**White Paper on**

**Materials Specification and Manufacturing**

**Prepared for the Joint Industry Project (JIP) Committee -**

**Alternate Design with Life Cycle Management**

**May 16, 2008**

Prepared by:

Manufacturing and Quality Assurance Team

**Joint Industry Project Committee**

**Alternate Design with Life Cycle Management**

**Steering Committee:**

Alliance Pipeline, Inc. Harold Kraft

Boardwalk Pipeline Partners Frank Maria

CenterPoint Energy Chris Bullock

El Paso Pipeline Group David Bowmaster

Panhandle Energy David Johnson

Spectra Energy Richard Kivela

TransCanada Joe Zhou

Williams Larry Borski

**Committee Support:**

Kiefner and Associates (KAI) Michael Rosenfeld

Process Performance Improvement

Consultants, LLC (P-PIC) John Zurcher

Mark Hereth

Keith Leewis

**Manufacturing and Quality Assurance Team:**

CenterPoint Energy Scott Mundy

Panhandle Energy Liz Rutherford

Spectra Energy Steve Rapp

TransCanada Joe Zhou

Consultant Brian Rothwell

P-PIC Mark Hereth

P-PIC Keith Leewis

**Introduction**

The purpose of this white paper is to address the specific requirements
for materials specification and manufacturing as they relate to the life
cycle management supplement being developed under the auspices of ASME
B31.8. The specific requirements (***in bold in the text**)* described
in this white paper address the operation of pipeline systems with
design factors greater than the conventional basis, up to 80% of SMYS in
Class 1, 67% in Class 2, and 56% in Class 3. This white paper
supplements the requirements of existing reference standards to address
any incremental manufacturing threats at these higher design factors.

In the context of a life cycle management approach, it is anticipated
that operators will develop and apply a comprehensive quality management
system (QMS), that addresses all phases of the material procurement,
shipping, construction and commissioning process. The way in which such
a system is typically used to interact with and manage supplier
manufacturing and quality control practices (the materials and
manufacturing quality management program) is described in later
sections.

One of the net effects of the use of increased design factors is to
allow for thinner wall pipe. Purchaser material and manufacturing
quality management programs must ensure that any inclusions and
laminations from the solidification process will not adversely affect
the final pipe performance, and assure that the pipe dimensional
tolerances such as out-of-roundness and straightness will not adversely
affect field welding. The white paper defines how pipe properties,
dimensional conformance and freedom from injurious imperfections are
managed by a materials and manufacturing quality management program.
Materials and manufacturing quality management programs draw upon
international consensus-based standards in combination with mill and
source-specific specifications, quality control measures used by the
pipe mill and quality assurance used by the purchaser. The quality
management program comprises four steps:

1.  Pipe manufacturing mill qualification

2.  Pipe standard, specifications and contracting agreements

3.  Pipe manufacturing procedure specification review and agreement

4.  Surveillance and auditing

The purchaser first engages in a technical evaluation of the mill to
ensure that the mill is qualified to produce pipe to the purchaser's
specifications. The purchaser will establish a pipe specification
knowing the requirements of the project for which the pipe is being
procured. The mill and purchaser engage in the development of, and
agreement upon, a manufacturing procedure specification (MPS) that
establishes the materials specification to standards and the purchaser's
additional requirements and manufacturing procedures and quality
control/quality assurance (QA/QC) practices. The mill knows best how to
source the steel, roll and weld pipe to meet the performance parameters
required by the purchaser. The MPS sets out the types and frequencies of
inspections and how exceptions are to be dealt with. The MPS is designed
to locate issues before they become problems and minimize exceptions.

The applicability of the Life Cycle Management alternative under ASME
B31.8 to an existing pipeline system will be evaluated based on
reference standards (such as API 5L) and any additional purchaser
requirements previously negotiated and contracted to be in place at the
time of procurement of materials.

**Background**

The base reference standard for line pipe is American Petroleum
Institute Specification 5L, Specification for Line Pipe (API 5L).
***Line pipe must be manufactured according to API 5L, product
specification level 2 (PSL 2), including the supplementary requirements
(SR) for maximum operating pressures, as well as maximum and minimum
operating temperatures for the pipeline system. In general, the
metallurgical, chemical and dimensional requirements of API 5L, PSL 2
are appropriate for operation at the higher design factors defined
above.*** Exceptions and additional requirements are identified and
described in the remainder of this white paper. The applicable version
of API 5L as of the publication of this white paper is the 43^rd^
edition. The 44^th^ edition becomes effective on October 1, 2008.

