ASME BPVC.VIII.1-2025

SUBSECTION A
GENERAL REQUIREMENTS
PART UG
GENERAL REQUIREMENTS FOR ALL METHODS OF
CONSTRUCTION AND ALL MATERIALS
UG-1 SCOPE
The requirements of Part UG are applicable to all pressure
vessels and vessel parts and shall be used in conjunction
with the specific requirements in Subsections B, C,
and D and the Mandatory Appendices that pertain to
the method of fabrication and the material used.
MATERIALS
UG-4 GENERAL
(a) Material subject to stress due to pressure shall conform
to one of the specifications given in Section II, Part D,
Subpart 1, Tables 1A, 1B, and 3, including all applicable
notes in the tables, and shall be limited to those that are
permitted in the applicable Part of Subsection C, except
as otherwise permitted in UG-9; UG-10; UG-11; UG-15;
Part UCS; Subsection D, Part UIG; and the Mandatory Appendices.
Material may be identified as meeting more
than one material specification and/or grade, provided
the material meets all requirements of the identified material
specification(s) and/or grade(s) [see UG-23(a)].
(b) Material for nonpressure parts, such as skirts, supports,
baffles, lugs, clips, and extended heat transfer surfaces,
need not conform to the specifications for the
material to which they are attached or to a material specification
permitted in this Division, but if attached to the
vessel by welding shall be of weldable quality [see
UW-5(b)]. The allowable stress values for material not
identified in accordance with UG-93 shall not exceed
80% of the maximum allowable stress value permitted
for similar material in Subsection C.
(c) Material covered by specifications in Section II is
not restricted as to the method of production unless so
stated in the specification, and so long as the product
complies with the requirements of the specification.
(See UG-85.)
(d) Materials other than those allowed by the rules of
this Division shall not be used. Data for new materials
shall be submitted to and approved by the ASME Boiler
and Pressure Vessel Committee on Materials in accordance
with Section II, Part D, Mandatory Appendix 5.
(e) Materials outside the limits of size and/or thickness
given in the title or scope clause of the specifications given
in Section II, and permitted by the applicable Part of
Subsection C, may be used if the material is in compliance
with the other requirements of the specification,6 and no
size or thickness limitation is given in the stress tables. In
those specifications in which chemical composition or
mechanical properties vary with size or thickness, materials
outside the range shall be required to conform to
the composition and mechanical properties shown for
the nearest specified range.
(f) It is recommended that the user or the user’s designated
agent ensure that materials used for the construction
of the vessels will be suitable for the intended
service with respect to retention of satisfactory mechanical
properties, and resistance to corrosion, erosion, oxidation,
and other deterioration during their intended
service life. See also informative and nonmandatory guidance
regarding metallurgical phenomena in Section II,
Part D, Nonmandatory Appendix A.
(g) When specifications, grades, classes, and types are
referenced, and the material specification in Section II,
Part A or Part B is a dual‐unit specification (e.g.,
SA-516/SA-516M), the design values and rules shall be
applicable to either the U.S. Customary version of the material
specification or the SI unit version of the material
specification. For example, when SA-516M Grade 485 is
used in construction, the design values listed for its
equivalent, SA-516 Grade 70, in either the U.S. Customary
or metric Section II, Part D (as appropriate) shall be used.
(h) When the rules of this Division require the use of
material physical properties, these properties shall be
taken from the applicable tables in Section II, Part D,
UG-1 – UG-4 ASME BPVC.VIII.1-2025
8

Subpart 2. If the applicable tables in Section II, Part D,
Subpart 2 do not contain these properties for a permitted
material or do not list them within the required temperature
range, the Manufacturer may use other authoritative
sources for the needed information. The Manufacturer’s
Data Report shall note under “Remarks” the property values
obtained and their source.
NOTE: If material physical properties are not listed, the Manufacturer
is encouraged to bring the information to the attention of the
ASME Committee on Materials (BPV Section II) so that the data
can be added in Section II, Part D, Subpart 2.
UG-5 PLATE7
Plate used in the construction of pressure parts of pressure
vessels shall conform to one of the specifications in
Section II for which allowable stress values are given in
the tables referenced in UG-23, except as otherwise provided
in UG-4, UG-10, UG-11, and UG-15.
