < NPS 6

Depth,
d, in.

0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.10
0.11
0.12
0.13
0.14
0.15

-Wall Thickness, t, in.
0.083

0.109

0.125

0.141

0.154

115/u.

2'116

211/U.

%

2 7/lf.
1%

1%

%

%

-1/..

15A,

115116
1%

5/16

7/11..

9116

n/u•

ll/U.

0.172

0.188

0.218

2
15/1f•

%

1/4

2%
2%

3
3

1%

Pf4

1

13116

3 1/4
2lJ4
1%

%

%

'-'/lf.

'1ft6

HIli.

15/16

5/16

7/16

9fl6

"/H.

3/4

sit,

%
%6

lh
7/"

'fa

13/u.

7/11'.

'.lA,
112

11/16

J4

9/16

%

1/4

-%,

%

7/16

%

11/\6

Stu.

lla

7A,
%

1/1

%

7,'1,

%.

SA6

-%

%

%

7/11•

S/lI>_

71i6

5f,6

13/16
1~

1/,

0.16
0.17

%

14

Table 3-2

ASME B31G-1991 .

TABLE 3-2
Depth,
d, in.

0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
0.110
0.120
0.130
0.140
0.150

VALUES OF L fOR PIPE SIZES ~ NPS 8 AND < NPS 10

Wall ThickneSs, t, in.
0.083

0.188

0.203

0.219

0.250

0.312

5
2 15h6
11Sfu.

53h6
3%
2 5/"

5%

5 3/ ..
51/ ..
3%

67/16
61/16

19/1(,

PI..
17/,6

211".

lIJ4

17/16

1%
1

P/..
1%

0.125

0.156

4IJt6

4'/1(,
3%
11fa
1%

5

H~

3 5/16

1'12
1fa
%

F4
1'/4

%

ISh,

'/'6

13/16

4%

2

3
/.

1'1/1(.

2 11/16
2 '1a
PI..

4 1/4

Hh6

IS/I(.

Ph6

'/16

V.z

1l/'6
3/4

1'4
1

7/H•

Ilh.

%

9h.

niH.
l/.c

71a

1%

P/.

I31t6

'Vu.

llf8

ll/H. '

%

74

%

"/, ..

B/H;

l1f'6
'V'6

1%
17/,6

91t6

%

314

%

1'1.

9/16

Ifh"

H/16

%

%

13/16
1%

3/..

11/,6

'IH,

0.160
0.170
0.180
0.190
0.200

3%

1'/1(,

211/11;
2'1..

Pia

2

1%

Il/u.

%

0.210
0.220
0.230
0.240

15
/16

'hi

'YI6
1l/1f>

3/4

15

ASME 831G·1991

Table 3-3

TABLE 3·3
Depth,
d, in.
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
0.110
0.120
0.130
0.140
0.150
0.160
0.170
0.180
0.190
0.200
0.210
0.220
0.230
0.240
0.250
0.260

0.156

VALUES OF L FOR PIPE SIZES

~

NPS 10 AND < NPS 16

Wall Thickness, t, in.
0.307
0.344

0.219

0.250

6 7/8

7 31a
7%

8'/a

8%

8%

4 1S/16

8%

8%

0.438

0.500

8%

9%

10%

8'/.

911.

1011a

0.365

513A6
4%6

15
/16

2%6
P;"

5
31h

1711(.

2'/16

3%

5 1/ ..

8%

t 3/16

21/a

4%
3 5116
2 13/16

6%

93f..

10%

111/16

2'lfu.
2 1/J.
115/1(,

5%

11/16

4%

8%
6%

10318

IS/u•

P/H;

13A6

17/16
13/16

P/4

21116

4 3/1f.
3%
3

1'A6

2lJ1(,

2%

llfl6

7A6

15/H.
llf4

2
113/l(.
1"/,6

1%
1'/1(,

19/16
17/u.

%
11/11•

ls/H.

%
°/16

1

3/.
7At

1%
1 5/ 16
1%

13/H;

1%

15
/16

3 ,sA6
3%
2 1S/H.

4 15/1£>

2%
23/16
2
Pia
1%

2%
2%
2 3/,6

3 1'/16
3 5/16
3
2 3/4

1%

1 /16

2 1A6
115/1(.

4%

9%
615/,6
5%
4 13/16
41/4

3 1lJ16

37/lf.

2'%6

33/16

2 15A6

P/'6

111/16

2%
2'1.

17/16
Pia

1%

2 118

21f..
2%

Ph

2

27/11:'

1%

1Sfu.

7

1 /16

FI8

2Sf)f.

n'l6

11/.

1 n /H.

11/'6

1%
1Sf,,;

111A6

15/16

0.270
0.280
0.290
0.300
0.310

13

Hil

1'/..

1'/16

13/16

19/16

2%
2 11a
21/1(.
115/16

1'/16

1Va

l ljz

1'/8

1'116

7

11,116

.. " ...

PI..

1 /u.
1 71,6
1%
15/16
1 '14
1 3/1(,

0.320
0.330
0.340
0.350
0.360

1%"
1%

11/16

l'V16

PI.

1"/16
1%
1'/16

1'12
17/u,
1%
1%
1sh6
1'I..

0.370
0.380
0.390
0.400
0.410

11/4

lYI6
PilI>

16

ASME B31G-1991

Table 3-4

TABLE 3-4
0.188

0.V20
0.030
0.040
0.050
0.060

7lf4
7%
4%
3 'Ji6
2%

0.070
0.080
0.090
0.100
0.1 to

2

0.120
0.130
0.140
0.150
0.160

Bois
1'/"

0.220
0.230
0.240
0.250
0.260

~

NPS 16 AND < NPS 20

Wall Thickness, t, in.

Depth.
d, in.

0.170
0.180
0.190
0.200
0.210

VALUES OF L FOR PIPE SIZES
0.250
••••

6
41f8

P/..

231.
2%

'fa

0.375

0.438

0.500

10'12

11
11

11%

11

11%

12'lf1(,
12 " /1(.

10
10
7'Ji6

5lJ4
4%.

10'12
10 112

6%
5%
4lJ..
3%
3'14

813/16

11%
l

6%
5lfu.
4 5A,
3 3/.

10 /'6
7'/'6
6
5%

2'Ia
t 15/16

3'/2
3'11(,
23/4

1%
Ph
t'll
1%
15A,

2'h
2%
2'h
1 1sJi.
l H /lt.

2 1511,

3%

4'12

2"A,

3V'6

2 7/H.

2 H I1,

2'/.
2%

2%

4
3%
3%
3%

3

1'1J16
1%
1%
FA6
Pia

2
Pia

1 /16
1%

1'/11.

15/"

1'/4
P/'6

2

7
/16

lH/u •

21f4
2%
2
l,s/IE,

2'Sjlf.
2%
29/16
2 7ft6

1%

lU/,6

25/16

P/..
1"1,6
l'/H.

3
/"

2

11,7

1'5/1(.

P/4

1'12
1'/1(,
Pia
15/ 16
1V..
13/16

0.270
0.280
0.290
0.300
0.310

2

~%

12tlJi6
12 /,6
"
11 7/"
8'12
6%

5%
53/1(,

14311,
14)111;
14%,
143/u.
13%

10'/,6
8%

4%

7 7/1f,

41J.
3%

69/H.
5 'S/16

3%
3%
3 3116
3
2%

5%
5
4%
4%

21lJi6
2 9/1(,

4'/3.

. 3%
-3 11/16

3'/Z

2'12
2%

3%

1'11,

Pia

2'/4

3'/..

Bois

11)/,6

15116

1 11/16

Ph6

1%
19/,6
1%6

23ft6
2%
2'/1(.
115/H,
FIB

3%
3
27111
21/ ..
2"/16

1'12

113/,&

2'/'6

1 7/1(,

PI.

1'/"

0.320
0.330
0.340
0.350
0.360

1%

l'Y'6

2%
27/1(,

PA6

1"h6

2%

1%

2V16

l~/u.

2%

1%
17/,6

2 3/16

0.370
0.380
0.390
0.400
0.410
0.420
0.430
0.440
0.450
0.460

0.625

0

815/H.

1'h
1%
1't.

/16

0.344

8 ,sA6

3%

15

0.312

7

1 /lf.

21~

2'/16

2
1,sAl>

.....
........
....

tIo

...

1%
1%
1Il/I &
P/..
l'lJi6

0.470
0.480
0.490
0.500

l

11
/H.

1%

19/'1>

0.510

17

Table 3-5

ASME B31G-1991

TABLE 3-5

VALUES OF L FOR PIPE SIZES ~ NPS 20 AND < NPS 24

0.219

0.250

0.344

0.030
0.040
0.050
0.060
0.070

9%
8 1A6
4%
39A,
2%

10
10
6 1l/lf>

4%

0.080
0.090
0.100
0.110
0.120

2 /1(.
2'/t6

1%

0.130
0.140
0.150
0.160
0.170

1%
1%
1'/4
13/J6
l 1/H.