Pipe fittings, valves and flanges, associated with line pipe and main
line block valves, will be designed and purchased in accordance with
applicable reference standards or their equivalent, already incorporated
within 49 CFR 192 but included for completeness, and set forth below.
The referenced standards may be supplemented by the operator's
supplemental requirements to ensure the materials meet the minimum
engineering design specifications. In all cases, the valves and flanges
will be ANSI Class 600 for pressures up to and including 1,480 psig, and
ANSI 900 for pressures up to 2,200 psig. Valves will be manufactured in
accordance with API 6D. High-test flanges will be manufactured in
accordance with MSS SP-44 and normal flanges in accordance with ASME
B16.5. Small pipe fittings will be manufactured in accordance with ASME
B16.9 and large fittings with MSS SP-7. All of these materials will be
pressure tested in accordance with the applicable standards.

***The pipe steel must be a low-carbon, high-strength low-alloy
material. The skelp/plate must be micro alloyed, fine grain, fully
killed steel with calcium treatment and produced by continuous
casting.***

The steel rolling and pipe mills have the knowledge to ensure the pipe
will meet the purchaser's required properties. Different indicators are
used throughout the processes to minimize exceptions and to ensure all
of the pipe meets the final strength and toughness requirements. The use
of micro-alloying is demonstrated by the presence of controlled amounts
of one or more of the elements titanium, vanadium and niobium. Aluminum
present at 0.05% or less, together with the microalloying elements,
promotes a fine-grained steel. Only killed steels can be continuously
cast and the residual levels of aluminum, at \< 0.050% and silicon at \<
0.36% demonstrate that the steel is fully killed. The trace levels of
calcium, approximately 0.005%, confirm calcium treatment but really
calcium treatment is only one way to ensure that there was adequate
desulphurization and deoxidation to ensure the micro alloys remain
available for grain refinement and are not lost to the slag or as macro
inclusions.

With respect to carbon equivalents, the consensus standard API 5L
establishes specifications for maximum carbon equivalents using the
Ito-Bessyo formula (Pcm formula) for varying grades and wall thicknesses
of steel pipe. The JIP work group considered more stringent limitations
than those in API 5L but could find no technical justification for doing
so. INGAA supports use of the limits as expressed in API 5L, absent any
other information to justify differing limits. The JIP work group
recommends that limits established in API 5L be adopted, that is, ***the
carbon equivalents for low carbon steels containing 0.12% or less carbon
are restricted to Pcm \< 0.25% and medium carbon steel fabrications
restricted CE~IIW~ \< 0.43%***. These restrictions are known to avoid
the need for preheating before welding.

The JIP work group and the Steering Team considered inclusion of the
compressor stations, as well as metering and regulation stations, within
the life cycle management alternative for new pipeline systems. However,
JIP members have found that in most instances, the benefits of the
higher design factor for new systems are generally not justified
relative to the total cost. This is not the case for existing pipeline
systems, and special considerations for existing systems are addressed
at the end the white paper.

**Material and Manufacturing Quality Management**

Materials and manufacturing quality management programs draw upon
international consensus-based standards, such as API 5L, in combination
with mill and source-specific specifications, quality control measures
used by the pipe mill and quality assurance used by the purchaser.

API 5L starts with materials to be made into pipe. The JIP work group
believes that additional requirements are warranted for new line pipe
source materials, generally slabs. Specifically***, (T)he purchaser
(operator) will purchase pipe using a material and manufacturing quality
management program.*** The objective of the plan is to ensure that the
source material, when rolled into plate or coil and formed into pipe,
will achieve the desired mechanical and toughness properties of API 5L,
together with company- and project-specific requirements, with a minimum
of process-related and technical issues.

The quality management program comprises four steps:

1.  Pipe manufacturing mill qualification

2.  Pipe standard, specifications and contracting agreements

3.  Pipe manufacturing procedure specification review and agreement

4.  Surveillance and inspection

**Pipe Manufacturing Mill Qualification**

The purchaser engages in a technical evaluation of the mill to ensure
that the mill is qualified to produce pipe to the purchaser's
specifications. Qualification of manufacturing facilities extends, as
deemed necessary, to steelmaking and skelp rolling, as well as to pipe
manufacture. The pipe manufacturer, if qualified, is normally deemed to
be so conditional on supply of steel and skelp by the qualified
suppliers.

