ASTM D2122-22

Standard Test Method for Determining Dimensions of Thermoplastic Pipe and Fittings

SIGNIFICANCE AND USE
5.1 This test method provides for determining the physical dimensions of thermoplastic pipe and fittings. This test method is suitable for determination of dimensional compliance with product specifications.
SCOPE
1.1 This test method covers the determination of diameter, wall thickness, and length dimensions of thermoplastic pipe. Included are procedures for measurement of the inside diameter of pipe intended to be joined by internal fittings, measurement of the average outside diameter for roundable pipe where out-of-roundness is not of primary concern, out-of-roundness measurement and measurement of the average outside diameter of non-roundable pipe, and for determining length and straightness.  
1.2 This test method also includes procedures for dimensioning molded thermoplastic pipe fittings.  
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Jun-2022
• ICS: 23.040.20 - Plastics pipes
• ICS: 23.040.45 - Plastics fittings
• Technical Committee: F17 - Plastic Piping Systems
• Drafting Committee: F17.40 - Test Methods

Relations

• Refers: ASTM F412-20 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Apr-2020
• Refers: ASTM F412-19 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Jan-2019
• Refers: ASTM F412-17a - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Aug-2017
• Refers: ASTM D790-17 - Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials
• Effective Date: 01-Jul-2017
• Refers: ASTM F412-17 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Feb-2017
• Refers: ASTM F412-16a - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 15-Nov-2016
• Refers: ASTM F412-16 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Aug-2016
• Refers: ASTM D790-15e1 - Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials
• Effective Date: 01-Dec-2015
• Refers: ASTM D790-15 - Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials
• Effective Date: 01-Dec-2015
• Refers: ASTM F412-15 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Jun-2015
• Refers: ASTM F412-13 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 15-Feb-2013
• Refers: ASTM F412-12 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Apr-2012
• Refers: ASTM D638-10 - Standard Test Method for Tensile Properties of Plastics
• Effective Date: 15-May-2010
• Refers: ASTM F412-09 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-May-2009
• Refers: ASTM D618-08 - Standard Practice for Conditioning Plastics for Testing
• Effective Date: 01-Nov-2008

Overview

ASTM D2122-22 is the internationally recognized standard test method for determining the physical dimensions of thermoplastic pipe and fittings. Developed by ASTM International, this test method provides comprehensive procedures for measuring key dimensional parameters such as diameter, wall thickness, length, and straightness. It ensures that thermoplastic piping products meet defined product specifications and comply with quality requirements, supporting their safe and consistent use in a range of applications.

Key Topics

• Dimensional Measurement: Procedures to accurately measure inside diameter, outside diameter, wall thickness, and length of thermoplastic pipes and fittings.
• Type of Pipes Addressed:
  • Roundable pipe: Pipes that can round out in a socket.
  • Non-roundable pipe: Pipes that retain shape due to higher modulus of elasticity or geometry.
• Measurement Tools: Utilization of calibrated micrometers, vernier calipers, plug gauges, circumferential wrap tapes, and out-of-roundness gauges.
• Measurement Reporting: Requirements to document minimum, maximum, and average measurements, out-of-roundness, and ovality where applicable.
• Precision and Bias: Emphasis on instrument accuracy, with no inherent bias in the methods when followed as specified.
• Alternate Methods: Users may validate alternate measurement approaches (such as ultrasonic or electronic) if they meet quality criteria.

Applications

ASTM D2122-22 is widely used in industries that manufacture, test, or install thermoplastic piping systems. The standard is critical at several stages:

• Quality Assurance: Used by manufacturers for routine verification of pipe and fitting dimensions before products are shipped.
• Compliance Verification: Assists regulatory bodies and auditors in checking that thermoplastic piping products conform to specified tolerances.
• Product Development and Certification: Essential for laboratories and certification bodies when qualifying new thermoplastic pipe and fitting designs.
• On-site Inspection: Supports installers and contractors in confirming dimensional compliance before installation, reducing risk of leaks or joint failures.

Typical sectors relying on these standards include construction, water and wastewater management, chemical processing, and gas distribution.

