Pemex Refinacion

Plantas Desulfuradoras (ULSG) Salamanca USLG

de Gasolinas Cataliticas Specification 20072-SW-233
Número de Contrato : PR-SO-A-013/06P Equipment Welding

ISSUED BY: MECHANICAL ENGINEERING DEPT.

APPROVED: KA

DATE: Nov 6, 2007 REV.: 1

This document is the property of CDTECH, including all patented and patentable features and/or
confidential information, and its use is conditioned upon the user's agreement not to reproduce the
document, in whole or in part, nor the material described thereon, nor to use the document for any
purpose other than as specifically permitted in writing by CDTECH.

1 11/06/07 Revised per Client comment 4,26 VH KA

0 2/23/07 For BEP VH KA
A 01/31/07 Preliminary Issue - VH KA

Rev. Revision Pages Written Approved

Date
No. Description Revised By By

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Pemex Refinacion
Plantas Desulfuradoras (ULSG) Salamanca USLG
de Gasolinas Cataliticas Specification 20072-SW-233
Número de Contrato : PR-SO-A-013/06P Equipment Welding

Table of Contents

1.0 SCOPE 4

2.0 DEFINITIONS 4

3.0 SUPPLIER RESPONSIBILITY 4

4.0 REGULATIONS 5
4.1 Codes 5
4.2 Standards 6
4.3 Reference ABB Specifications 6

5.0 FABRICATION 6
5.1 Welding Processes and Restrictions 6
5.2 Filler Metals and Flux 8
5.3 General Welding Requirements 12
5.4 Dissimilar Metal Welds 14
5.5 Clad Plate and Overlay Welding 15
5.6 Preheat And Interpass Temperature 16
5.7 Post Weld Heat Treatment 18
5.8 Repair 19

6.0 INSPECTION 21
6.1 Weld Quality and Weld Inspection 21
6.2 General Nondestructive Examination (NDE) 22
6.3 Visual Examination 23
6.4 Magnetic Particle Examination (MT) 23
6.5 Liquid Penetrant Examination (PT) 23
6.6 Radiographic Testing (RT) 23
6.7 Ultrasonic Examination (UT) 24
6.8 NDE of Weld Overlay and Clad Restoration 24
6.9 Hardness Testing 24
6.10 CVN Impact Testing 26

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Plantas Desulfuradoras (ULSG) Salamanca USLG
de Gasolinas Cataliticas Specification 20072-SW-233
Número de Contrato : PR-SO-A-013/06P Equipment Welding

7.0 SUPPLIER DOCUMENTATION 26

7.1 Weld Maps 26
7.2 Un-Listed Base and Filler Metal for Welding Qualification 27
7.3 Welding Procedure Specification (WPS) 27
7.4 Procedure Qualification Record (PQR) 27
7.5 Repair Welding Plan 28
7.6 Overlay and Clad Restoration Plan 28
7.7 Post Weld Heat Treatment (PWHT) 29
7.8 NDE Procedures: 29

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Plantas Desulfuradoras (ULSG) Salamanca USLG
de Gasolinas Cataliticas Specification 20072-SW-233
Número de Contrato : PR-SO-A-013/06P Equipment Welding

1.0 SCOPE
This specification establishes the minimum requirements for welding, post weld heat treatment, and NDE
of pressure containing equipment including, but not limited to, pressure vessels, heat exchangers, coolers,
towers, columns, tanks (including API tanks), steam generators, fired heater coils, fabricated casings for
pumps, compressors, turbines, and the attachments to the above equipment. The requirements for the
welding, heat treatment, and NDE of ASME B31.1 and B31.3 piping are contained in ABB SW-231. The
requirements for non-pressure containing equipment, repairs to non-pressure castings, and structural
steelwork are outside the scope of this specification.