0.180
0.190
0.200
0.210
0.220
0.230
0.240
0.250
0.260
0.270
0.280
0.290
0.300
0.310
0.320
0.330
0.340
0.350
0.360
0.370
0.380
0.390
0.400
0.410
0.420
0.430
0.440
0.450
0.460
0.470
0.480
0.490
0.500
0.510

~

Wall Thickness,

Depth,
d, in.

7

3 11/16

in.

0.406

0.469

0.500

1V/..

12:%

11%

12)/4
12%

13 3/ ..
13%

14:J/1(.

13lJ.

14)A6

7'116

8

lIs/if.

5 1111&
4%
4 5/1&

7 15116
6%
5 3/ ..

111/1&
111116

3
23/4

4%

l'/H.

2'A ..

3 15/16
3'Yu.
35/1&

FA6
1%

2%
2%

3 1/16

l1f4
13/'6

21fa

2 11/16

2

2'/'6

3 7/16
31/16

1'4
1 niH.
111f1'

2 7/16
2 5/1(.
23f16

1%
19/u,
l'h

214
2
115/16

,15/16

1%

2%

1%1

0.625

15
15

15 13116

14 A6
12 13A&
9%
7 11/16
6'/16

15
15
14'1b
10%
8 11A6

15 11116
15 13/1&
15 11/t&
15 th
1 PI.

53J..
53Ju,

7'/16
6'/lf.

4%
4l,1,
4 1/1(,

57/11
5 1,1,
4 IS/H,

9 11/t6
8 5ft 6
75flf.

1VA

5
4 3/.
4V16
3%
3'/..

3lfH.
211j16
ll,1,

0.562

3
/"

1
1%

7
/16

7,1,

6 13/16

2%

Fla

1%
111/11:.

13

3
/4

lOY"

51/16
4 3/H.

3%
3%

143A6

3

313h6

4%

4 5A6

31f16
2%
23f4"

39/16
3%
31/16
31f16

25/11
2%

5'1, ..
53,1,6

4 1/"
3%

4%

3%

4 5/H.

2%
2 3/.

3 112
3 sA6

2'/,6

2 1lA6

2Vl&
2lf4

29/H,

33/16
3 1116
2 1 5f1 ..

414
3 '51.6
VI..
3%
31/t,

2 7/u.

4'116

21/16

2%
29/16
2 7116

35/,..
33ft6
31fe
3
2 71a

2

2"%

2 13/16

P/4

liS/H.

2%;

2

PlJu.

Fia

21/4

2%

1%

113/,6

23/1~

29/"

19/16

P/4

2%

2112

ll 1h ..

2'/1&

2 7/u.

1%

2

2J,4

PIli.

115/11>

2 5111;

F/a
11)/16

21/4

13/4

2%
21/, ..

23/11

l'Y'6
Ph

2%
2'1u.
2
l'Vl6

2 3/'6
2%

17/16

Fla
lU/16

1%

6%
6 'Ar.

2%

2 11/16
23/4

P/4

1

14

23fl6

2
115/16
l's/u,

Fla
113fT&
P/~

Table 3-6

ASME B31G-1991

TABLE 3·6
Depth,
d, in.
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
0.110
0.120

VALUES OF L FOR PIPE SIZES ~ NPS 24 AND < NPS30

Wall Thickness, t, in.
0.250

0.312

0.375

12'14
121f..
9'h.
67h.

1VA.
13'/,6
13'h6

1'"1
75/"
5'1",
4
3%
2'5h.

2%
2%
2lfe

5%
4 5/,.

1%
1
3"

31h6

15
15
15

15'h
15'h
15'h

10l l/n.

161,'1,
167/,6

17%

7%
61f..
5lf..
4%
41,;i

12'12

9%
7%
6 1/ ..
5 th
15

15'12

59A.

6 5/"

8 1a

5 1At.

SH/16

73/16

45f.

5%,
4 3/4
47116

6 7/16
57/8
5 7/J()
5'4

3 ",
3 3/1(.

4%
3%
3 't/H.
3 1/2

14

lQlIa
8 7/16
7 3/,.

3

3 5/1.

Ph

PS/16

2 /,
'
21/"
2%
2 1h
2 '/16

33ft,

1~16

2'11,
2V2
2%
2V"
23f.6
2%
2
l 's/u;
FIs

2 5/14.

29/H.
2J,;i

21/4
2'4

F.4
P/4

l'1ft6

1%
1'/14.

I'll

4'/..
4
3%
5

2%

11ljH.

23f'6
2%
2

PI.

115ft,

l

l1A6

1%

7

15
11 3/lf.
8"/'6
7'/4
6'/..

33/~

2
F4
P.4
l"/u•
Ph,

0,460
0.490
0.500
0.510

14%.
14'h
14'h

3%
3 3/16
3
2%
2"/'6

1%
1511,
1'/..

0,430
0.440
0,450
0.460
0,470

0.625

2%
2112
2%
2%
2%
2 1/14.

0.180
0.190
0.200
0.210
0.220

0.360
0.390
0.400
0.410
0,420

0.562

4 11.
4%6
4%
3 1311.
3'/,6

2

0.330
·0.340
0.350
0.360
0.370

0.500

33/ ..
3 711.
33116
3
2 H I1,

13
/"

2
113/16
111/H.
19/H;
Ph

0.280
0.290
0.300
0.310
0.320

0.469

11

0.130
0.140
0.150
0.160
0.170

0.230
0.240
0.250
0.260
0.270

0.438

1%
113/1(,
P/..
111/11>

3'/H.

2'V"
2 13/1(.
2'1ft6

16 116
167/H.
15 7/1ft
11%

171,;i .
1711s
17%
16'S/I(,

91f2

12%

1

10%
9'4
81f'6

4 3/"
4 711,
4 1/16
4

3 1lA6
3%
3'12
3%
3 3/16

71f4

6%

6%
5.'1J!6
5S/16
5
4·%
.,4'h
4 5/H.

4'/8
3t~%6

313f16

2'''6
2V2
2%
2 s/16
21/4

3%
3
271s

2 11/,.

3%
3 1/4
3Yu.

21/,.
2%
2 1A,
2
11s/16

2%

3V,.

2112

27/u,

3
27.11

2%
25111>

213A6
2%

Pia

2'/4

l H /".
1%

2 3/1(,
2%
2 1/1(,
2
11SJIi,

2%
2'11"
2%
27/16
2%

213j1(,

FIs

3%
3%

25/1(.
2 1/ ..
23/16
2 11a
211a
2 1/16.
2
115/u.

Table 3-7

ASME B31G-1991

TABLE 3·7

VALUES OF L fOR PIPE SIZES

D~pth,

. d, in.
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
0.110
0.120

0.312

0.375

0.438

0.500

nil/if.

15
15
15
12'4

16'/4
16'/4
16'/4

17%

12'/..
81/"
5'lf16
4%

13 11/1(,
10'4
7 3/H.

3lf4

5 11/H.

8"/16

3'1.

4 13/16
4 J/,ft
3lf4

6 1S/16
5 74

2'5/'6

2%
2%

7

3%

4%

6'/8
51f2
5
4%

3'4

4 3/11.

2'4

3%

2 11/16

39/'6
35/16
3 11a

2%

0.180

19/16

0.190

P/u.

0.200
0.210
0.220

1%

2 3/11>
2'/11,
2
Pia
113/16

0.380
0.390
0.400
0.410
0.420
0.430
0.440
0.450
0.460
0.470
0.480
0.490
0.500
0.510
0.520
0.530
0.540
0.550
0.560

1%
P/4

14
10l/a.
8lJ,ft

5 3/1f>

1JI/,&

0.330
0.340
0.350
0.360
0.370

0.625

0.688

17]4

19%

2<Y4

173~

19%

15"/1&

19%

20%
20% .

11%

19%

12'1..

0.130
0.140
0.150
0.160
0.170

0.280
0.290
0.300
0.310
0.320

NPS 30 AND < NPS36

Wall Thickness, t, in .
0.250

2lf16
21f,&

0.230
0.240
0.250
0.260
0.270

~

2 1h

1"/16

1%

2 1S/H.

4'/4
4
3%
3'%10
3JIa

17%

9'/".
8'/,&

18'5/1f•
14 7/,&

20%
20%
20%

7'/11>

1F4

15 1311,

6%

lOl/a

13 1/16
11'/.

51)/".
5~/16

7%

9

6 1l/H.
6%

aV'6

5%

79;"
7'/,&
6%

55f,,,

6'/4

2'12

31/".

2%

3

3lf"

2%

2'/4

2%

3'/16

3

2 /'6

21/4

1

2 'IIf.

2%

2

1 'S/If.