It is important to recognize that each manufacturing mill is somewhat
unique and there is no single basis for establishing prescriptive
control measures for manufacture of pipe. The pipe mill considers the
purchaser's specifications in the context of its manufacturing
capabilities and selects source materials that assure the purchaser's
specifications are achieved.

The respective manufacturing plants are subjected to evaluation for
qualification through implementation of a documented program of
assessment of factors including, but not limited to, the following:

> i\) steel source, including steelmaking method, heat size, deoxidation
> practice, inclusion shape control practices, alloying elements, and
> casting method;
>
> ii\) target chemistries and chemical limits for all elements
> referenced in API 5L, as well as all elements referenced under the
> purchaser's pipe specification, as applicable to pipe of each
> diameter, wall thickness, and material grade;
>
> iii\) plate or coil rolling method as applicable and specific rolling
> mill practices, including typical reduction schedules as available,
> final finishing temperatures as available, and facilities for on-line
> accelerated cooling, coiling and in-line or post-forming heat
> treatment;
>
> iv\) skelp inspection procedures;
>
> v\) details of pipe forming procedures;
>
> vi\) plant limitations on wall thickness, diameter, and material
> grade;
>
> vii\) laboratory test equipment present at the manufacturing plant for
> testing of material properties for the order;
>
> viii\) typical welding parameters and consumable combinations for
> longitudinal, helical, skelp end, repair, and circumferential jointer
> welds as applicable;
>
> ix\) method and typical amount of cold expansion as applicable;
>
> x\) normal mill control tolerances and frequency of assessment and
> recording for all specificied dimensions for pipe;
>
> xi\) a description of the quality organization applicable to
> steelmaking, skelp rolling and pipe manufacturing, including
> identification of reporting practices, verification mechanisms to
> assure product traceability, responsibility for customer contact
> related to commercial and quality matters, and details of formal
> registration of quality management systems referenced in API 5L;
>
> xii\) nondestructive inspection procedures utilized for specification
> compliance and for production control, as applicable to skelp, pipe
> body, pipe ends, and welds;
>
> xiii\) yard handling, storage, and shipping procedures, including
> drawings of proposed methods of stacking and securing pipe for
> shipment; and
>
> xv\) facilities available for the Purchaser and his representatives
> for inspection and review of documentation.

Evaluation for qualification is carried out for each pipe mill location,
including skelp source materials. A similar methodology is implemented
for evaluation of coating application facilities.

**Pipe Standard, Specification and Contracting Agreements**

The purchaser's pipe specification serves as the defining document used
to contract for purchase of pipe. The purchaser specifies the adherence
to the standard, API 5L, and in the case of pipe ordered for operation
under life cycle management, it is expected that the purchaser will
specify that provisions of API 5L, product specification level 2, are
required.

The purchase agreement or purchase order provides terms and conditions
that establish the contracting requirements to assure that the pipe as
received meets the purchaser specifications***. A purchaser will only
enter into an agreement with a pipe mill when the process described
above has qualified the mill.*** The purchase order terms and conditions
include provisions for holding and ultimately rejecting pipe not
conforming to the purchase order. The purchaser order also provides
access to the manufacturing mills for surveillance and inspection.

**Pipe Manufacturing Procedure Specification Review and Agreement**

The applicable manufacturing procedure specification is specified in the
terms and conditions of the purchase order. Specification review
meetings (also referred to as pre-production meetings) are held for all
pipe orders emanating from project-specific pipe mill rollings, in order
to clarify and reach agreement on project-specific technical matters,
thereby minimizing specification misinterpretation and misunderstandings
during pipe production.

The MPS review can occur over multiple days and entails a review of each
particular requirement in the purchaser's pipe specification. In
addition, the MPS review also entails a discussion and agreement upon
the conditions to be used by the mill in each step of the manufacturing
process to assure conformance with the pipe specification. Typically, a
Quality Assurance Plan (QAP) is prepared detailing the critical
operating parameters, specifications and acceptance criteria. Authorized
personnel in the mill and for the purchaser sign off on the QAP.

Using a pre-defined set of agenda items, a documented summation of
agreements evolves. This summation of agreements includes a confirmation
of order quantities, confirmation of steel and skelp sources,
finalization of technical agreements addressing pipe manufacturer and
coating applicator requests for clarification or deviation from
specification requirements, review of applicable NDT and inspection
systems, and finalization of scheduling deadlines to accommodate timely
on-site delivery to designated stockpile sites. The summation of
agreements, as formally agreed by both the purchaser and the vendor,
forms a part of the pipe purchase order.