Related Standards

ASTM D2122-22 is frequently used alongside several other key standards:

• ASTM D618 (Practice for Conditioning Plastics for Testing): Specifies how to prepare and condition plastic specimens.
• ASTM D638 (Test Method for Tensile Properties of Plastics): Used to determine tensile properties, relevant for classifying pipe materials.
• ASTM D790 (Test Methods for Flexural Properties of Plastics): Used for determining flexural modulus, which helps define pipe categories.
• ASTM F412 (Terminology Relating to Plastic Piping Systems): Provides definitions crucial to interpreting D2122-22.
• ASTM F1498 (Specification for Taper Pipe Threads for Thermoplastic Pipe and Fittings): Governs thread dimensions for certain joints.
• ANSI B2.1 (Pipe Threads): Addresses threading requirements, complementing ASTM F1498 for standardization of connections.

Practical Value

Adherence to ASTM D2122-22:

• Ensures pipes and fittings interconnect reliably and safely.
• Minimizes risk of dimensional noncompliance, enhancing product performance and lifespan.
• Supports regulatory and industry compliance for thermoplastic pipes and fittings.
• Facilitates international trade of thermoplastic piping materials by providing a clear benchmark for dimensional conformity.

By following this standard, manufacturers, engineers, and inspectors can confidently specify, verify, and utilize thermoplastic piping systems across diverse applications. For the most accurate and current requirements, users should always reference the latest published version of ASTM D2122.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D2122 − 22
Standard Test Method for
Determining Dimensions of Thermoplastic Pipe and
Fittings
This standard is issued under the fixed designation D2122; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* D638 Test Method for Tensile Properties of Plastics
D790 Test Methods for Flexural Properties of Unreinforced
1.1 This test method covers the determination of diameter,
and Reinforced Plastics and Electrical Insulating Materi-
wall thickness, and length dimensions of thermoplastic pipe.
als
Included are procedures for measurement of the inside diam-
F412 Terminology Relating to Plastic Piping Systems
eter of pipe intended to be joined by internal fittings, measure-
F1498 Specification for Taper Pipe Threads 60° for Thermo-
ment of the average outside diameter for roundable pipe where
plastic Pipe and Fittings
out-of-roundness is not of primary concern, out-of-roundness
measurementandmeasurementoftheaverageoutsidediameter 2.2 ANSI Standard:
ofnon-roundablepipe,andfordetermininglengthandstraight- B 2.1 Pipe Threads (Except Dryseal)
ness.
3. Terminology
1.2 This test method also includes procedures for dimen-
sioning molded thermoplastic pipe fittings.
3.1 Definitions:
3.1.1 General—Definitions are in accordance with Termi-
1.3 The values stated in inch-pound units are to be regarded
nology F412, unless otherwise specified.
as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only
3.1.2 deviation from straightness—the maximum deviation
and are not considered standard.
fromastraightlineexhibitedbyapipespecimendividedbythe
length of the specimen.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.1.3 nonroundable pipe—pipe made from a material hav-
responsibility of the user of this standard to establish appro-
ing a tensile or flexural modulus of elasticity of 150 000 psi
priate safety, health, and environmental practices and deter-
(103 MPa) or greater, as determined by Test Method D638 or
mine the applicability of regulatory limitations prior to use.
D790, and in addition, having an outside diameter/wall thick-
1.5 This international standard was developed in accor-
ness ratio of less than 20.
dance with internationally recognized principles on standard-
3.1.3.1 Discussion—The above definitions apply to thermo-
ization established in the Decision on Principles for the
plastic pipe and are based on the ability or inability of a pipe
Development of International Standards, Guides and Recom-
to round out when forced into a tapered socket.
mendations issued by the World Trade Organization Technical
3.1.4 roundable pipe—(1)pipemadefrommaterialhavinga
Barriers to Trade (TBT) Committee.
tensile or flexural modulus of elasticity less than 150 000 psi
2. Referenced Documents
(103 MPa) as determined by Test Method D638 or D790; and
2 (2) pipe made from a material having a tensile or flexural
2.1 ASTM Standards:
modulus of elasticity of 150 000 psi (103 MPa) or greater, as
D618 Practice for Conditioning Plastics for Testing