UG-6 FORGINGS
(a) Specifications and maximum allowable stress values
for acceptable forging materials are given in the
tables referenced in UG-23. (See Part UF for forged
vessels.)
(b) Bar [as defined in UG-14(a)] that is forged independent
of the material specification to which it is certified
may be used only within the limitations of UG-14.
(c) Forgings certified to SA-105, SA-181, SA-182,
SA-350, SA-403, and SA-420 may be used as tubesheets
and hollow cylindrical forgings for pressure vessel shells
that otherwise meet all the rules of this Division, provided
the following additional requirements are met:
(1) Forgings certified to SA-105 or SA-181 shall be
subject to one of the austenitizing heat treatments permitted
by these specifications.
(2) One tension test specimen shall be taken from
each forging weighing more than 5,000 lb (2 250 kg).
The largest obtainable tension test specimen as specified
by the test methods referenced in the applicable specification
shall be used. Except for upset-disk forgings, the longitudinal
axis of the test specimen shall be taken parallel
to the direction of major working of the forging. For
upset-disk forgings, the longitudinal axis of the test specimen
shall be taken in the tangential direction. When
agreed to by the Manufacturer, and when not prohibited
by the material specification, test specimens may be machined
from specially forged test blocks meeting the provisions
provided in SA-266 or other similar specifications
for large forgings.
(3) For quenched and tempered forgings weighing
more than 10,000 lb (4 500 kg) at the time of heat treatment,
two tension test specimens shall be taken from
each forging. These shall be offset 180 deg from each
other, except that if the length of the forging, excluding
test prolongations, exceeds 12 ft (3.7 m), then one specimen
shall be taken from each end of the forging.
UG-7 CASTINGS
Cast material may be used in the construction of pressure
vessels and vessel parts. Specifications and maximum
allowable stress values for acceptable casting
materials are given in the tables referenced in UG-23.
These allowable stress values shall be multiplied by the
applicable casting quality factor given in UG-24 for all materials
except cast iron.
UG-8 PIPE AND TUBES
(a) Pipe and tubes of seamless or welded8 construction
conforming to one of the specifications given in Section II
may be used for shells and other parts of pressure vessels.
Allowable stress values for the materials used in pipe and
tubes are given in the tables referenced in UG-23.
(b) Integrally finned tubes may be made from tubes
that conform in every respect with one of the specifications
given in Section II. The requirements of (1), (2),
(3), and (5) do not apply to tubes produced in accordance
with a Section II integrally-finned material specification.
These tubes may be used under the following conditions:
(1) The tubes, after finning, shall have a temper or
condition that conforms to one of those provided in the
governing specifications, or, when specified, they may
be furnished in the “as‐fabricated condition” where the
finned portions of the tube are in the cold worked temper
(as‐finned) resulting from the finning operation, and the
unfinned portions in the temper of the tube prior to
finning.
(2) The maximum allowable stress value for the
finned tube shall be that given in the tables referenced
in UG-23 for the tube before finning except as permitted
in (3) below.
(3) The maximum allowable stress value for a temper
or condition that has a higher stress value than that
of the tube before finning may be used, provided that qualifying
mechanical property tests demonstrate that such a
temper or condition is obtained and conforms to one of
those provided in the governing specifications in Section
II, and provided that allowable stress values have been established
in the tables referenced in UG-23 for the tube
material used. The qualifying mechanical property tests
shall be made on specimens of finned tube from which
the fins have been removed by machining. The frequency
of tests shall be as required in the unfinned tube
specification.
(4) The maximum allowable internal or external
working pressure of the tube shall be based on the root
diameter and the minimum wall of the finned section,
or the outside diameter and wall of the unfinned section
together with appropriate stress values, whichever results
in the lower maximum allowable working pressure.
Alternatively, the maximum allowable external pressure
for tubes with integral fins may be established under
the rules of Mandatory Appendix 23.
ASME BPVC.VIII.1-2025 UG-4 – UG-8
9with such other markings as will serve to identify the particular
parts with accompanying material identification.
The Manufacturer of the completed vessel shall be satisfied
that the part is suitable for the design conditions specified
for the completed vessel in accordance with the
rules of this Division.
