ASTM A733-16(2022)

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: A733 − 16 (Reapproved 2022)
Standard Specification for
Welded and Seamless Carbon Steel and Austenitic Stainless
Steel Pipe Nipples
This standard is issued under the fixed designation A733; 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 2. Referenced Documents
1.1 This specification covers the requirements for welded 2.1 ASTM Standards:
and seamless carbon steel pipe nipples, black and zinc-coated A53/A53M Specification for Pipe, Steel, Black and Hot-
(hot-dip galvanized), and welded and seamless austenitic Dipped, Zinc-Coated, Welded and Seamless
stainless steel pipe nipples in standard steel pipe sizes from ⁄8 A106/A106M Specification for Seamless Carbon Steel Pipe
to 12 in. inclusive, in standard or special lengths. for High-Temperature Service
1.1.1 Welded Carbon Steel—Pipe nipples ordered under A312/A312M Specification for Seamless, Welded, and
these requirements are intended for general uses, as described Heavily Cold Worked Austenitic Stainless Steel Pipes
by Specification A53/A53M or for low-temperature service as A333/A333M Specification for Seamless and Welded Steel
described by Specification A333/A333M. Pipe for Low-Temperature Service and Other Applications
1.1.2 Seamless Carbon Steel—Pipe nipples ordered under with Required Notch Toughness
these requirements are intended for general and special uses, as
2.2 American National Standards Institute Standards:
described by the applicable Specifications A53/A53M and
B1.20.1 Pipe Threads, General Purpose
A106/A106M or for low temperature service as described by
B36.10 Standard for Welded and Seamless Wrought Steel
Specification A333/A333M (see 4.1.1).
Pipe
1.1.3 Austenitic Stainless Steel—Pipe nipples ordered under
B36.19 Standard for Stainless Steel Pipe
these requirements are intended for high-temperature and
general corrosion service, as described by Specification A312/
3. Ordering Information
A312M (see 4.1.2).
3.1 Information items to be considered, if appropriate, for
1.1.4 The text for this specification contains notes or
inclusion in purchase orders are as follows:
footnotes, or both, that provide explanatory material. Such
3.1.1 Quantity (pieces),
notes and footnotes, excluding those in tables, do not contain
3.1.2 Name of material (carbon steel or austenitic stainless
any mandatory language.
steel pipe nipples) (see 4.1.1 and 4.1.2),
1.2 The values stated in inch-pound units are to be regarded
3.1.2.1 Carbon steel applications should identify low-
as standard. The values given in parentheses are mathematical
temperature or high-temperature service, if applicable.
conversions to SI units that are provided for information only
3.1.3 Method of pipe manufacture (continuous-welded,
and are not considered standard.
electric-resistance welded, or seamless) (see 4.1.1),
3.1.4 Type and grade (if stainless steel),
1.3 This international standard was developed in accor-
3.1.5 Finish (carbon steel, black or galvanized),
dance with internationally recognized principles on standard-
3.1.6 Size (nominal and weight class or schedule number as
ization established in the Decision on Principles for the
shown in Table 1, or outside diameter and nominal wall),
Development of International Standards, Guides and Recom-
3.1.7 Length (standard or special, see 4.3),
mendations issued by the World Trade Organization Technical
3.1.8 Specification number,
Barriers to Trade (TBT) Committee.
3.1.9 Certification of compliance, if required, and
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee For referenced ASTM standards, visit the ASTM website, www.astm.org, or
A01.22 on Steel Forgings and Wrought Fittings for Piping Applications and Bolting contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Materials for Piping and Special Purpose Applications. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Sept. 1, 2022. Published October 2022. Originally the ASTM website.
approved in 1976. Last previous edition approved in 2016 as A733 – 16. DOI: Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/A0733-16R22. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A733 − 16 (2022)
TABLE 1 Pipe Nipple Sizes According to Weight of Nominal Pipe
4.3.3 Nipples with lengths up through 12 in. (304.8 mm)
AB
Sizes
long shall have a length tolerance of 6 ⁄16 in. (1.6 mm).
NPS Designator
Nipples over 12 in. long shall have a tolerance of 6 ⁄8 in. (3.2
1 1 3 1
Weight
⁄8 ⁄4 ⁄8 ⁄2 to 6 8 10 12
mm).
C
Standard (Schedule 40) X X X X X X
4.4 End Finish—The ends of the pipe nipples shall be
D C
Extra strong (Schedule X X X X X
chamfered on the outside at an angle of 35 6 10° to the central
80)
axis. (It is the standard practice that the ⁄8-in. (3.2-mm)
Schedule 160 . . . X X X X
Double extra strong . . . X X X X nominal pipe size nipples are not chamfered.) Ends shall be cut
A
A comprehensive listing of standardized pipe dimensions is contained in ANSI reasonably square to the central axis. All burrs on the inside
B36.10 and B36.19.
shall be removed.
B
Continuous-welded pipe is not made in sizes larger than NPS 4 (standard and
extra strong) and larger than NPS 2 ⁄2 (Schedule 160 and double extra strong).
4.5 Galvanized Nipples—Galvanized nipples ordered under
C
NPS 12 standard and extra strong weight pipe do not have designated schedule
this specification shall be made from pipe coated on the inside
numbers.
D
NPS 10 extra strong pipe is Schedule 60, not Schedule 80. and outside by the hot-dip process. Threads and nipple ends are
not galvanized.
5. Sampling and Inspection
5.1 Sampling—Samples of nipples sufficient to determine
3.1.10 Special requirements or exceptions to this specifica-
their conformance with the requirements of this specification
tion.
shall be taken at random for each lot of nipples of the same
3.2 In addition, when material is purchased for agencies of
pipe size, length, and material.
the U.S. Government, it shall conform to the Supplementary
5.2 Inspection—The samples shall be inspected to deter-
Requirements as defined herein when specified in the contract
mine their conformance with the dimensional requirements,
or purchase order.
including thread dimensions and finish of this specification.
4. Requirements
5.3 Gaging Techniques for Male Threads:
4.1 Material and Weight—Pipe nipples covered by this 5.3.1 An NPT working ring gage, in accordance with ANSI
B1.20.1, shall be turned hand tight on the nipple threads. The
specification shall be made from new, hydrostatic-tested or
NDE-tested pipe conforming to the requirements specified in gage shall be tapped or rapped against a solid surface and the
gage again turned hand tight into the thread. Hand tight means
4.1.1 and 4.1.2.
turning the gage until moderate resistance is encountered; no
4.1.1 Carbon Steel—Carbon steel pipe nipples shall be in
excessive force shall be used. After the second tightening
accordance with the following:
operation, the end of the thread should be flush to the gage
Method of Pipe Manufacture Specification
Welded A53/A53M face, plus or minus one turn.
A333/A333M
5.3.2 The reference point for gaging is the end of the thread
Seamless A53/A53M
provided the chamfer is not smaller than the minor diameter of
A106/A106M
A333/A333M
the external thread. When a chamfer on the external thread
exceeds this limit, the reference point becomes the last thread
4.1.2 Austenitic Stainless Steel—Austenitic stainless steel
scratch on the chamfer cone.
pipe nipples shall be in accordance with Specification A312/
A312M. 5.3.3 The usual technique for tapping or rapping the gage is
to swing the end of the fitting with the ring gage attached
4.2 Threads—Pipe nipples shall be threaded on both end
...