determined by Test Method D638 or D790, and in addition,
having an outside diameter/wall thickness ratio of 20 or
This test method is under the jurisdiction of ASTM Committee F17 on Plastic
greater.
Piping Systems and is the direct responsibility of Subcommittee F17.40 on Test
Methods.
3.1.5 socket bottom—the point at which the pipe stop
Current edition approved July 1, 2022. Published September 2022. Originally
radius intersects wall.
approved in 1962. Last previous edition approved in 2016 as D2122 – 16. DOI:
10.1520/D2122-22
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2122 − 22
when using ball anvil micrometers, which may compress the specimen
4. Summary of Test Method
andgivefalselylowreadings.Careshouldbetakentoavoidmisalignment
4.1 Alternate Methods—Alternate methods and procedures
of the anvil with the longitudinal axis of the specimen when using
for obtaining dimensions (such as apparatus and procedures
cylindrical anvil micrometers, which may bridge specimen surface cur-
vature or indentations and give falsely high readings.
using laser, electronic, nuclear, ultrasonic, or other means) are
not prohibited.
7.2 Procedure—Make a series of measurements at closely
4.1.1 The user of an alternate method shall validate the
spaced intervals to ensure that the minimum and maximum
alternate method. The alternate method is validated when both
wall thicknesses have been determined. Make a minimum of
the product is measured according to the Apparatus and
eight measurements.
Procedure sections presented in this test method, and when
7.3 Calculation:
found to be in compliance with product specifications.
7.3.1 Calculate the average wall thickness by taking the
NOTE 1—Validation of the alternate method is a necessary step in
average of all values measured.
ensuring compliance with product specifications. Validation generally
7.3.2 Calculate the wall thickness range, E, as a percent, as
involves statistical analysis of data generated using the alternate method.
follows:
At a minimum, the analysis should include calculating 99 % confidence
limits and verifying that these limits are within the product specification
A 2 B
E 5 100 (1)
tolerances. For guidance on this type of analysis, the user should consult
A
the Manual on Presentation of Data and Control Chart Analysis.
where:
4.1.2 Compliance with product specifications shall be based
A = maximum wall thickness at any cross section, and
on the measuring apparatus and procedures in this test method.
B = minimum wall thickness at any cross section.
While alternate methods are not prohibited, the measuring
apparatus and procedure in this test method shall be the referee
7.4 Report—Report the following information:
method.
7.4.1 Observed minimum and maximum wall thicknesses,
7.4.2 Calculated average wall thickness, and
5. Significance and Use
7.4.3 Calculated wall thickness range in percent.
5.1 This test method provides for determining the physical
dimensions of thermoplastic pipe and fittings.This test method
8. Inside Diameter Measurement of Roundable Pipe
is suitable for determination of dimensional compliance with
8.1 Apparatus—Depending on the requirements, the follow-
product specifications.
ing apparatus shall be used:
8.1.1 Tapered Plug Gauge, for checking conformance to an
6. General
average inside diameter tolerance, having uniform taper of
6.1 Specimen Preparation—Pipe specimens shall be cleanly
1:100 and accurate to within 61 % of its taper and to within
cut and burrs removed. Some materials, such as polyolefin
60.001 in. (60.02 mm) of its diameter. For each given pipe
plastics, may undergo dimensional change near cut ends due to
size and tolerance specification, a mandrel shall be scribed at
internal stresses. When this condition is noted, care shall be
the diameters representing the minimum and maximum allow-
taken to make measurements at a location which is not so
able inside pipe diameters. To aid rounding, a 45° by ⁄8 in.
affected.
(3 mm) face bevel shall be provided on the entrance end of the
6.2 Conditioning—Condition the test specimens at 73 °F 6 gauge.
4 °F (23 °C 6 2 °C) and 50 % 6 10 % relative humidity for
NOTE 3—Where internal stresses cause change in dimension at the cut
not less than 40 h prior to test in accordance with ProcedureA
end of pipe, tapered plug or sleeve gauge measurements may give
ofPracticeD618,forthosetestswhereconditioningisrequired
misleading results.
unless otherwise specified by the relevant ASTM material
8.1.2 Metal Rule (if it is desired to determine the actual
specification.