(c) Cast, Forged, Rolled, or Die Formed Standard Pressure
Parts That Comply With an ASME Product Standard,
Either Welded or Nonwelded
(1) These are pressure parts that comply with an
ASME product standard accepted by reference in
UG-44(a). The ASME product standard establishes the basis
for the pressure–temperature rating and marking unless
modified in UG-44(a).
(2) Flanges and flanged fittings may be used at the
pressure–temperature ratings specified in the appropriate
standard listed in this Division.
(3) Materials for standard pressure parts shall be as
follows:
(-a) as permitted by this Division or
(-b) as specifically listed in the ASME product
standard
(4) When welding is performed it shall meet the
following:
(-a) the requirements of UW-26(a), UW-26(b),
and UW-26(c) and UW-27 through UW-40, or;
(-b) the welding requirements of ASME specification
SA-234.
(5) Standard pressure parts as identified in UG-11(c)
do not require inspection, identification in accordance
with UG-93.1 or UG-93.2, or Partial Data Reports, provided
the requirements of UG-11(c) are met.
(6) If postweld heat treatment is required by the
rules of this Division, it may be performed either in the location
of the parts manufacturer or in the location of the
Manufacturer of the vessel to be marked with the Certification
Mark.
(7) If radiography or other volumetric examination is
required by the rules of this Division, it may be performed
at one of the following locations:
(-a) the location of the Manufacturer of the completed
vessel
(-b) t h e l o c a t i o n of the pressure p a r t s
manufacturer
(8) Parts made to an ASME product standard shall be
marked as required by the ASME product standard.
(9) The Manufacturer of the completed vessels shall
have the following responsibilities when using standard
pressure parts that comply with an ASME product

ASME BPVC.IX-2025 ARTICLE 5
TESTS, INSPECTION, AND MARKING
HG-500 PROOF TESTS TO ESTABLISH DESIGN
PRESSURE
HG-501 General
(a) The design pressure for pressure parts of boilers for
which the strength cannot be computed with a satisfactory
assurance of accuracy shall be established in accordance
with the requirements of this paragraph, using one of the
test procedures applicable to the type of loading and to the
material used in its construction.
(b) The tests in these paragraphs may be used only for
the purpose of establishing the design pressure of those
elements or component parts for which the thickness
cannot be determined by means of the design rules
given in the Code. The design pressure of all other
elements or component parts shall not be greater than
that determined by means of the applicable design rules.
HG-501.1 Types of Tests. Provision is made for two
types of tests for determining the internal design
pressure:
(a) tests based on yielding of the part to be tested; these
tests are limited to materials with a ratio of minimum
specified yield to minimum specified ultimate strength
of 0.625 or less. If a proof-tested part shows no evidence
of permanent yielding per HG-502.1 and HG-502.2, it may
be marked with the Certification Mark.
(b) tests based on bursting of the part. The Certification
Mark shall not be applied on the part proof tested under
the burst-test provisions.
HG-501.2 Retests. A retest shall be allowed on a
duplicate pressure part if errors or irregularities are
obvious in the test results.
HG-501.3 Precautions. Safety of testing personnel
should be given serious consideration when conducting
proof tests, and particular care should be taken during
the conducting of bursting tests per HG-502.3.
HG-501.4 Pressure Application.
(a) Previously Applied. The pressure parts for which the
design pressure is to be established shall not previously
have been subjected to a pressure greater than 11∕2 times
the desired or anticipated design pressure.
(b) Application. In the procedures given in HG-502.1 for
the strain measurement test and HG-502.2 for the displacement
measurement test, the hydrostatic pressure
in the pressure part shall be increased gradually until
approximately one-half the anticipated design pressure
is reached. Thereafter, the test pressure shall be increased
in steps of approximately one-tenth or less of the anticipated
design pressure until the pressure required by the
test procedure is reached. The pressure shall be held
stationary at the end of each increment for a sufficient
time to allow the observations required by the test procedure
to be made and shall be released to zero to permit
determination of any permanent strain or displacement
after any pressure increment that indicates an increase in
strain or displacement over the previous equal pressure
increment.
HG-501.5 Critical Areas. As a check that the
measurements are being taken on the most critical
areas, the Inspector may require a lime wash or other
brittle coating to be applied on all areas of probable
high stress concentrations in the test procedures given
in HG-502.1 and HG-502.2. The surfaces shall be suitably
clean before the coating is applied in order to obtain satisfactory
adhesion. The technique shall be suited to the
coating material.
