
The purpose of Api Specification Pipe And Tube is to provide standards for pipe suitable
for use in conveying gas, water, and oil in both the oil and natural gas industries. Ferropipe
applies this specification to both seamless and welded steel line pipe. Ferropipe supplies pipe with
plain-ends, with ends suitable for threading as well as pipe with ends prepared for use with special
couplings.The American Petroleum Institute specification API 5L addresses seamless and welded steel
line pipe for pipeline transportation systems in the petroleum and natural gas industries. API 5L is
suitable for conveying gas, water, and oil.
Specifications for API 5L adhere to the International Organization for Standardization ISO
3183, standardizing pipeline transportation systems within the materials, equipment and offshore
structures for natural gas, petroleum, and petrochemical industries.
Product Specification Level (PSL) AMERICAN PETROLEUM INSTITUTE has further
divided the grades in accordance with the Product Specifications Levels (PSL) of technical
requirements and therefore developed PSL 1 and PSL 2. Requirements that apply to only PSL 1 or only
PSL 2 are designated. Whereas Requirements that are not designated to a specific PSL apply to both
PSL 1 and PSL 2.
Pipe manufactured as Grade X60 or higher shall not be substituted for pipe ordered as Grade X52 or lower without purchaser approval. followed by the first two digits of the specified minimum yield strength in U.S. Customary units.
The grades covered by this specification are the standard Grades A25, A, B, X42, X46,
X52, X56, X60, X65, X70 and X80; and any intermediate grades (grades that are higher than X42,
intermediate to two sequential standard grades, and agreed upon by the purchaser and manufacturer).
PSL I pipe can be supplied in Grades A25 through X70. PSL 2 pipe can be supplied in Grades B through
X80. Class II (CI II) steel is rephosphorized and probably has better threading properties than
Class I (CI l). Because Class II (CI II) has higher phosphorus content than Class I (CI l), it may
be somewhat more difficult to bend. Pipe manufactured as Grade X60 or higher shall not be
substituted for pipe ordered as Grade X52 or lower without purchaser approval.
Pipe manufactured to ASTM106 Grade A or B are not interchangeable with API 5L. API 5l X
grades have a more specific requirement as compared to API 5L. Rolled raw materials; weld repairs
etc are not allowed due to high yield requirements. Apart from these general requirements, HIC, SOUR
NACE compliance is a must due to combination of High Pressure and High temperature applications with
toughness requirements.
The sizes used here in are dimensionless designations, which are derived from the
specified outside diameter as measured in U.S. Customary units, and provide a convenient method of
referencing pipe size within the text and tables (but not for order descriptions). Pipe sizes 23/8
and larger are expressed as integers and fractions; pipe sizes smaller than 23/8 are expressed to
three decimal places. These sizes replace the “size designation” and the “nominal
size designation” used in the previous edition of this specification. Users of this
specification who are accustomed to specifying nominal sizes rather than 00 sizes are advised to
familiarize themselves with these new size designations used in this specification, especially the
usage in Tables 4, 5, and 6A.
PSL I pipe can be supplied in sizes ranging from 0.405 through 80. PSL 2 pipe can be
supplied in sizes ranging from 4’/2 through 80. Dimensional requirements on threads and thread
gages, stipulations on gagging practice, gage specifications and certification, as well as
instruments and methods for inspection of threads are given in API Standard 5B and are applicable to
threaded products covered by this specification. It includes plain-end, threaded-end, and belled-end
pipe, as well as through-the-flow line (TFL) pipe, and pipe with ends prepared for use with special
couplings.