Update on the API
Work Group Activities
on Pipe Markings
API Pipe Grades
Grade B, X42, X52, X60, X65, X70, X80
API Pipe Grades
Grade B, X42, X52, X60, X65, X70, X80
And Two
Product Specification Levels
API Pipe Grades
Grade B, X42, X52, X60, X65, X70, X80
And Two
Product Specification Levels
PSL 1 and PSL 2
API Grade X60, PSL 2
Yield Strength Range 60.2 – 81.9 ksi
API Grade X65, PSL 2
Yield Strength Range 65.3 – 87 ksi
API Grade X70, PSL 2
Yield Strength Range 70.3 – 92.1 ksi
60
62
64
66
68
70
72
74
76
78
Yield Strength in ksi
80
82
84
86
88
90
92
94
Historically, it has been a common
practice to apply dual-grade
markings at the lower end of the
grade spectrum
The most common dual grade
product has always been
Grade B/X42
Other common dual-grade items are:
-X42/X46
-B/X42/X46
-X42/X52
API Specification 5L Provides Only Minimal
Guidelines regarding dual markings for Line Pipe:
- Pipe manufactured as Grade X60 (415) or
higher shall not be substituted for pipe ordered
as Grade X52 (360), or a lower grade, without
the purchaser's approval.
- API Spec 5L, Annex N specifically allows
marking pipe with comparable specifications.
This allows pipe to have API markings as well
as CSA or ISO designations
In the last few years, pipe mills have
seen an increased number of
requests for application of dual-grade
markings in upper grades.
- X60 / X65
-X65 / X70
- X60 / X65 / X70
-X70 / X80
API Grade X52, PSL 1
Yield Strength Minimum 52.6 (no maximum for PSL 1)
API Grade X60, PSL 1
Yield Strength Minimum 60.2 (no maximum for PSL 1)
API Grade X65, PSL 1
Yield Strength Minimum 65.3 (no maximum for PSL 1)
API Grade X70, PSL 2
Yield Strength Range 70.3 – 92.1 ksi
API Grade X80, PSL 2
Yield Strength Range 80.5 – 102.3 ksi
60
62
64
66
68
70
72
74
76
78
80
82 84
Yield Strength in ksi
86
88
90
92
94
96
98 100 102 104
There have been reports of pipe being
stenciled and certified as follows:
X52 PSL 1, X60 PSL1, X65 PSL 1,
X70 PSL 2, X80 PSL 2
API Grade X60, PSL 2
Yield Strength Range 60.2 – 81.9 ksi
API Grade X65, PSL 2
Yield Strength Range 65.3 – 87 ksi
API Grade X70, PSL 2
Yield Strength Range 70.3 – 92.1 ksi
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
92
94
API 1104 for Field Welding of Line Pipe
contains the following restrictions on welding
procedure qualification:
Welding Procedures shall be qualified within the
following grade ranges:
< X42
X46, X52, X56 (including intermediate grades)
For X60 & above, each grade is qualified
individually
One pipeline operator reported that they were laying a line
of X65 PSL 2 pipe. They were using X65 / X70 dual grade
pipe in the line. They were audited by the pipeline
regulatory agency (PHMSA) and all of their welding
documentation referenced qualification of API Grade X65,
PSL 2. Since the pipe was X65 / X70 and each grade is
required to be qualified separately, the auditor would not
accept the X65 documentation.
Proposal Issued for Vote to the API Membership for
requirements to be added to API Spec 5L:
Marking of Pipe to Multiple Grades:
Marking of pipe to multiple grades is permitted only by agreement between the
purchaser and the manufacturer within the following guidelines:
- Pipe may have multiple markings within the following grade ranges:
< X42
X46, X52, X56 (including intermediate grades)
For X60 & above, marking of multiple grades is prohibited
- The manufacturer is responsible to assure that the pipe conforms to
all requirements of each of the certified grades. This allows pipe to be
used as any of the grades individually.
- Pipe shall be marked to only one PSL level.
- Where pipe is marked to multiple grades, a single certification
document shall be issued referencing the grade combination as
marked on the pipe. The certification document may contain a specific
statement that pipe conforms to each grade individually.
- Pipe shall only be re-graded and re-marked under the
manufacturer’s control. Certificates for re-graded pipe may only be
issued by the pipe manufacturer.
The results of the ballot were surprising. Overall, the votes
were for acceptance of the new requirement. However, as
expected, there were a number of negative votes.
The biggest objection was that the current proposal
restricts dual-grading of X42 / X52, which has been a
common industry practice.
API requires that negative ballots must be resolved
before the item can go forward.
The work on this item is currently on-going.
A new edition of API Specification 5L will probably be
issued early 2011. It is the intent of the work group to have
this item finalized and ready for publication in the next
edition of the Specification.
Before that can happen, all negative votes have to be
resolved and the exact wording of the requirement will
need to be finalized.
The final version will be reviewed by members of the API
1104 group as well as the API Quality group to assure
compliance with those requirements.
Marking of Pipe to Multiple Grades:
Marking of pipe to multiple grades is permitted only by agreement between the
purchaser and the manufacturer within the following guidelines:
- Pipe may have multiple markings within the following grade ranges:
< X42
X46, X52, X56 (including intermediate grades)
For X60 & above, marking of multiple grades is prohibited
- The manufacturer is responsible to assure that the pipe conforms to
all requirements of each of the certified grades. This allows pipe to be
used as any of the grades individually.
- Pipe shall be marked to only one PSL level.
- Where pipe is marked to multiple grades, a single certification
document shall be issued referencing the grade combination as
marked on the pipe. The certification document may contain a specific
statement that pipe conforms to each grade individually.
- Pipe shall only be re-graded and re-marked under the
manufacturer’s control. Certificates for re-graded pipe may only be
issued by the pipe manufacturer.