2'/1/.
2 7/,&

1 13/16
1%
1 11/,&

2'/4
21f,.

214

2'/8
2
1'5/16
Pia
1 1311&

9 15/'6

4'SJ'6
4%
4%
4'/8
3'511.

2]/4

9
8'/16

5lSlI&

1
/".

34
3'/4
3'4
3

41]/".

5 15/u.
5%

4%
4 7/,&

5'4

4'1.

4'511&

2%
2 1l/'1>
2 11116
2%
2'12

41f'6

4 3/4
4%.
4%
4'/.
4'4

2 7Ab
2%
2'1.
2 Jill.

37/16

214

5

3'%.
3'lflf.

3 "/u.
39/lf.

5%

)5/u.
3 1/.

4
3%
3 3/.

3 11a

3%

31fu.

39/16

2'11&

2 1S/II,

3 711&

2

2%

3%

2 IJ/I(.

31f.

2 3/.

33/16

2;'1".

3'1a

Sf".

, 1

2"/16

3

2'h
271,&

2 1Sh6
2 718

25f'6

2'lJ'6
2lf.

2~/H'

2 11/16

21/4

2%

2%

23/".

2"/16

2'12
7

2 1"

2%
2Sf'6
25f16

-

ASME B31G-1991

'-'Table 3-8

TABLE 3·8

VALUES Of L fOR PIPE SIZES?: NPS 36 AND < NPS 42
Wall Thickness,

Depth,

d, in.

0.250

0.281

0.030
0.040
0.050
0.060

13'/11.
0:-;11.
9

141/~

14'/~

13'4
1

8h

O~070

6 VII.

0.180
0.190
0.200
0.210
0.220

0.375

15
15
11'/a
7 71,.

16 7/1h

in.

16~/1I.

18'/11>

13'/~

4'18
4'111

7%

6"/11.

3V~

4 I'1>

3 1/11
2''1,1>

4'/~

5%
4"1,1>

3''1",

4~/,,,

0.420

22'1lh

11'>11

22'1".
22'11/.
22'"'1,,,

9''1,,,

17"1'1>

8'h
TI"

14'1".
12'111.

7V'b

10'~/lh

6%

2'11/.

2v"

4 'Is

21f1>.

2'1/u.

ria

4~1II

2 111"
1''1u.
llYIf.
1%

27/11>

3VII

61f'I>

]711"

5''1,,,
50'110

2'/11>

1%

11'ollh

3'/"
3'1a
2''1",

2'1,1>
2 1/1&

22'1."

6"111>

l l '/l!.

2 1111,.,
2"/11,

0.380
0.390
0.400
0.410

20'4
20'4
18''111.
14'/4

1 15/u.

2 'VII-.
21h

2'%"

0.330
0.340
0.350
0.360
0.370

0.688

6'/u.
5 11/11>
5 1/4

2'/.
2 V...

0.240
0.250
0.260
0.270

0.300
0.310
0.320

18:-;".
13"/11>
10%
8:-n.

5111".

37,111>

Q

0.562

18:;'h

11%
9 1/1"

0.230

0.280
0.290

0.469

18 7/11>

5'/~

rill.

r.

0.406

167/11>

6'/~

0.080
0.090
0.100
0.110
0.120
0.130
0.140
0.150
0.160
0.170

0.312

9'1f1"

5'/lh
4~/1I

3'h
3'/11

4 11/1"

)'/4

4~/lb

21h

3'4

21/A

3

4'1"
4'/11
3''Iu•

2~/"

3'1/1/.

5'111.

2'/4

3"/,,,

5

2 11ft ..

3'h

4"1".

2~1t.

Y/lh

411/1h

2'h

lVI "

4'h

2

2

3

2"/11•.

3%
3' '11h

2'1/",

3'%b

2'I!

3'h
3 11a

21'h

0.430
0.440
0.450
0.460

0.470

3

0.480
0.490
0.500

rIll

2'V'h

2' '1lh

0.510
0.520

2'1.

0.530
0.540
0.550
0.560

2V"

2"/",

21/:

Copyright© 1991 by the American Society ofMechunical Engineers.
No reproduction may be made of this material ·without vlritten consent of ASME.

Table 3-9

ASME B31G-1991

TABLE 3-9
Depth,
d, in.

0.030
0.040
0.050
0.060
0.070

NPS 42 AND < NPS 48

0.406

0.438

0.469

0.500

0.562

18%
18'h

191/16

191J16

2P/4

18%

193116

21 1/ ..

12%

9

0.625

0.688

0.750

2P/4

22 15/16

22 15/H>

24'/,6
24'/1f,

25%
25'1a

22'5/16

24'/16

25'18

22 7h6

9 11z

211/..
207/,6
15%
12 9/16

241f'6
241f1l.

25%
25'/8

8%

103/ ..

25 th
20'k
16 13/1f.
149/16
127/8
11%
10'V16
9%

17

85;,6

0.120

4"/16

0.130
0.140
0.150
0.160
0.170

45/1(,

16 /1/.
121J16

6%

9%

5'S/'6

8 3/,6
7'/!f.
6 5/11.

9 3/4

5 11/16
51116
4 l3/u.

6%

Sif4

Sif4

7'/4

19%
t 4 13116
11'h

20%
189/16
131/4

9911"
8 S/16

1111&

7%
6"ft6
6'4
5%
5'1.

17'/,6

7'12

9%

fill/If.
6 5/H.

8 1/2

5%

73f16

99/'6
8lf..

18 1/ ..
15 7/11.
135/11.
11 13116
10%

14
12'/,&
10%

3'1/16
37/16

47/16

)'/4

43116

5 ,s116
57/16
S1fIl;
4'1flf.

3I Sf,.,

47/16

4'5/16

6 11/16

8'/16

91'/16

3 116
3%

43f'6

4"/16

7lfz

9

3 a/1I.

4 7/t(,
4 3/16
4

6V4
5%

]lIn.

8%

5'%6

6%
6 5/lf.

7%

4

0.180
0.190
0.200

11

3YII
3 3/16

0.210

0.220

0.280
0.290
0.300
0.310
0.320

~

Wall Thickness, t, in.
0.344

0.080
0.090
0.100
0.110

0.230
0.240
0.250
0.260
0.270

VALUES OF L FOR PIPE SIZES

2)18

3lJ16

2'/4
2%
2'/'6
11)/'6

2 1S/H,
2 11J1f,
211/16
2 9/11;

3
/4

3
39/11;

3 13/1(.
3%
3'/2
3%

7%

5 5/u>

43/16

771&

SlJlb
4 13/16

6

4%

57/'6
5'/..

6%

31/16

3%
3'1J16
39/H.

5

5'lf)f,

2 n/16

3%

7
/16

3
2%

3
3Sfl6

4%

2"/1f,

3 '5/1(,

4%

33/16

313h6

4%

2)/4

3'/16

211fU.

215/16

3 11/111
3 9/1&

45/'6
4lJ'6

29/16
2'/i
2%

4

4 /16
4'/.
7

2%
2)/..

0.330
0.340
0.350
0.360
0.370

211/16

2%
2'12

5 11/U.

4

7
6 11/16

61f16

13/1&

4'/16

411/16

315/U.
3 13/16

4'116
47116

311/16

4 5/16

4'5/U,

3%

4)/16

4%

215f1!,

0.390
0.400
0.410

2%
2 111l&
2lJ4

3J/~

0.420

2%

31'11&

5'/16

3%

3
2'5/16
213jl6

0.460
0.470

5%
5%

4'/".
3'VH.

0.380

0.430
0.440
0.450

93/'6
8%

2 3/.

4 '/16
4
3%

3 D /If.
31/4
3%

0.480
0.490
0.500
0.510
0.520

3'1/11•

3'h
3%
35/16

22

ASME B31G-1991

TABLE 3-9

Table 3-9.
~

VALUES Of L fOR PIPE SIZES

NPS 42 AND < NPS 48

Wall Thickness, t. in.
0.812

0.875

0.938

1-.000

1.062

Depth,

1.125

1.188

1.250

d, in.
0.030
0.040
0.050
0.060
0.070
0.080

2M/16
2M'"
26311,
26)11.

271h6
27 3/11.
27 1h.
273116

Z7

31%

2&116
26l /16

3
/16

28%

29 111.

27 111r.

28%

291f16

29 lS/,.
29 15/1(,

2P/.

273/16

28%

29 1/16

29 15/1(.

18lfu;

23 5/"

28%

29Vu,

153/.

199ft6

24 1111,

291f16

29'Sf'6
29'5116

26 1/ ..

29 SJu,
27%
23'h
20'/16

15
/"

1

14
12 1V'6
11%

17

20

15%

)8'1.

13"h6

161f..

leW.

129116

1.43/4

2211.
197;'11;
17%

10

11%

13'/16

15 3/ ..