**Surveillance and Inspection**

Surveillance and inspection are essential elements of the materials and
manufacturing quality management program. Inspection is the process of
ensuring that the mill is executing manufacturing in conformance with
the MPS and the QAP. Inspection can be conducted by the purchaser but is
typically contracted to a third party. The third party assigns personnel
to locations in the mill to monitor execution, review documentation and
take independent measurements to assure conformance with the MPS and
QAP. Non-conformances are identified and raised with mill supervision to
be addressed. Pipes identified or suspected as being non-conforming are
pulled from the manufacturing process until their conformance can be
confirmed or they are rejected as per the purchase order. Mill
supervision investigates the cause of nonconforming pipe, determines
whether it is an isolated instance or a systematic problem, and in the
later case formulates a corrective action plan.

Surveillance is an additional step of quality assurance in which the
purchaser makes personnel available on a periodic basis to oversee the
execution of the MPS and QAP and to audit the inspection process.

**Specific Manufacturing Control Measures Considered By The JIP Work
Group**

The operator's pipe specification specifies steel properties and the
mill selects the chemical formulations that are designed to ensure the
slab producer, skelp mill and the pipe mill achieve the desired final
properties in the finished pipes. Most alloying elements must fall
within compositional limits that, together with the controlled skelp
production and pipe manufacturing process, are known to lead to the
appropriate mechanical properties. Solidification control during
continuous casting minimizes centerline segregation and lamination from
refractory and slag entrapment.

Centerline segregation and lamination in the pipe body or pipe ends, if
it extends into the weld preparation, can adversely affect weld quality
and may promote girth weld cracking. In particular, carbon, oxygen,
sulfur and phosphorus are controlled to promote weldability and ensure
toughness, and the controlled rolling (and accelerated cooling/strip
coiling where applicable) using advanced thermo-mechanical parameters,
and micro-alloying elements are used to assure the fine grain size and
precipitation hardening effects which compensate for any loss of
strength, due to the reduced carbon contents typically used in modern
line-pipe steels.

It is important to recognize that API 5L provides performance-based
requirements to address the outcomes of centerline segregation, or
failure of the source material to meet the metallurgical and dimensional
properties of the operator's pipe specification and API 5L. The
operator, the pipe mill and source mill must balance the use of quality
control measures and the potential for out-of-specification pipe to be
formed. This is not best achieved by the imposition of a single simple
prescriptive approach unrelated to the negotiated MPS. Delays always
lead to increased cost, and these will be incurred by improperly
imposing production constraints.

Even considering the performance-based requirements set forth in API 5L,
the JIP Work Group members recommend that the purchaser require that
specific slab mill inspections, such as macro-etch testing, be included
in the applicable MPS. Macro-etch testing is a valuable quality control
method to be applied by the mill. While the work group recommends
specifying that the tests be conducted, the frequency and acceptance
criteria are to be agreed upon between the purchaser and the mill.

The pipe mill must include a comprehensive plate/coil and pipe mill
inspection program to check for surface defects and inclusions that can
be injurious to the integrity of the pipe. This program can be conducted
on plate or rolled pipe (body and all ends) ultrasonic testing (UT)
inspection program using as a basis, guidelines in ASTM A578 to check
for imperfections such as laminations. Alternatively, the mill may
conduct full-body UT of the pipe. This entails the use of a single
transducer oscillating back and forth across the surface. The basis of
either approach is to assure that the inspection finds defects that
exceed a certain minimum size in the body of the plate or pipe, and
provides coverage for 100 percent of the pipe ends back a specified
length. The work group recommends that the performance criteria set
forth in ASTM 578 be used for plate inspection and as a basis for
establishing criteria for full-body UT.

The pipe weld seam must meet the minimum requirements for tensile
strength as specified in API 5 for the appropriate pipe grade
properties. A pipe weld seam hardness test using Vickers hardness
testing of a cross-section from the weld seam will be carried out across
the plate, HAZ, and weld material volumes and must be performed on one
length of pipe from each heat. API 5L requires that the pipe weld seam
must be 100 percent UT or x-ray inspected to ensure there are no
defects. In addition API 5L requires that pipe ends be non-destructively
inspected by either UT or x-ray, to ensure that there are no injurious
laminations or inclusions interacting the weld volume.