NOTE: Strains should be measured as they apply to membrane
stresses. In regard to bending stresses it is recognized that high
localized and secondary stresses may exist in pressure parts
designed and fabricated in accordance with these rules.
Insofar as practical, design rules for details have been
written to hold such stresses at a safe level consistent with
experience.
HG-501.6 Yield Strength and Tensile Strength.
For proof tests based on yielding, HG-502.1 and
HG-502.2, the yield strength (or yield point for those materials
that exhibit that type of yield behavior indicated by a
“sharp-kneed” portion of the stress–strain diagram) of the
material in the part tested, shall be determined in accordance
with the method prescribed in the applicable material
specification and as described in ASTM E8, Tension
Testing of Metallic Materials. For proof tests based on
bursting, HG-502.3, the tensile strength instead of the
yield strength of the material in the part tested shall
be similarly determined.
ASME BPVC.IV-2025
37

electrode, stranded: a composite filler metal electrode
consisting of stranded wires which may mechanically
enclose materials to improve properties, stabilize the
arc, or provide shielding.
electrode, tungsten: a nonfiller metal electrode used in arc
welding, arc cutting, and plasma spraying, made principally
of tungsten.
electrofusion (EF): fusing accomplished by heating polyethylene
materials above their melting points using electric
elements within a confined space, producing
temperatures and pressures necessary to achieve coalescence
of the molten polyethylene materials during the
cooling phase. Some of the more common terms relating
to EF are defined in ASTM F1290 and ASTM F412.
electrofusion manufacturer: the manufacturer of electrofusion
fittings.
face feed: the application of filler metal to the face side of a
joint.
filler metal: the metal or alloy to be added in making a
welded, brazed, or soldered joint.
filler metal, brazing: the metal or alloy used as a filler metal
in brazing, which has a liquidus above 840°F (450 °C) and
below the solidus of the base metal.
filler metal, powder: filler metal in particle form.
filler metal, supplemental: in electroslag welding or in a
welding process in which there is an arc between one
or more consumable electrodes and the workpiece, a
powder, solid, or composite material that is introduced
into the weld other than the consumable electrode(s).
fillet weld: a weld of approximately triangular cross
section joining two surfaces approximately at right
angles to each other in a lap joint, tee joint, or corner joint.
flaw: an undesirable discontinuity. See also defect.
flux (welding or brazing): a material used to dissolve,
prevent, or facilitate the removal of oxides or other undesirable
surface substances. It may act to stabilize the arc,
shield the molten pool, and may or may not evolve
shielding gas by decomposition.
flux cover: metal bath dip brazing and dip soldering. A layer
of molten flux over the molten filler metal bath.
flux, active (SAW): a flux from which the amount of
elements deposited in the weld metal is dependent
upon the welding parameters, primarily arc voltage.
flux, alloy (SAW): a flux which provides alloying elements
in the weld metal deposit.
flux, neutral (SAW): a flux which will not cause a significant
change in the weld metal composition when there is a
large change in the arc voltage.
forehand welding: a welding technique in which the
welding torch or gun is directed toward the progress
of welding.
frequency: the completed number of cycles which the oscillating
head makes in 1 min or other specified time increment.
frictional resistance in the butt-fusing machine: forceopposing
movement due to friction in the mechanism
of the fusing machine.
fuel gas: a gas such as acetylene, natural gas, hydrogen,
propane, stabilized methylacetylene propadiene, and
other fuels normally used with oxygen in one of the
oxyfuel processes and for heating.
fused spray deposit (thermal spraying): a self-fluxing
thermal spray deposit which is subsequently heated to
coalescence within itself and with the substrate.
fusing (plastic fusing): the process of producing a fusion
joint. Butt, manual butt, electrofusion, and sidewall are the
fusing processes addressed in this Code.
fusing gauge pressure: the hydraulic gauge pressure to be
observed by the fusing operator when butt fusing or sidewall
fusing polyethylene (PE) piping. This is the sum of the
theoretical fusing pressure plus the drag pressure.
fusing operator: person trained and qualified to carry out
fusing of polyethylene (PE) pipes and/or fittings using a
butt-fusing or sidewall-fusing procedure or electrofusion
procedure with applicable equipment.