187/16

12 h,
lP/4
l1 1h6
107/16

14%
13 7/16
12'/u.

16

9%

7

9 h6
8 71a

8 7/ "
8

7

10 4
101(..

9 11f16

9

21 13/16

26%

313/~

19"/u.

23

275ft6

17 13/16

24%

19 T3A,
185/16

13'/1f,
12 11116
121f1.

15V.

11lh

12 13/1(,

11

12'1"

8

6 14
5'~%6

6'4
6 11/1(,

5%

6 7/t6

7 11/11.
77/16
7%,

5 h6

6'/4

5%

(?'/lfi

3 '5/ "
31AJ
33/.

3 Pia
30 7/16

11 Ylr.
10ll/16
lOS/1I:.

71As

4

24 13/16

11'5f,6

11 13/16

15%r.

915/H.

7
6l / ..

75/16
71fu.
6 74
6"/,6
6'h~

13 1h

6 t.
6 '116
5 15/16
513/u.

6

9'/16

107A6

11 iIi.

9%

10'lu•.

11

1OVa
105/16
10
9"1i6
93,18

1

61f2

7h
7%6
7 ';'

6%

814
8

8%

8 7/a,
81f..

7

5 11/1.

6 1lA6

77/H,

5'1/16

6 liAr.
69/,6

7%
71Ja
6 15116
61)11"

57/".
55/16
51J..

M~

6%

23

9 11a

l /lf.

8
7 u/u.
7%

6"/16

15Vl"
14'/.
13 9ft6

1013/1(.

l11f.

7 11/1.
/1t;

17
15 1Sjlr.

913/16

11"1,.

1031t6

73/16
13

2P/..

121S/H.
12%
1F4

109/"

7%
7

1

14%

8'116
7 13h6
7%

6%

32711"
32 7h6
32 7116
32 7h6

lm~

6>116

5%
51Ju.
4 1511&
41)/"
4lf..

31%
31%

31%

10%

91f..
8 15/1(.

4 3/4

3 Ollh 6
30 U /16
291f'6

16%

7%

4\)/16

32 7h..
327/16

141/ ..

6'/"

5
51f1f.
4 15/14,

31%

11 3/16

9 11ft6

1
/16

32 7/16

17%

7"/16

61J..
6 1A6
5 '5/U.

31%

16%

6'%6

6

3013/1,
30 nh6
30 1311,

15%

8 5/H.
8

6%

3Hl,

14 5/u.

7%
7'116,

9
/"

31%

30 1311f>

13%
12%

]lV16

41fa

3
/ ..

32 7/H,
32 '/16

3013/H.

20 11/u>
1813/16

9 3A,
83/4

9

0.090
0.100
0.110
0.120

8"/16

8 1/1.
7%
7 U /16
'P/16

7%

0.130
0.140

0.150
0.160
0.170

0.180
0.190
0.200
0.210
0.220
0.230
0.240
0.250
0.260
0.270
0.280
0.290
0.300
0.310
0.320
0.330
0.340
0.350
0.360
0.370
0.380
0.390
0.400
0.410
0.420

0.430
0.440
0.450
0.460
0.470
0.480.
0.490
0.500
0:510
0.520
(table continues)

. Table 3-9

ASME B31G-1991

TABLE 3..9
Depth,
d, in.

VALUES .OF L FOR PIPE SIZES

~

NPS42 AND < NPS 48 (CONTD)

Wall Thickness, ~ in.
0.344

0.406

0.438

0.469

0.500· 0.562

0.625

... .-.

0.530
0.540
0.550
0.560
0.570

0.688

0.750

2 1311.
2 31c
2 11A.

3'1.
31h,
31,\
3 'h, :
3

0.580
.0.590
0.600
0.610
0.620

2'Sft.

r,\
21%.

0.630
0.640
0.650
0.660
0.670
0.680
0.690
0.700
0.710
0.720

.....

"

0.730
0.740
0.750
0.760
0.770
0.780
0.790
0.800
0.810
0.820
0.830
0.840
0.850
0.860
0.870
0.880
0.890
0.900
0.910

0.920
0.930
0.940
0.950
0.960
0.970

0.980
0.990
1.000
1.010

24

Table 3-9

ASME B31G-1991

TABLE 3..9

VALUES OF L FOR PIPE SiZES ~ NPS 42 AND < NPS 48 (CONT6D)

0.812

0.875

0.938

3"1l.

,WI.

3%

3 'h

4 h,
'
4
3'0/",

4 sle
4'h,
4 711,
4%

37;'.

3'4

4s11~

3l },
35f1.
3'/.31A.

33/.

31th6
354
]9h6

4'1..
4'4
4 'h,
4

)lfe

)112

)ISA.

39h.

7h ..

3'116
3

Wall Thickness, t, in.
1.062
1:000

1.125

1.188

1.250

Depth,
d, in.

6%
6
5'511,
5 ul1"

6 11/16
6'%.
6 7/16
6 5h6
6lJu.

7%
7 14
615/u•
6 1l/u.
6"116

0.530
0.540
0.550
0.560
0.570

6'/16
6
5%
5 3/.
5"/u.

6'A6
6 7116
6 3},
6'/..
6%

0.580
0.590
0.600
0.610
0.620

5'11 ..
5%
5%
55A,
5%

6'/11;
5 ' 5ft,
51)/1£.

0.630
0.640
0.650
0.660
0.670

5%
51Ju.
5

59/,.

5'}'

5%

5
4 '5/16
4 1l/1€.
4%

5'h
5 7h6
5 5/".
5 3/1(.

4 1111,

5';'
5
4 1S/16

59ft.
51h

47;'

55h6

4 3/.

5 3/16

5110
5%,
4 '5/,.

4 1/16
4

41t/u.
4 5A.
4'/16
4'A6
4%

4'A •.
4'h
4 7A.
41},

5 11;'"

5 14

3

3 1e

31til

3 11A,

35h"
)'1"
33h6

3 3/ ..
3 11116

3%'
3%
311'1(.

39116
3 11l
3'h6
3%
3sfu,

3 'SA6

4 s/u.

374
) 13/14.
33/.
3"ft.

4%
4 311,
4 14
4%,

4 3/ ..
4"116
4 911,
4%
4 7116

3%

3%
3'11,
3%

4

4 11a

4)/..

3 1$/u.
3%

)1/16

3 1l/H.

4 5/16
4'1..
4 3/H;
4'4

4"/tr.
4%
4 9/1(.

4'1"

4'/'6
4%
4 5,1,6
4'1.
4 31i6

7

3%

3 JA,

3%

4 '/..
4 3A,

4'4

7

3 ft.

331..

3%
35A6
3'1.

3"/16
3 11A,
3%
3'%,
3%

J1/u.
3%

4%

4 13/u.

4
3'5116
3 15A..
3%

3 1lA6
33/ ..
3 u/u.
3%
3%
3'/'6
3 1h
3'h6

.....

'"'

4 15/16
4%

4%

5 3/ ..
5"/16

5lfl
5 7/H.
5·SfH.
5 If..

53/1(.
5 '4
5
4 '5/16
44
'
4 11ft,

4%
4"/16
4%
4'A6

4%

41h

41,1,

4 1116
4%
4 5/16

4'116
4
3 15ft,
37~

4%
4 '/.
4)/11.

0.680
0.690
0.700
0.710
0.720
0.730
0.740
0.750
0.760
0.770
0.780
0.790
0.800
0.810
0.820
0.830
0.840
0.850
0.860
0.870

3))116

4'~

3 1/4
3'V16

41J'6
4

0.880
0.890
0.900
0.910
0.920

35~

3 15A,
3 IS/If.
3%
3 13A6
33/ ..

0.930
0.940
0.950
0.960
0.970

3V4
3'V"

0.980
0.990

3%

1.000

3 13/"

3%

3'/t.

1.010

2S

Table 3-10

ASME B31G-1991

TABLE 3·10

VALUES OF L FOR PIPE SIZES ;:e NPS 48 AND < NPS 52

Wall Thickness, t, in.

Depth,
d, in.

0.030
0.040
0.050
0.060.
0.070
0.080
0.090
0.100
0.110
0.120
0.130
0.140
0.150
0.160
0.170

0.344

183/,6
18 3A6
l

18 A6.

ll t1/H.

13

73,10

109/u.

M'i6
5%

5'h6
4%

4'1.
3'5116

3 11/16
3 7/)f,

3'/..
3 1/ "

0.220

2%

0.280
0.290
0.300
0.310
0.320

1
/ ..

8'5h6

0.180
0.190
0.200
0.210

0.230
0.240
0.250
0.260
0.270

0.406

2,sll&

2 3/ ..

3
/ ..

8
PAr.
6 3/ ..

0.438

0.469

0.562

0.625

0.688

0.750

2WAr.
209/H.

21'1..

21'5/1r.

2n~

21 1511(.

20"/".