The JIP work group considered the use of a threshold value for hardness,
such as 280 Vickers Hardness (Hv 10). While API 5L does provide such a
threshold value for sour gas service, it does not provide a single,
fixed value for the gas service addressed under 49 CFR 192; that is the
transportation of non-corrosive gases. The work group recommends that
the pipe mill and the purchaser should establish a hardness maximum in
the manufacturing procedure specification and quality assurance plan.

The JIP work group examined hydrostatic testing practices in modern
mills around the world and found that most operators specify a
hydrostatic test of 95 percent of the specified minimum yield strength
(SMYS) for a duration of 10 seconds. API 5L in the forty-third edition
and for a number of years has specified a test to 90 percent of SMYS for
10 seconds[^1]. The members of the JIP work group discussed test
pressure and duration and reached the following conclusions. Testing to
95 percent of SMYS is appropriate as long as the current provisions that
allow for end-loading compensation as per Appendix K are applicable. In
addition, the addition of time beyond the 10 seconds stipulated in API
5L does not provide quantifiable value to the test and increasing the
duration could impact the productivity of the pipe mills.

The JIP work group recommends, "***A hydrostatic test will be conducted
in the pipe mill at a pressure of at least 95% of SMYS, for a duration
of 10 seconds.***"

The JIP work group considered the use of a ratio of the diameter over
the nominal wall thickness, referred to as D/t, to address the threat of
damage during construction, as well as atypical loads and mechanical
damage during operation of the pipeline. The work group believes that
while consideration of the relationship between wall thickness relative
to pipe diameter is important, there is no hard and fast threshold that
applies under all circumstances. D/t limitations are particularly
inappropriate for higher yield strength pipe. For pipe grades X-80 and
above, the D/t ratios may exceed 100 to 1. Ovality and denting issues
can be managed for these higher D/t pipelines, and for that matter any
pipe under this regulation through the construction practices proposed
by PHMSA in 192.328(a)(1), Quality Assurance (during construction), and
by provisions in the existing ASME code that relate to analyses of
instantaneous and sustained loads during operation (ASME B31.8,
Paragraph 833.4).

**Special Considerations for Existing Facilities**

Existing pipeline systems may require compressor and meter stations to
be up-rated to be able to benefit from use of the higher design factors.
There is a sound basis for this in the existing code and from earlier
versions of ASME B31.8. Prior to 1953, the ASME code allowed for a
design factor of 0.64 for stations. This factor was based on the use of
a safety factor of 80 percent applied to a mill test conducted at 80
percent. The ASME natural gas committee lowered the station design
factor to 0.5 in 1954, recognizing the demand to rapidly build pipeline
infrastructure in the Post-WW II era and permit construction without
requiring any additional engineering assessment. Clearly, when the
operator can apply greater diligence and conduct a comprehensive and
systematic evaluation of the suitability of materials for higher
pressures, the historical basis is appropriate. In addition, there are
stations constructed prior to 1970 that have been "grandfathered", using
a 0.64 design factor.

The JIP work group recommends that ***the station design factor for
existing facilities be established at 0.56.*** The work group did
consider adoption of the historical 0.64 factor but recognized that as a
practical matter, the eleven percent increase comparable to that of the
line pipe is all that is needed to ensure all components can withstand
the new pressure; thus the reason for adoption of 0.56.

**Compressor Station Evaluation**

***The operator must conduct an evaluation of the compressor station
equipment and piping to determine the rating of each component, to
ensure that the station can be operated safely and reliably at pressures
up to the desired MAOP.***

The evaluation will begin with an analysis of the original design basis
for each component, including valves, valve actuators, fittings,
flanges, gaskets and bolting, compression, pig traps and associated
piping, pressure regulators and meters. Components not meeting the
requirements for design at the higher pressure must be evaluated for
possible re-rating under applicable pressure vessel or other code, and
where re-rating is infeasible, the component must be replaced.

**Meter Station Evaluation**

***The operator must conduct an evaluation of the meter station
equipment to determine the rating of each component, to ensure the
station can be operated safely and reliably at pressures up to the
desired MAOP.***

The evaluation will begin with an analysis of the original design basis
for each component, including valves, valve actuators, fittings,
flanges, gaskets and bolting and associated piping, pressure regulators
and meters. Components not meeting the requirements for design at the
higher pressure will be evaluated for possible re-rating under
applicable pressure vessel or other code, and where re-rating is
infeasible, the component must be replaced.

[^1]: Even the Forty-Fourth edition of API 5L, effective October 1, 2008
    retains the 90% SMYS for at least 10 seconds for large diameter
    pipe.