average inside diameter) with at least 0.01 in. (0.2 mm) gradu-
6.3 Test Conditions—Conduct tests in the Standard Labora- ations.
toryAtmosphere of 73 °F 6 4 °F (23 °C 6 2 °C) and 50 % 6
8.2 Procedure:
10 % relative humidity, unless otherwise specified in the test
8.2.1 Cuttheendofthepipesquareandremoveburrs.Insert
methods, in this test method or specified by the relevantASTM
the plug gauge into the pipe, causing it to round out but not to
material specification.
expand. Observe whether the end of the pipe falls between the
scribed diameters.
7. Wall Thickness—Pipe and Fittings
8.2.2 In cases of disagreement between the purchaser and
7.1 Apparatus—A cylindrical or ball anvil tubing microm-
the seller, the proper insertion distance as indicated in 8.1.1
eter accurate to within 60.001 in. (60.02 mm) shall be used
shall be defined as that point where an internal light source is
for wall thickness measurements.
just occluded.
8.2.3 If the actual average inside diameter is required,
NOTE 2—Care should be taken to avoid excessive closure pressure
measure the distance from the maximum scribed diameter to
the end of the pipe.
Committee E11 on Quality and Statistics, MNL7A Manual on Presentation of
8.3 Calculations—Calculate the average inside diameter as
Data and Control Chart Analysis, Chapter 2, ASTM International, West
Conshohocken, PA, 1990 , p. 38. follows:
D2122 − 22
d 5 d 2 kl (2) 9.2.2 Sleeve Gauges—Cut the end of the pipe square and
m
remove burrs. Insert the pipe into the sleeve gauge and observe
where:
the position of the end with respect to the ends of the tapered
d = average inside diameter, in. (or mm),
sleeve gauge or the position of the end with respect to the
d = maximum scribed diameter, in. (or mm),
m
minimum and maximum scribed marks of the sleeve window
k = taper of plug gauge, in. (or mm) of diameter per in. (or
gauge.
mm) of length, and
9.2.3 Circumferential Wrap Tape—To determine the actual
l = distance from maximum scribed diameter to end of
valueoftheaverageoutsidediameter,placethecircumferential
pipe, in. (or mm).
wrap tape around the pipe, making sure that it is at right angles
8.4 Report—Report the following information:
to the pipe axis and is flat against the pipe surface. Observe the
8.4.1 When determining conformance to tolerances, report
diameter reading, estimating to the nearest 0.005 in. (0.1 mm),
whether the average inside diameter is less than the minimum,
or 0.001 in. (0.02 mm) as required.
greater than the maximum, or within the allowable limits as
9.2.4 Out-of-RoundnessGauge—Todetermineconformance
indicated by the position of the scribed diameters with respect
to pipe out-of-roundness with the gauge, the pipe shall be
to the end of the pipe.
inserted through the gauge without forcing rounding of the
8.4.2 If the actual average inside diameter is required, the pipe.
result of the calculation in 8.3, as well as the values used in the
9.3 Report—Report the following information:
calculation,shallbereported.Theaverageinsidediametermay
9.3.1 When determining conformance to tolerances with the
also be calculated as described in 10.5.
tapered sleeve gauge, report whether the average outside
diameter is less than the minimum, greater than the maximum,
9. Outside Diameter and Out-of-Roundne
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D2122 − 16 D2122 − 22
Standard Test Method for
Determining Dimensions of Thermoplastic Pipe and
Fittings
This standard is issued under the fixed designation D2122; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 This test method covers the determination of diameter, wall thickness, and length dimensions of thermoplastic pipe. Included
are procedures for measurement of the inside diameter of pipe intended to be joined by internal fittings, measurement of the
average outside diameter for roundable pipe where out-of-roundness is not of primary concern, out-of-roundness measurement and
measurement of the average outside diameter of non-roundable pipe, and for determining length and straightness.
1.2 This test method also includes procedures for dimensioning molded thermoplastic pipe fittings.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D618 Practice for Conditioning Plastics for Testing
D638 Test Method for Tensile Properties of Plastics
D790 Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials
F412 Terminology Relating to Plastic Piping Systems
F1498 Specification for Taper Pipe Threads 60° for Thermoplastic Pipe and Fittings
2.2 ANSI Standard:
B 2.1 Pipe Threads (Except Dryseal)