21 V..

21 'S/I(.

17 ' 1j16

2]1/..

12%
l()3h

15 13/16
12 5/16
lOY..
8%

21 'Sf'6
191)/16

23'/4

25 1/4
25 1,4
25lf..
25 3/.
25 3/ ..

267/a

167/16
137ft,

249/16
24'/16
249ft6
24
18'/..

815ft6
8

11%
10'1.

15
12%

20.
16'12

26%

7':>/16

9%

11%

141/4

63/ ..
6'1..

8 5h6
7 11/IIJ

10'/4

12%
11%

4%

55/,6

5%

4%
4 1.4
4
3 13A6

5
4 11/11;

5'12
51/16

7%
6 1'/H.
6 5/,6

8 13/1f.
7 3/ ..
6 ' 5f16
6 s/H.
5 13/16
5%
5 1/1t.

0.500

11

14 A6
11'>;1&

HP/'6

4'12

4 15/16

4'/..

4 11j1{.

4%

23'1..
21%

1
/.-

4%
3'5/"

3'11f.

3 1l/1&
3"/'6
3%

4%
4'/4

3l le

3SJ'6
3 3/16

3

45/,6

3 5/'6
V/,6
3 1ftr.
2 15/'6

3
27h
2)/4

2 11/16
2 9/,6

2%
2lf..

0.330
0.340
0.350
0.360
0.370

2"/'6
2 9/,6
2%

27/11,

3 1/16
3
2 71e
21l/1I.
2'1J16

21%
18
. 15 9h6

13 13116

9%

11%
10'/,&
913/16
9'/..

Gl;11

7'h

8lth6

6%

7%

5 1 3jlf.

6'.ljJ6

81J4
7'/8

59/16

61h

5%

6J;4

7'/2
7J/16

41fu.

5 3/1f>
5
4 13/16

6%
6%
6%

3 '5/16

4%

3 ' YJ6

4V2

6lJ'6
515/16

3 11ft6
3<)/11>
3 7/16
3%
]1/..

4%
4 1/4

21l/u.

4"/16

4
3 1sA6

49ft"
4'h

3 1/4

3'/1&

354
3'/11.

0.470

2'%6

371,6

3lJl"
3'4

5
4 13j'6

4%

0.430
0.440
0.450
0.460

3 13/16
33f4

YI8

0.480
0.490
0.500
0.510
0.520
CopyrightO 1991 by the American Society of Mechanical Engineers.
No reproduction may he made of this material v,1thout written consent of ASME.

2674

127/u.

8%
7 15/,6

33/16
31f1f,
3
2 15/,6

0.380
0.390
0.400
0.410
0.420

267/a

10%
8'511&

5 1s/16
5 11/1&
5%
5%
4 '5/16
4 3,4
4 9/16

3"/'6
3 1h
3 3/a

9%

26 7/a
267/a

3'3j1f>

3"/H.
3 5/11

3'116
@

~

26

ASME B31G-1991

Table 3-10

VALUES OF L FOR PIPE SIZES ~ NPS 48 AND < NPS 52

TABLE 3·10
0.812

0.875

0.938

Wall Thickness, tin.
1.000
1.062

1.125

1.188

1.250

Depth,
d, in.
0.030
0.040

0.050
0.060
0.070
0.080
2St'/a
29 A6

28
28
28

'
29'/16
291J;6

301f16
301f16
30'/16

28

291J16

30lJl~

28

291/16
29 1/16

30'A6
30'116

24'5/u ,
20 1S/16

30 1/1f.

16 13/16
14 15/16

18 /lf,

13 11&

163/16

12%
11 '12
lOll.

1411/,6

28

0.090
0.100
0.110
0.120

31 1/H.
311111.

32
32

32 15/'6

32

32'%6

32
32

26'116

31'/16
31lJu.
31'116
31 'lt6
31'/1(,

22%
19'h
17%

281f'6
23 3/.
20V.

7

13 /16

is}/.

9
/16

18

12 7/16

14'12

1M'a

9%

11%
101s/\6

9
89/16
83Ju.

lOS/if.
9 11/16
9 5/u;

13 1116
129ft &
11'3j'6
11%
10'/16

15'h
14%
13 7116

10VI6

11%

23 1/.
19 '/11.

9

lOlA 6

3

8 15/1(.
8'A6
8 3/16
771a

12%
11 15/1f.

32

34 11/11.
34 11A6
34 11/11.
34 11/1(.
3411/1&

0.130

32 1S/If.
32 15/U.
32 15/16

3313/'6
33 11/u,
33 11/\6
33 13/16
33 13/16

32 15/lf,

3313/16

32 15/16

13

33 A6

19"/,6

23 5/16

33 13A6
32 9/16
27 1S/16

0.180
0.190
0.200

22

31'A6
26%

34 1111&
34 11/16
34 1 '/16
3411/16
33 'S/H.

1715116
16 th
15 5A6
145116.

20'S;,&

24911.

293J16

19'116

251)/16

16 5/16

22%
201ft
189/u,

13'/2

15 1/.

171/.

23 1/.
211116
199116

0.230
0.240
0.250
0.260
0.270

12 31.
1214

14%
13"%6

163/16

183/16

151;"

147/1(.
t 3 11/\f.

17 1/H.
16 1ft&

32
32
29 1h
25'Ia

17%

9%

10 1l/'6

91f4
8 '1a

10%
9 1$/1(,

1 P/16

12 15ft6

l11J'6

7%

8'/16

9'/16

10%

125J1I;
11 13/ 16

6%

7%

8%

65/11.

71~

7 15ft6

6%

6%
611/16
6 1h

7 11f16

515/u,

5 3/4

50

6 /16
6'4

6
5 1l/16
S"/u.

71f2
71/4
7'/u.
6718
61Vu.
6 1h

6

5/16

713/"

7'/16
7%
71/16
7

0.210
0.220

0.280
0.290
0.300
0.310
0.320

13 1/16

14V2

12%
12

Hll/'6

10%

11'/1(.

10%

1111a

1211/u;
12 3/16
1P/-4.

0.330
0.340
0.350
0.360
0.370

11%
11
tO ll/I(,
105J16
10'/16

0.380
0.390
0.400
0.410
0.420

93/4
9%
9%

0.430
0.440
0.450
0.460
0.470

10lfl6
9 U/16
9 1h
9 3/1&
8%

11 S/16

9 3/.

10%

8%
8lf.
81fa

9%
93fu.
8 1Sft&

10%
10 1/,,,
9 31..

7%

8 11A"

9 1/}

7"/16

8'/16

9 1/4

10%

4'5/,6
4 1lft.
411/'6

61)A ..

71h

6%
6%

75/u.

4%
4'/2

6318
6 3/16

6 1l/ "

4 15/16
4 B/'6

6 1116

6'1ju.

75/16

715j,.

SIS/H.

6%

71f1ll

7 3/.

4)/4

513116
5 11/H.

6%

7

7%

4%

6'/.

4'/16

5'/16

6%

6'lju.
6 11116

71/1&
75/16

7%

7

27

15 1/4

0.140
0.150
0.160
0.170

13%

91f16
8 1%6

0.480
0.490
0.500
0.510
0.520
(table continues)

Table 3-10

ASME B31G-1991

TABLE 3-10
Depth,
d, in.

VALUES OF L FOR PIPE SIZES

~

NPS 48 AND < NPS 52 (CONT D)
6

Wall Thickness, t, in.
0.344

0.406

0.438

0.469

0.530
0.540
0.550
0.560
0.570

0.500

0.562

0.625

0.688

0.750

3

0.580
0.590
0.600
0.610
0.620

3%

3'/16

3

0.630
0.640
0.650
0.660
0.670
0.680
0.690
0.700
0.710
0.720
0.730
0.740
0.750
0.760
0.770
0.780
0.790
0.800
0.810
0.820
0.830
0.840
0.850

28

Table 3·10

ASME B31G-1991

TABLE 3·10

VALUES OF L FOR PIPE SIZES ~ NPS 48 AND < NPS 52 (CONT'DI

0.875

0.938

4 7/16
4%
4 1/ ..

4 1SJ'6
4%
4-%

3lJ..
3%

4 1/'6

11

39/u.
3'h
3'/16
3%
3 5/1«.

4IJu;
3 15f,.
3 7,4
3131.6
3 3/ ..

0.812
31511(,

Via
313116

4%

3'1..

3'lJ16

V/16

3%

39/u.
3%
37/H.

3%
3 Sf16"
3'1.

4 116
4%

4th
4'/16
4%
4'1..
4)/,6
4%
4lJu.
4

Wall Thickness, t, in.
1.062
1.000

1.125

1.188

1.250

6'116

7%
7
6%
6%
6%
61h

73/ ..
7'/16

5 1h
5%
5 1/4
53/lf.
5'116

6
5%
5 0 /1f.
5 11/11>
S'y"

5
4%
4 13/16

5'h
5%

6
5%

5'/.,

4 3/4

5)/..