fusing procedure specification: a document providing in
detail the required variables for the fusing process to
ensure repeatability in the fusing procedure. This
generic term includes fusing procedure specifications
qualified by testing (FPS), as well as standard fusing procedure
specifications (SFPS) or manufacturer qualified electrofusion
procedure specifications (MEFPS).
fusion (fusion welding): the melting together of filler metal
and base metal, or of base metal only, to produce a weld.
fusion (plastic fusing): the portion of the fusing process
involving the coalescence of two plastic members by
the combination of controlled heating and the application
of pressure approximately normal to the interface
between them; the joint produced by plastic fusing.
fusion face: a surface of the base metal that will be melted
during welding.
fusion interfacial pressure: the interfacial pressure applied
during the fusion phase of the fusing process.
fusion line: a non-standard term for weld interface.
gas backing: see backing gas.
globular transfer (arc welding): a type of metal transfer in
which molten filler metal is transferred across the arc in
large droplets.
groove weld: a weld made in a groove formed within a
single member or in the groove between two members
to be joined. The standard types of groove weld are as
follows:

crack: a fracture-type discontinuity characterized by a
sharp tip and high ratio of length and width to
opening displacement.
creep strength enhanced ferritic alloys (CSEF’s): a family of
ferritic steels whose creep temperature strength is
enhanced by the creation of a precise condition of microstructure,
specifically martensite or bainite, which is stabilized
during tempering by controlled precipitation of
temper-resistant carbides, carbo-nitrides, or other
stable and/or meta-stable phases.
data acquisition record: a detailed, permanent record of
variables applicable to the fusing process, such as buttfusion
pressure, electrofusion voltage, and cycle cooldown
times, along with the measured heater surface
temperature, employee information, butt-fusing or electrofusion
machine information, pipe information, date,
and time for each joint made.
defect: a discontinuity or discontinuities that by nature or
accumulated effect (for example, total crack length)
render a part or product unable to meet minimum applicable
acceptance standards or specifications. This term
designates rejectability. See also discontinuity and flaw.
direct current electrode negative (DCEN): the arrangement
of direct current arc welding leads in which the electrode
is the negative pole and the workpiece is the positive pole
of the welding arc.
direct current electrode positive (DCEP): the arrangement
of direct current arc welding leads in which the electrode
is the positive pole and the workpiece is the negative pole
of the welding arc.
discontinuity: an interruption of the typical structure of a
material, such as a lack of homogeneity in its mechanical,
metallurgical, or physical characteristics. A discontinuity
is not necessarily a defect. See also defect and flaw.
double-welded joint: a joint that is welded from both sides.
double-welded lap joint: a lap joint in which the overlapped
edges of the members to be joined are welded along the
edges of both members.
drag pressure: the pressure required to overcome the drag
resistance and frictional resistance in the butt-fusing
machine and keep the carriage moving at its slowest
speed.
drag resistance: force-opposing movement of the movable
clamp of the butt-fusing machine due to the weight of the
pipe.
dwell: the time during which the energy source pauses at
any point in each oscillation.
electrode, arc welding: a component of the welding circuit
through which current is conducted.
electrode, bare: a filler metal electrode that has been
produced as a wire, strip, or bar with no coating or
covering other than that incidental to its manufacture
or provided for purposes of preservation, feeding, or electrical
contact.
electrode, carbon: a nonfiller material electrode used in arc
welding and cutting, consisting of a carbon or graphite rod,
which may be coated with copper or other materials.
electrode, composite: a generic term of multicomponent
filler metal electrodes in various physical forms, such
as stranded wires, tubes, and covered electrodes.
electrode, covered: a composite filler metal electrode
consisting of a core of a bare electrode or metal-cored
electrode to which a covering sufficient to provide a
slag layer on the weld metal has been applied. The
covering may contain materials providing such functions
as shielding from the atmosphere, deoxidation, and arc
stabilization, and can serve as a source of metallic additions
to the weld.
electrode, electroslag welding: a filler metal component of
the welding circuit through which current is conducted
between the electrode guiding member and the molten
slag.
NOTE: Bare electrodes and composite electrodes as defined
under arc welding electrode are used for electroslag welding.