This test method is under the jurisdiction of ASTM Committee F17 on Plastic Piping Systems and is the direct responsibility of Subcommittee F17.40 on Test Methods.
Current edition approved Nov. 1, 2016July 1, 2022. Published November 2016September 2022. Originally approved in 1962. Last previous edition approved in 20152016
as D2122 – 15.D2122 – 16. DOI: 10.1520/D2122-1610.1520/D2122-22
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2122 − 22
3. Terminology
3.1 Definitions:
3.1.1 General—Definitions are in accordance with Terminology F412, unless otherwise specified.
3.1.2 deviation from straightness—the maximum deviation from a straight line exhibited by a pipe specimen divided by the length
of the specimen.
3.1.3 nonroundable pipe—pipe made from a material having a tensile or flexural modulus of elasticity of 150 000150 000 psi
(103 MPa)(103 MPa) or greater, as determined by Test Method D638 or D790, and in addition, having an outside diameter/wall
thickness ratio of less than 20.
3.1.3.1 Discussion—
The above definitions apply to thermoplastic pipe and are based on the ability or inability of a pipe to round out when forced into
a tapered socket.
3.1.4 roundable pipe—(1) pipe made from material having a tensile or flexural modulus of elasticity less than 150 000150 000
psi (103 MPa)(103 MPa) as determined by Test Method D638 or D790; and (2) pipe made from a material having a tensile or
flexural modulus of elasticity of 150 000150 000 psi (103 MPa)(103 MPa) or greater, as determined by Test Method D638 or
D790, and in addition, having an outside diameter/wall thickness ratio of 20 or greater.
3.1.5 socket bottom—the point at which the pipe stop radius intersects wall.
4. Summary of Test Method
4.1 Alternate Methods—Alternate methods and procedures for obtaining dimensions (such as apparatus and procedures using
laser, electronic, nuclear, ultrasonic, or other means) are not prohibited.
4.1.1 The user of an alternate method shall validate the alternate method. The alternate method is validated when both the product
is measured according to the Apparatus and Procedure sections presented in this test method, and when found to be in compliance
with product specifications.
NOTE 1—Validation of the alternate method is a necessary step in ensuring compliance with product specifications. Validation generally involves statistical
analysis of data generated using the alternate method. At a minimum, the analysis should include calculating 99 % confidence limits and verifying that
these limits are within the product specification tolerances. For guidance on this type of analysis, the user should consult the Manual on Presentation of
Data and Control Chart Analysis.
4.1.2 Compliance with product specifications shall be based on the measuring apparatus and procedures in this test method. While
alternate methods are not prohibited, the measuring apparatus and procedure in this test method shall be the referee method.
5. Significance and Use
5.1 This test method provides for determining the physical dimensions of thermoplastic pipe and fittings. This test method is
suitable for determination of dimensional compliance with product specifications.
6. General
6.1 Specimen Preparation—Pipe specimens shall be cleanly cut and burrs removed. Some materials, such as polyolefin plastics,
may undergo dimensional change near cut ends due to internal stresses. When this condition is noted, care shall be taken to make
measurements at a location which is not so affected.
6.2 Conditioning—Condition the test specimens at 73.4 6 3.6°F (23 6 2°C) and 5073 °F 6 4 °F (23 °C 6 2 °C) and 50 % 6 10 %
relative humidity for not less than 40 h prior to test in accordance with Procedure A of Practice D618, for those tests where
conditioning is required unless otherwise specified by the relevant ASTM material specification.
Committee E11 on Quality and Statistics, MNL7A Manual on Presentation of Data and Control Chart Analysis, Chapter 2, ASTM International, West Conshohocken,
PA, 1990 , p. 38.
D2122 − 22
6.3 Test Conditions—Conduct tests in the Standard Laboratory Atmosphere of 73.473 °F 6 3.6°F (234 °F (23 °C 6 2°C)2 °C) and
5050 % 6 10 % relative humidity, unless otherwise specified in the test methods, in this test method or specified by the relevant
ASTM material specification.
7. Wall Thickness—Pipe and Fittings
7.1 Apparatus—A cylindrical or ball anvil tubing micrometer accurate to within 60.001 in. (60.02 mm) shall be used for wall
thickness measurements.
NOTE 2—Care should be taken to avoid excessive closure pressure when using ball anvil micrometers, which may compress the specimen and give falsely