5%
511116

6)/,6

7'116
6 15/16
61)/.6
6 111. ..

4%

5%

5%6

61Ju.

6'1"

5%
5%
5 5116
51f..

15

5 /\1.
5'h

6 7/l6

5)/4

6%

5 1J/16
5%

6%

4
4lJ2

9/u.

5
4 '5')6
47/11

6 7/16
6 S/16

63ft 6
61J16

6%

6 1/ ..

7 7/,6

75/'6
73f16

6%

Depth,
d, in.
0.530
0.540
0.550
0.560
0.570
0.580
0.590
0.600
0.610
0.620
0.630
0.640
0.650
0.660
0.670

3 1sA.

4 7/1(.
4 5/H.

3%

4 '/.

4lJ4
4 11A..

4 /,6
4%
4lJ16
4
3 15oA6

4%
4'%6
4'12
4'1.6
4 5/ ..

0.680
0.690
0.700
0.710
0.720

3718
3 Ul16
33/4

3%

4%
4 3/H.
4%
4 1/,6
4

0.730
0.740
0.750
0.760
0.770

391.6

315/'6

3'/11.
3'12

315A6

0.780
0.790
0.800
0.810
0.820

13/16

3
33/.
3"A6

3%
39/16
3lit
3%6
3%

3

311;16

3%
3 u/u
33/4
311/lf.
3%

29

5%

6'111.

0.830
0.840
0.850

Table 3-11

ASME B31G-1991

TABLE 3.. 11
Depth,
d, in.
0.040
0.050
0.060
0.070
0.080

VALUES OF L FOR PIPE SIZES ~ NPS 52 AND < NPS 56

0.406

0.438

0.469

20'116

2P4

20'/11.

21%
21%
187/1(.

22'4
22%

Wall Thickness, t, in.
0.500
0.562

22%

22'1fu.
221)/16
22 H/'6

22'4

22 13/11;

241/H.
241/1l.
24 3/11.

0.090

13 7

16%

20%

24 3116

0.100

1011/"

0.110

93116

1213/,6
10'1j,6

15 5/16
12%

0.120

81ft,

0.130

7%

9%
8 3/\6

10911,
9 5/16

22%
17%
14
11 15/,6

109/,6

20'116
14511,

116

9/16

0.140

6

T/l6

8%

0.150

0.160
0.170

61f16
5%
5%

7%
7

0~180

4 1S/'6

61.'11(,
6 5/H.
5%
5'12

4%

53/1(,

4 71.6

4%

4 31.6
4
3 13/'6

4 11116

0.190

0.200
0.210

4'4
3'S/H.

0.625

0.688

25 9/1(.
25 9/16
25
19

26 lJ/u,

28

26 B/'6
2613/16
26 13/16
20 nA,

28

17 lt6
1413116

22'116

0.750

28

15%

13%
11 B/n,

J

28
28
28

6'h

9%
8 ' 1f'6
8

6%

7 7ft ..

9

11 1l/1f.
lOU/H.

12 15/16

5 3/ ..
57/1,6

6'S/H,

B%

10

1Fla

69/'6
63fu,

7%

gSf16

11

7%
7
6%

8%

10'/4

10%
93/ ..

13%

18%
163Ju;
14%

4 7/1(,

5'4
4%

4%

4 11/16

5%
5%

0.240

4112

5%

6%

89/1(.

0.250
0.260
0.270
0.280

4 5/16
4'/3

51';'

83/'6

3 15/16.
3 U/16

4 1/4
4 9/1()

6'/16
SHIH)
59/16

3%

0.220

3~/H'

0.230

3%

0.290
0.300
0.310
0.320
0.330

0.340

4'%,

3 11A6

4%

5~,

2%

3 91.6

23/ ..
2 lt/H,
29/,6

VA6

4'/..
4 11a
3 15/16
3 13/1(.

5
4'3ju)
4 11/,6
4112

3V16
21)/16

0.350

2 ' Vlf.

0.360
0.370
0.380

2%

2'12

31f16

3
2%
2 U/'6
23/4

0.390
0.400
0.410
0.420
0.430

9%

7 1J;H.

"9lJ'6

7 u /u.

7'12
73J16

534

3

3S/16

8'/..

4%

6
5 13/16
5%

5 7/16
5'/.
5'116

513/1£.

4%

4
4 13/H.

5%
5'h

4

411/1&

. 55ft"

3%

4%

4%

15/16

53/16

31l/16
3 1 1jj&

4%

3%
3'h
37/16

4 3/ ..
4 11/110
4'IJ6

511.6

4
3%
3 13/16

0.440
0.450
0.460
0.470
0.480

3"/,6
3%
3%

3 15A&
3718

0.490
0.500
0.510
0.520
0.530

3u/lf>
3 11/16
3%

Copyright © 1991 by the American Society of Mechanical Engineers.
consent of ASME.

~U1'

W

ASME B31G·1991

TABLE 3-11

0.812

0.875

Tabla 3·11

VALUES OF L FOR PIPE SIZES ~ NPS 52 AND < NPS 56
0.938

Wall Thickness, t, in.
1.000
1.062

1.125

1.188

1.250

Depth,
d, in.
0.040
0.050
0.060
0.070
0.080

29%
291,1.
29'4
29 '/.

29 1/.
29'4
24 1/1&
20 l /u.
17'h

lS·/u.

30%
301/.
30'/.
30Y.
30%
30%
30%
25'Sj'6
21 3/.
18,s/1(.

315/11,
31 5/,6
31 5/"
31 >/1(.

3P/H.

315/;"
31'/;"
27%
23 s/)(.

16
15'1..
14
12's/u.
12%

2OS/H.

9%
9%

11%

8'5/u;

141f1f.
12 ' Sj'6
11'Sj16
11 l/H.
10'12

8 9/u.
8)/11.

7%
79/16,
7'/4

7
/8

18';'
161A6

33 5/16
33 5/,6

34'/4
341J4

35lf16
35%6

33$A6

34'14

33 s/'6
335/16

34%

35 3/"
35 3/16
35 3/16

29 3/1()
3
/ ..

24
21%

33$A&

11

30 /1f.
26%

34 '/"

36%

36 ;'
'
36'1&

36'1&
36'1$

34'/..
32 5/".
27%
24',4
2P/..

35 1/,6

19 11/'6

23

26 7; ' ~

20 J5/'6

24 111&

16 1s/'6

19Sf'6

15'4
14'5/,6

17'5;16

22'/u.
20%

16 13/16

18'S/'6

15';'
15

171/ ..

353f16
33%
29'/,6
25%

36 1/a
36 1; '

221Sf'6

14

16'/&

20'12
18 11/,6

101/ ..

13 1/,6
125/,1.

14 1 Sju.
14

1<Yh6

11%

13lfu.

911/16
g5/'6

11
10 'h

12'/16

173/,6
15 '5/1/.
14'Sju,
14ljJ(.

11 13A6

13'/..

8%

10'/1(.

'I.

12%
12

14'/8

11112
11'/16

12'3j".
12'/..
11%

14%

13

163f4
15 13/,1>
151fte.
14%

11 5/,6
1074
10%

12'12

13)/.

12
11'/16
1 PA6
10'3j16

13 J/16

7'1ju,

9%

9'14
8 7/8
8"/11.

11

10%
10s/lf.
9'%&
9 9/11>

10%

7lf'I>

9 1/4
8 H /II>

10'1.
9'1e

77/1b
6'5/,6

8%

9 9/16

6 J/.

BlJa

641J6

8'/s

9'/.
8 15/11.

6%
61f4

7'IB

7'/8

6'5j1l;

7"/11>

71/2
7'/4

7'/8

5
5%
5'/..

6'/16

5 A.

6%
69/,1>

5 1/8

511"

6 7/'1>

5
474

5%
5'12
5%
51f4
5'/.

4'/11>

32Sfu.
32>;",
32 5/16
32 5/1(.

1~A6

613/t6

4 13/'6
4 11/16

33 S/)f.
33 s/H.

15'/11.

7

9
/11>

32 5/lf)
32 5/1(.
32Sflf.

195/,6

8"/16
8'/4
7'5/16

5"/16

0.090
0.100
0.110
0.120
0.130

15

18

1
/4

131/11>

10l /lf,
9%

8'1j'6
87/16
8 1/4
8

13%

36'1&

35 5/,(,
30%

12 ' Vu,
12'1..
11'3jtr.

101h
101/1f,
9 71B

11 7/u.

9%
9%

0.140
0.150
0 ..160
0.170
0.180
0.190
0.200
0.210
0.220
0.230
0.240
0.259
0.260
0.270
0.280
0.290
0.300
0.310
0.320
0.330
0.340
0.350
0.360
0.370
0.380

11 'Is

0.390
0.400

10V.