A consumable guide may also be used as part of the electroslag
welding electrode system.
electrode, emissive: a filler metal electrode consisting of a
core of a bare electrode or a composite electrode to which
a very light coating has been applied to produce a stable
arc.
electrode, flux-cored: a composite filler metal electrode
consisting of a metal tube or other hollow configuration
containing ingredients to provide such functions as
shielding atmosphere, deoxidation, arc stabilization,
and slag formation. Alloying materials may be included
in the core. External shielding may or may not be used.
electrode, lightly coated: a filler metal electrode consisting
of a metal wire with a light coating applied subsequent to
the drawing operation, primarily for stabilizing the arc.
electrode, metal: a filler or nonfiller metal electrode used in
arc welding and cutting that consists of a metal wire or rod
that has been manufactured by any method and that is
either bare or covered.
electrode, metal-cored: a composite filler metal electrode
consisting of a metal tube or other hollow configuration
containing alloying ingredients. Minor amounts of ingredients
providing such functions as arc stabilization and
fluxing of oxides may be included. External shielding
gas may or may not be used.
electrode, resistance welding: the part of a resistance
welding machine through which the welding current
and, in most cases, force are applied directly to the workpiece.
The electrode may be in the form of a rotating wheel,
rotating roll, bar, cylinder, plate, clamp, chuck, or modification
thereof.
ASME BPVC.IX-2025

ASME Sec IX 2025 GENERAL REQUIREMENTS
ð25Þ QG-100 SCOPE
(a) This Section contains requirements for the qualification
of welders, welding operators, brazers, brazing
operators, plastic fusing operators, and the materialjoining
processes they use during welding, brazing, and
fusing operations for the construction of components
under the rules of the ASME Boiler and Pressure
Vessel Code, the ASME B31 Codes for Pressure Piping,
and other Codes, standards, and specifications that reference
this Section. This Section is divided into four parts.
(1) Part QG contains general requirements for all
material-joining processes.
(2) Part QW contains requirements for welding.
(3) Part QB contains requirements for brazing.
(4) Part QF contains requirements for plastic fusing.
(b) Whenever the referencing Code, standard, or specification
imposes qualification requirements different
than those given in this Section, the requirements of
the referencing Code, standard, or specification shall
take precedence over the requirements of this Section.
(c) Some of the more common terms relating to material-
joining processes are defined in QG-109. Whenever
the word “pipe” is used, “tube” shall also be applicable.
(d) New editions to Section IX may be used beginning
with the date of issuance and become mandatory 6 months
after the date of issuance.
(e) Code Cases are permissible and may be used, beginning
with the date of approval by ASME. Only Code Cases
that are specifically identified as being applicable to this
Section may be used. At the time a Code Case is applied,
only the latest revision may be used. Code Cases that have
been incorporated into this Section or have been annulled
shall not be used for new qualifications, unless permitted
by the referencing Code. Qualifications using the provisions
of a Code Case remain valid after the Code Case
is annulled. The Code Case number shall be listed on
the qualification record(s).
(f) Throughout this Section, references are made to
various non-ASME documents. Unless a specific date is
referenced, the latest edition of the reference document
in effect at the time of performance or procedure qualification
is to be used.
(g) This Section does not fully address tolerances.
When dimensions, sizes, or other parameters are not
specified as maximums, minimums, or with tolerances,
the values of these parameters are considered nominal,
and allowable tolerances or local variances may be considered
acceptable when using standard practices based on
engineering judgment.
QG-101 PROCEDURE SPECIFICATION
A procedure specification is a written document
providing direction to the person applying the material-
joining process. Details for the preparation and qualification
of procedure specifications for welding (WPS),
brazing (BPS), and fusing (FPS) are given in the respective
Parts addressing those processes. Procedure specifications
used by an organization (see QG-109.2) having
responsibility for operational control of materialjoining
processes shall have been qualified by that organization,
or shall be a standard procedure specification
acceptable under the rules of the applicable Part for
the joining process to be used. Procedure specifications
shall be available for reference and review at the fabrication
site.
Procedure specifications address the conditions
(including ranges, if any) under which the materialjoining
process must be performed. These conditions
are referred to in this Section as “variables.” A procedure
specification shall address, as a minimum, the specific
essential and nonessential variables that are applicable
to the material-joining process to be used in production.