low readings. Care should be taken to avoid misalignment of the anvil with the longitudinal axis of the specimen when using cylindrical anvil
micrometers, which may bridge specimen surface curvature or indentations and give falsely high readings.
7.2 Procedure—Make a series of measurements at closely spaced intervals to ensure that the minimum and maximum wall
thicknesses have been determined. Make a minimum of eight measurements.
7.3 Calculation:
7.3.1 Calculate the average wall thickness by taking the average of all values measured.
7.3.2 Calculate the wall thickness range, E, as a percent, as follows:
A 2 B
E 5 100 (1)
A
where:
A = maximum wall thickness at any cross section, and
B = minimum wall thickness at any cross section.
7.4 Report—Report the following information:
7.4.1 Observed minimum and maximum wall thicknesses,
7.4.2 Calculated average wall thickness, and
7.4.3 Calculated wall thickness range in percent.
8. Inside Diameter Measurement of Roundable Pipe
8.1 Apparatus—Depending on the requirements, the following apparatus shall be used:
8.1.1 Tapered Plug Gauge, for checking conformance to an average inside diameter tolerance, having uniform taper of 1:100 and
accurate to within 61 % of its taper and to within 60.001 in. (60.02 mm) of its diameter. For each given pipe size and tolerance
specification, a mandrel shall be scribed at the diameters representing the minimum and maximum allowable inside pipe diameters.
To aid rounding, a 45° by ⁄8-in. (3-mm) in. (3 mm) face bevel shall be provided on the entrance end of the gauge.
NOTE 3—Where internal stresses cause change in dimension at the cut end of pipe, tapered plug or sleeve gauge measurements may give misleading
results.
8.1.2 Metal Rule (if it is desired to determine the actual average inside diameter) with at least 0.01-in. (0.2-mm)0.01 in. (0.2 mm)
graduations.
8.2 Procedure:
8.2.1 Cut the end of the pipe square and remove burrs. Insert the plug gauge into the pipe, causing it to round out but not to expand.
Observe whether the end of the pipe falls between the scribed diameters.
D2122 − 22
8.2.2 In cases of disagreement between the purchaser and the seller, the proper insertion distance as indicated in 8.1.1 shall be
defined as that point where an internal light source is just occluded.
8.2.3 If the actual average inside diameter is required, measure the distance from the maximum scribed diameter to the end of the
pipe.
8.3 Calculations—Calculate the average inside diameter as follows:
d 5 d 2 kl (2)
m
where:
d = average inside diameter, in. (or mm),
d = maximum scribed diameter, in. (or mm),
m
k = taper of plug gauge, in. (or mm) of diameter per in. (or mm) of length, and
l = distance from maximum scribed diameter to end of pipe, in. (or mm).
8.4 Report—Report the following information:
8.4.1 When determining conformance to tolerances, report whether the average inside diameter is less than the minimum, greater
than the maximum, or within the allowable limits as indicated by the position of the scribed diameters with respect to the end of
the pipe.
8.4.2 If the actual average inside diameter is required, the result of the calculation in 8.3, as well as the values used in the
calculation, shall be reported. The average inside diameter may also be calculated as described in 10.5.
9. Outside Diameter and Out-of-Roundness Measurement of Roundable Pipe
9.1 Apparatus—Depending on the requirements, the following apparatus shall be used:
9.1.1 Flat-Anvil Micrometer or Vernier Calipers, accurate to 60.001 in. (60.02 mm).
9.1.2 Tapered Sleeve Gauge, for checking conformance to an average outside diameter tolerance of roundable pipe, accurate
within 61 % of its taper and 60.001 in. (60.02 mm) of its diameter. For a given pipe size and tolerance specification, the entrance
diameter shall be the maximum allowable average outside pipe diameter, while the inside diameter at the opposite end shall
correspond to the minimum allowable average outside pipe diameter. To aid rounding, a 45° by ⁄8-in. (3-mm) in. (3 mm) face bevel
shall be provided on the entrance end of the gauge.
9.1.3 Alternatively, a sleeve window gauge, made to the tolerances given in 9.1.2 may be used. The window shall extend beyond
the two scribed marks, which shall represent the minimum and maximum permitted diameters. See Note 3.
NOTE 4—This gauge may also be marked to enable actual average outside diameters to be read directly.
9.1.4 Circumferential Wrap Tape, if the actual value of the average outsid
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