0.410

1071"
103/",

0.420
0.430

6'5f'6

7%

8 5A6

9 lIB

0.440

6 J/ ..

77/'b

8%

0.450

6%

7'/4

67/,~

7%

6 5/,1>

6 " /,1.

7 1'/16
7 1/ ..
79/'6

8 11a
8 1 '1.1>
8'/11.

5'/'6
4 15/16

6 '/u.

4 tJ/16
43/ ..
4%

SISAl>
5 11/1(,
5 11/11>

6Y'b

31

0.460

81f.

0.470
0.480

8 '/11,
7'5/11•
711..

0.490
0.500
0.510

r/'6

0.520

77/,1.,

0.530
(table continues)

Table 3-11

ASME B31G-1991

TABLE 3..11
Depth,
d, in.

VALUES OF L FOR PIPE SIZES ~ NPS 52 AND < NPS 56 (CONT'D)

Wall Thickness, t, in.
0.406

0.438

0.469

0.500

0.540
0.550
0.560
0.570
0.580

0.590
0.600
0.610
0.620
0.630
0.640
0.650
0.660
0.670
0.680
0.690
0.700
0.710
0.720
0.730
0.7:40
0.750
0.760
0.770
0.780
0.790
0.800
0.810
0.820
0.830
0.840
0.850
0.860
0.870
0.880
0.890
0.900
0.910
0.920
0.930

0.940
0.950
0.960
0.970
0.980
0.990
1.000
1.010

32

0.562

0.625

0.688

0.750

ASME B31G·1991

TABLE 3-11

Table 3-11

VALUES Of L fOR PIPE SIZES

~

NPS 52 AND < NPS 56 (CONT'D)

Depth,

Wall Thickness, t, in.
0.812

0.875

0.938

4'/,6

4 9/1(.
4 7;',

51flf.
,5
4 /"
474

3 SA,
'

1.000

1.062

1.125

1.188

1.250

d, in.

5911,

6%

6 11/1(,

5%
5 14
50/"
5 1/16

6

6'A,

75J",
7%
7
6 74
6 3/.

7%
7%
7%
77/,6

0.540
0.550
0.560
0.570
0.580

5%

3%

4%

1l

3 A,

4 S/u.

4\)/16

31/.c

4 1;',

4 1111,

3 11ft,

41J.

4%

3'ft,

4 ft,
'

4'h

3'1,

4
37k
3 13ft.

4 7h,

37/16
3%
35/11.

33/ ..

4 116

4"ftlt

3 11ft6

4%

4%

51/16

3%

4'h6

4%

4 '5116

3 h6

4

47/11.

3%

31S/'6

4%

4%
413h6

37/,.

3%
31311,
33/.

4 5ft 6

4%

3 11/16

t

3%

4%
4 5ft,
3

S

13/u.

5 ' 1j16

6 7/"
6 S/'6
61f04

5 14
5
4 ,5/1,
413h6

S9/"

61"..

5%
5%

4 1/.

5%

6
S%
S 13h,
5" /16

SSh,

6%
6'1,6

7 5/ "
7)/u.

65fI(,

6'3fl'

6 3/,6

6 HI16

0.590
0.600
0.610
0.620
0.630

6',\

6%
6%·
6%
6 s/H.
61J16

0.640
0.650
0.660
0.670
0.680

6'/16

7'ft 6
6 '5/'6

5%
5%
57/u.
5%
Slfo4

6
S'S/If.
SUh6

4%

5 3116

5%

6%

6

5%

S1§/16

41f.

4%

S'k
5
4'%;

5"/11.

4 3/u,

4 11/'6
4'1A6

3%

4%,

4 7h,

4%

5lJe
S5/16

5%

0.690
0.700
0.710
0.720
0.730

3'/"
3%

4

4%

4 13116

5'/.

3 'SI1,

4 5lt6
4Y.

4 3/.

5 3lt6
5%

S ltft6
S%
5112
5 7/16
5%

0.740
0.750
0.760
0.770
0.780

4%

S5116

4 '3ft6

5 1/.
S1Ju
5 1ft6
5

0.790
0.800
0.810
0.820
0.830

5 ''\

3%
3 13/,6

4lflt.

]3/.

4%

311/16
3%

4 1/16

4 11116
4%
4 9ft 6

53/ ..

S
4 '5/16

51)/1(.

313/'6

4'12
4 711.
4%
4 5/16
41J04

313h6

4 3/u.

4'/lf.

4 '5/,6

4%
41f16
4
3,5/,6

4%
47/16

4%

4%

4%

4
3 1V'6
3%

3%
313/u•

4 3,4
4 11/1(,

4%

4'lf16

451t6

4 ' 1ju.

4lf.
4 3/1(.,

4%
4 9/16
4112

4'18

4 1h

41/1i

4'/li

4
3 1Sft6

4%

4 3/16

0.840
0.850
0.860
0.870
0.880
0.890
0.900
0.910
0.920
0.930

4 11s

0.940
0.950
0.960
0.970
0.980

4%

0.990

4 s/"
4 1/4

4 3/16

4'116

1.000
1.010

33

Table 3-12

ASME B31G-1991

TABLE 3-12
Depth,
d, in.

VALUES OF L FOR PIPE SIZES ~ NPS 56 AND < NPS 60
Wall Thickness, t, in.
0.500
0.562

0.406

0.438

0.469

21%
21%

22 3/11,
221ft6

21%

22Jft,

14 11/11;

1911a

22 15A6
22 15/16
22 '5A6
22 '5116

23 11/u,
23 11ft 6
23 11/16
23 11/16

8 311(,

11'/..
9 9/1(.

17'1t6
135J16
11'A,

7 1/ ..

8%

99ft6

217/16
15%
12%
11
9 11ft,

0.625

0.688

0.750

29'116
29'ft6

0.040
O.O~O

0.060
0.070
0.080

13

15
/16

25'4
25%
25%

26%

25%

26%

23%

26'1z
25 15/16
1911/16

2713ft,
27 13116
27 H I1,
2713/16

161/u.

21%

1015116

13%

9 74
9

12 1/ ..

17%
15%
13%
12'/..
ltV..

23%
19'i'16

8 11/16
8'As

10%
9 11/16

12S/u.

9 1lt6
89ft 6

0.090
0.100
O.pO
0.120
0.130

117/H>

6'/16

7'12

8'12

0.140
0.150
0.160
0.170
0.180

6

6tl/16
6 1/4

7"/1£.

8"/16

7'ft6

7%

5U/t!>
57/16
5%

6'12

7 5/16

4 13J16
4 9/16

6 1/1(,
511/16

6%

6 5/16

8 5/16
7'1A6

0.190
0.200
0.210
0.220

4Y,6

410/16

5%

5 1Sft6

7'14

0.230

31f2

0.240
0.250

3%

9' h

5'/16

5l ft6

4 1ft6

3'4
311/16

5%

55/,6 -

67/16

4 '/a
3 15/,6
313/'6

4%
4%

51f16 -

6%

71V16
71/ ..

4%

5 1%6

6%

8'1a

9 7/,6

4%
41ft 6
41f..

5'/u.
5 5ft6
5 lAs

6 9ft 6

7111..&

8 U/If.

5
/16

6
6 1/16

7%

81h

7VI6

814

414
3 '5116

4'>;!6

SU/,6

6 3/ ..

73/ ..

77ft6

31flf.

0.270
0.280

215ft6

3'12
3 5/16
33ft 6

0.330
0.340
0.350
0.360
0.370
0.380

14%

137/16

5'/16
411/u.

0.260

0.320

161lt"

49f'6
4%

3%

0.290
0.300
0.310

11'/H.
10%
9 5/'6

29'/,6
29 1/H.
29'/16

61)ft,

3'1.

2%

17%
14'h
127/1,

26%

4 1/16
4

3%
3''116

3'/,6

3 1lA£>
3 11ft6

3'/,6
3
2%

39/16

2%
2 11116

37/u.
35/16
2%

2 /u,
2 11/1&
2%
13

1/ ..

5 ft 6

6%

49/u.
4%
4 1/ ..

5%
53116

5

6'1..
6
513/,6

4%

4%
4 ' 1ft6

57A6

4

4

9

3 3116
3'~

4 ' 1f16

0.390
0.400

3 11,

0.410

V/..

0.420
0.430

3%
39/1(.

15

5%
511116
5 12
'
5%

4 '5ft6
41)/,6

41/ ..
4
3 15ft.

2%

31)/16

3%

311/16
3 1/\6
3

0.490
0.500
0.510
0.520
0.530
Copyright © 1991 by the American Society of Mechanical Engineers.
No reproduction may be made of this material without written consent of ASME.

6 1/,6

5'1..
5 '/,6

3 13/'6

0.440
0.450
0.460
0.470
0.480

915/16

5%
511..
5%
5
4 13ft6

3
2 15/16
2 13/16

lHl
10%

4%

4
3 '5/16
374
3)/..