When the referencing code, standard, or specification
requires toughness qualification of the material-joining
procedure, the applicable supplementary essential variables
shall also be addressed in the procedure specification.
QG-102 PROCEDURE QUALIFICATION RECORD
The purpose of qualifying the procedure specification is
to demonstrate that the joining process proposed for
construction is capable of producing joints having the
required mechanical properties for the intended application.
Qualification of the procedure specification demonstrates
the mechanical properties of the joint made using a
joining process, and not the skill of the person using the
joining process.
The procedure qualification record (PQR) documents
what occurred during the production of a procedure qualification
test coupon and the results of testing that coupon.
ASME BPVC.IX-2025
1QG-106.1 Procedure Qualifications. Each organization
is responsible for conducting the tests required by
this Section to qualify the procedures that are used in
the construction of components under the rules of the
Codes, standards, and specifications that reference this
Section.
(a) The personnel who produce test joints for procedure
qualification shall be under the full supervision and
control of the qualifying organization during the production
of these test joints.
(b) Production of qualification test joints under the
supervision and control of another organization is not
permitted, except as permitted in QG-106.4. However,
it is permitted to subcontract any or all of the work necessary
for preparing the materials to be joined, the subsequent
work for preparing test specimens from the
completed test joint, and the performance of nondestructive
examination and mechanical tests, provided the organization
accepts full responsibility for any such work.
(c) If the effective operational control of procedure
qualifications for two or more companies of different
names exists under the same corporate ownership, the
companies involved shall describe in their quality
programs the operational control of procedure qualifications.
In this case, separate procedure qualifications are
not required, provided all other requirements of this
Section are met.
QG-106.2 Performance Qualifications. Each organization
is responsible for the supervision and control of material
joining performed by persons for whom they have
operational responsibility and control. The organization
shall conduct the tests required by this Section to qualify
the performance of those persons with each joining
process they will use for the construction of components
under the rules of the Codes, standards, and specifications
that reference this Section. This requirement ensures that
the qualifying organization has determined that the personnel
using its procedures are capable of achieving the
minimum requirements specified for an acceptable joint.
This responsibility cannot be delegated to another organization.
(a) The personnel who produce test joints for performance
qualification shall be tested under the full supervision
and control of the qualifying organization.
(b) The performance qualification test shall be
performed following either a qualified procedure specification
or a standard procedure specification acceptable
under the rules of the applicable Part for the joining
process. The Part addressing any specific joining
process may exempt a portion of the procedure specification
from being followed during production of the
performance qualification test coupon.
(c) Production of test joints under the supervision and
control of another organization is not permitted. It is
permitted to subcontract any or all of the work necessary
for preparing the materials to be joined in the test joint,
and the subsequent work for preparing test specimens
from the completed test joint, and the performance of
nondestructive examination and mechanical tests,
provided the organization accepts full responsibility
for any such work.
(d) The performance qualification test may be terminated
at any stage, whenever it becomes apparent to the
supervisor conducting the tests that the person being
tested does not have the required skill to produce satisfactory
results.
(e) When a procedure qualification test coupon has
been tested and found acceptable, the person who
prepared the test coupon is also qualified for the
joining process used, within the ranges specified for
performance qualification for the applicable process(es).
(f) Persons who are successfully qualified shall be
assigned an identifying number, letter, or symbol by
the organization, which shall be used to identify their
work.
(g) If effective operational control of performance
qualifications for two or more companies of different
names exists under the same corporate ownership, the
companies involved shall describe in their quality
programs the operational control of performance qualifications.
In this case, requalification of persons working
within the companies of such an organization are not
required, provided all other requirements of this
Section are met.
QG-106.3 Simultaneous Performance Qualifications.
Organizations may participate in an association to collectively
qualify the performance of one or more persons for
material-joining processes simultaneously and may share
performance qualification information with other participating
organizations within the association. When simultaneous
performance qualifications are conducted, each
participating organization shall be represented by an
employee with designated responsibility for performance
qualifications.
(a) The essential variables of the procedure specifications
to be followed during simultaneous performance
qualifications shall be compared by the participating organizations,
and shall be identical, except as otherwise
provided in the Part addressing the specific joining
method. The qualified thickness ranges need not be identical
but shall include the test coupon thickness.
(b) Alternatively, the participating organizations shall
agree to follow a single procedure specification that has
been reviewed and accepted by each participating organization.