~

~

34

ASME B31G-1991

TABLE 3·12

Table 3-12

VALUES Of L FOR PIPE SIZES

~

NPS 56 AND < NPS 60

Wall Thickness, t, in.
0.812

0.875

0.938

1.000

1.062

1.125

1.188

1.250

Depth,
d, in.

0.040
0.050
0.060
0.070
0.080
30lfll;
303116
301116
3()l/16

301/"

31%
31%

31%
31%

30 3/lf.
25'4
21
l8Yl6
163/16

31%
31%

14%
13%
121/a

17'h
1513/,6
141/2
131/16
12'/16

11"/u,
1 Q1."

36'/u.

37 11z

0.090
0.100
0.110
0.120
0.130

369/u.
369/16
36'11,

371J2
37'12
37'12
371f2
37'h

0.140
0.150
0.160
0.170
0.180

31-%

26'51i,
22'/16

19%

13
/16

11
1 Pia

10'/,6
10'116
9%

91J..
8 71a

32'h
32'h
32 'h
32'h

349/u.
34'/16
3491i6

32 112
32'h
32'h
28 ' 1flli
2411i6

33%
33%

21'/16

25 11A6

1813/16

17IJu.

221116
2011'16

15%

183/16

14'12

1M'~

33'12
33'12
305f16

359/16
35 9/16
359/16
35%;,
35 9/u.

36'/'6
36"/'6

3 Fie
27'/a

35 91i6

36'/H.

37'12

33 9/1&

23 3/ ..

28%

36%6
35 311,

21 sl1ft

25 l /u.

30%

37'h
37'h
3M-iI

19%

22 9/16

269/16

3P/16

0.190
0.200
0.210
0.220
0.230

15%
14112
1311/16
12 15/1(,
12'1..

107A,

11 11/,6
11 311,
10" /16
1m''16
9 15/"

10%
10%
9 71a
99/H.
9 5116

8"116

7Y'6

8'1..

7'/,1.

7'511 ,

6 Ul16
6%

711/16

8%

9'%6

]7/,6

9%

6%6

7%

6'/"
6'/16

7

8 5/u;
8 1/H.
713/Ui
7%

1S
/16

34'/16
349ft,
349/1£.
349/16
349/lf.

13'/,6
121/ ..
12'/16
11 7116
10%

8l1a
7 13/,6
79116

10
99/'6
9'/..
8%

815/"

8"/1(,
8 7/11.

36'/16

1711/16

9

7

20 116
18 '5/16

23 /a

27%

0.240

21 3/.

17%

201116

25'/16
227/8

16%

18%

21'1.

0.250
0.260
0.270

151J2

177/16

19%

0,280

13'116
12%
11 15/16
11 7h6

141t/16
13 1%6
13 5/16
12lJ.

167/"
15"/16

187/H,

0.290

17%

0.300

16 7/If,

0.310

15%

11

12 3/16

14 13/1 ..
14%
13'12

0.320
0.330

145/16
13"/16
13 l/'6
1211/u,
12 S/16

0.340
0.350
0.360

11%

0.390
0.400
0.410
0.420
0.430

16'116
15'12
14'/16
13 3/ ..

3
/16

1 PI.

12 15/16

115ft..

12~

101S/"
10"/16
10'1.

12
1Pia
111/4

14'5/16

5
5)/.-

7%
73/16

8

7 15/16

9%

5·%
5 7/1(.

7
6 13/16
6 11ju.

73f.

9%

7'/16

911.

9'S/H.

7%

8 7/,

9 11/'6

5%

6%

7 3h6

77As

101/ ..

5

6%

7
671.
6 11/11.

7 ll/l 6
]911&
734
7 l/I&

10

55/16
1

V16

59/16
7
/16

6)/16

5
55/16

6lJH.
5 15/16

5'/..

5 13/16

51fa

sH/16

5
4'5/u•
4°/16

59/16
57/16
5%

6'116

9'5ft,

6 7/16
6 5116
6%6
6'116

35

10 1a
10"/,6
101J..

11112
113f16

t0 71.
109/H.

9 3/4
99/11.
9'>/16

7 11/16

9%

]9ft6

7%

8 lla
8'%6
89/1&

7%

8%

73,4

515/'6

1

0.370

0.380

0.440
0.450
0.460
0.470
0.480
0.490
0.500
0.510
0.520
0.530
(table continues)

ASME B31G-1991

Table 3-12

VALUES Of L FOR PIPE SIZES

TABLE 3-12
Depth,
d, in.

0.406

0.438

0.469

;;:!:

NPS 56 AND < NPS 60 reONT'D)

Wall Thickness, t, in.
0.500
0.562

0.540
0.550
0.560
0.570
0.580

0.625

0.688

0.750

3lJl6

3"jl()

3%

3%

Vlu.
37/u.
3%

3 s/,,;
3 1/4

0.590
0.600
0.610
0.620
0.630
0.640
0.650
0.660
0.670
0.680
0.690
0.700
0.710
0.720
0.730

... ..
~

." ....

0.740
0.750
0.760
0.770
0.780

,.

0.790
0.800
0.810
0.820
0.830

.....

"

0.840
0.850
0.860
0.870
0.880
0.890
0.900
0.910
0.920
0.930
0.940
0.950
0.960
0.970
0.980

..........

0.990
1.000
1.010

36

.......

ASME B31G-1991

TABLE 3-12

Table 3-12
VALUES OF L fOR PIPE SIZES ;,NPS 5& AND < NPS 60 (CONT'D)
Wall Thickness, tin.
1.000
1.062

0.812

0.875

0.938

4lf16
4%
4
3 15/16
3%

4 1111,
4%

5'1..

5 Ul16

Mia

5%

4 15/16
474

5 A,
59116
5%
5)'"

611..
Mia
6
515116

311ft 6
lV..
3%
3'A6
31f2

4Sf16
4 3/16
4 11a
4 1116

411/16

55/16

4 '116
4%
4 9A6

5%
5

4

47/16

4'% ..

5 13116
5 11116
5 s/s
5'h
57h6

7

3 A6

4'%,
47/16
4l la

3 u/u,
3 11/16
3Y.
3'111,
3%
9
/16

3
3%

51A.

1

11

5 3/16

l

4 /s

4 1,..

5

4%

4 11"
4%
43/11;
4'111)
4
31S/If.
3%

31.1A"
33/..
3 ltl16
3%

d, in.

6 1S"6
6 13/1'
6"116
6 911,
6 7/16
63,..

7'''6
711H.
15/11.
7%
7

8 3116
8Y"

0.540
0.550
0.560
0.570
0.580

771a

7%
7%
7711,
7s/u,

6%

6 tl/H.

6
5 1%6

6'A.
67116

5 5A.
5%

5 13/16

51~

5'4
59116
57116

6 5116
6%
6%
6'A6
5'5116

69/16
6 7/16

0.640
0.650
0.660
0.670
0.680

5 1/s
55116
5'1..
5%
5'11,

5%
51/ ..
5 11116
5%
51J2

65/1(,
6 1/..
6 '1a
6%6
6

0.690
0.700
0.710
0.720
0.730

5
4'5/1,
4%
4314
4 1ft6
'
4%
4'%.
4 1h
47/16
4%

57A6

5'1.

5%

SH/'6

ss/!.

5%

53116
5%

59/,.

0.740
0.750
0.760
0.770
0.780

5
4,sA6

4%

13

5%6

4 3116

4 A.
4 3/ ..
4''116
4%

4%

4'/u,

41/16

4 1h

4
31511.
3%

4 7A,

3'lfl6

4'1..
4)116
4'1,
4 '116
4

J%

1.250

67fa
6 1/ ..

4 7/t6

41f..

1.188

6%

4"A.
4%
4 9A,

4V16

Depth,
·1.12S

4%

4 5h.

31Sf16

53/ ..

5'A6
5
415116
47A1
41.1/'6

40/1.
4'/.t
4 3/u.
4%
4'4

4 3/ ..
4 11A6
4%

4'1".
4

4 7/1f;

4'1"
4'h
4%
4%,.

4'1.
4 3,11.

4%
4%

7lJu.
7'/16
7
6%
63/ ..
6%

5%

51h

57/16
5%
St;..
53/16
5 '4

5'11'
5
4 15A6
4%
413;'6
4 1/.
4'1IH.
4%

49A6
4'h
4 71,6
4 1/"
4)/s

4 sA,
4 1/ ..

4}/'6

37

0.590
0.600
0.610
0.620
0.630

0.790
0.800
0.810
0.820
0.830
0.840
0.850
0.860
0.870
0.880
0.890
0.900
0.910
0.920
0.930
0.940
0.950
0.960
0.970
0.980
0.990
1.000
1.010


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