Each participating organization shall have a
supporting PQR or shall have accepted responsibility
for using a standard procedure specification having a
range of variables consistent with those to be followed
during the performance qualification test, in accordance
with the applicable Part for the joining method.
(c) Each participating organization’s representative
shall

brazing, block (BB): a brazing process that uses heat from
heated blocks applied to the joint. This is an obsolete or
seldom used process.
brazing, dip (DB): a brazing process in which the heat
required is furnished by a molten chemical or metal
bath. When a molten chemical bath is used, the bath
may act as a flux; when a molten metal bath is used,
the bath provides the filler metal.
brazing, furnace (FB): a brazing process in which the workpieces
are placed in a furnace and heated to the brazing
temperature.
brazing, induction (IB): a brazing process that uses heat
from the resistance of the workpieces to induced electric
current.
brazing, machine: brazing with equipment which
performs the brazing operation under the constant observation
and control of a brazing operator. The equipment
may or may not perform the loading and unloading of the
work.
brazing, manual: a brazing operation performed and
controlled completely by hand. See also automatic
brazing and machine brazing.
brazing, resistance (RB): a brazing process that uses heat
from the resistance to electric current flow in a circuit of
which the workpieces are a part.
brazing, semiautomatic: brazing with equipment which
controls only the brazing filler metal feed. The advance
of the brazing is manually controlled.
brazing, torch (TB): a brazing process that uses heat from a
fuel gas flame.
build-up of base metal (restoration of base metal thickness):
this is the application of a weld material to a base metal so
as to restore the design thickness and/or structural integrity.
This build-up may be with a chemistry different from
the base metal chemistry which has been qualified via a
standard butt-welded test coupon. Also, may be called
base metal repair or buildup.
butt joint: a joint between two members aligned approximately
in the same plane.
butt-fusing cycle: pressure–time diagram for a defined
fusing temperature, representing the entire fusing operation.
butt-fusing pressure: the sum of the theoretical butt-fusing
pressure plus the drag pressure. This is verified by the
gauge pressure used by the fusing operator on the
butt-fusing machine to join the pipe ends or by applied
torque when torque verification is required by the
fusing procedure specification (FPS).
butt fusion (BF): fusing accomplished by heating the ends
of polyethylene pipes above their melting point using a
contact heater, then removing the heater and applying
pressure necessary to achieve coalescence of the
molten polyethylene materials during the cooling
phase. Some of the more common terms relating to BF
are defined in ASTM F412.
buttering: the addition of material, by welding, on one or
both faces of a joint, prior to the preparation of the joint for
final welding, for the purpose of providing a suitable transition
weld deposit for the subsequent completion of the
joint.
clad or cladding: weld metal overlay or bonded corrosionresistant
material added to a metal surface.
clad brazing sheet: a metal sheet on which one or both
sides are clad with brazing filler metal.
coalescence: the growing together or growth into one body
of the materials being joined.
complete fusion: fusion which has occurred over the entire
base material surfaces intended for welding, and between
all layers and beads.
consumable insert: filler metal that is placed at the joint
root before welding, and is intended to be completely
fused into the root to become part of the weld.
contact tube: a device which transfers current to a continuous
electrode.
control method (FSW): the manner of monitoring and
controlling the position of the rotating tool with
respect to the weld joint during the friction stir
welding process.
control method, force (FSW): a control method that uses a
force set point, such as plunge force or travel force, to
control the tool position. Under the force control
method, the plunge depth or travel speed can vary,
within a specified range, during welding.
control method, position (FSW): a control method that uses
a set plunge position relative to the plate surface to control
the tool position. Under the position control method, the
plunge force can vary, within a specified range, during
welding.
control method, travel (FSW): a control method that uses a
set travel speed to control the tool position. Under the
travel control method, the travel force can vary, within
a specified range, during welding.
control specimen: a section from the base material tested
to determine its tensile strength for the purpose of
comparing to the tensile strength of the fused joint.
cool time at butt-fusing pressure: the minimum time that
the butt-fusing pressure shall be maintained between the
pipe faces while the pipe joint cools. This is a function of
the wall thickness.
corner joint: a joint between two members located
approximately at right angles to each other in the form
of an L.
coupon: see test coupon.