2.0 DEFINITIONS
Purchaser The Purchaser is defined as PEMEX REFINACION.
Supplier The Supplier is defined as the party with whom the purchase order/subcontract is placed,
as shown on the face of the Purchase Order/subcontract. The Supplier shall ensure that
any and all of their Subcontractors comply with the Purchase Order or subcontract
requirements in full. (Supplier is synonymous with Vendor, Seller)
Owner The Owner is defined as the ultimate user of the equipment. (Owner is synonymous with
Client)
Manufacturer The manufacturer of welding consumable materials.
WPS Welding Procedure Specification.
PQR Procedure Qualification Record.
HAZ Heat Affected Zone.
PWHT Post Weld Heat Treatment
DMW Dissimilar Metal Weld.
NDE Non Destructive Examination (NDE is synonymous with NDT and NDI)
T Base Metal Thickness
t Weld Metal Thickness, less reinforcement

3.0 SUPPLIER RESPONSIBILITY

Welding, inspection, and other criteria covered by this specification shall meet or exceed the requirements
of any Codes referenced herein or in the Purchase Order documentation. Where more stringent than Code
requirements, Purchaser requirements shall supercede Code minimum requirements.In case of conflict
between the requirements of this Specification and other applicable ABB Specifications, Codes,
Standards, data sheets, drawings, Purchase Order, etc., the following order of precedence shall govern:
1) Purchase Order package Including Data Sheets and Specific Equipment Specification
2) Attached Project Specifications (eg.: this Specification)

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Plantas Desulfuradoras (ULSG) Salamanca USLG
de Gasolinas Cataliticas Specification 20072-SW-233
Número de Contrato : PR-SO-A-013/06P Equipment Welding

3) Other referenced Codes and Specifications

If a conflict cannot be resolved, the Purchaser shall be consulted and a ruling in writing shall be obtained
by the Supplier before any associated work is continued. Supplier shall not make assumptions to replace
information not furnished by Purchaser. Supplier is required to obtain necessary information from
Purchaser. Any and all claims arising from lack of knowledge or required information shall be rejected by
Purchaser. Supplier shall itemize, list, and fully describe all deviations from this Specification and the
related Standards with the quote for the equipment.

4.0 REGULATIONS
The following documents, including applicable Addenda, constitute a part of this Specification as
described herein. The referenced edition of these documents shall be that which is in effect at the issue
date of this Specification unless otherwise specified in Purchase Order documents.

4.1 Codes
Supplier shall comply with all applicable Federal, State, and local Codes including :
ASTM American Society for Testing and Materials
E-10 Standard Test Method for Brinell Hardness Test of Metallic Materials
E-23 Standard Test Methods for Notched Bar Impact Testing of Metallic
Materials
ASME American Society of Mechanical Engineers
Boiler and Pressure Vessel Code
Section II Materials Specification, Part C
Section V Nondestructive Examination
Section VIII Pressure Vessels, Division 1
Pressure Vessels, Division 2
Section IX Welding and Brazing Qualifications
ASNT American Society for Nondestructive Testing
SNT-TC-1A Recommended Practice

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Plantas Desulfuradoras (ULSG) Salamanca USLG
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Número de Contrato : PR-SO-A-013/06P Equipment Welding

4.1.1 Nondestructive Examination (NDE)

Where required, NDE shall conform with the following Codes, unless otherwise stated in
the product/commodity Specification.

Method Code
Magnetic Particle Testing (MT) ASME V, Article 7 and
ASME VIII, Appendix 6
Liquid Penetrant Testing (PT) ASME V, Article 6 and
ASME VIII, Appendix 8
Radiographic Testing (RT)
Complete RT ASME V, Article 2 and
ASME VIII, UW 51

Random (Spot) RT ASME V, Article 2 and

ASME VIII, UW 52
Ultrasonic Testing (UT) ASME V, Article 5 and
ASME VIII, Appendix 12
Visual Testing (VT) ASME V, Article 9

4.2 Standards
Supplier shall comply with the following Standards, when applicable :
API 620 Design and Construction of Large, Welded, Low Pressure Storage Tanks,
API 650 Welded Steel Tanks for Oil Storage.

4.3 Reference ABB Specifications

Supplier shall comply with the following Specifications, when applicable :
D-201 Pressure Vessels
EA-201 Shell and Tube Heat Exchange Equipment

5.0 FABRICATION

5.1 Welding Processes and Restrictions

The following welding processes are permitted, subject to the conditions given below for each
process :
5.1.1 Shielded Metal-Arc Welding (SMAW)
• Except for carbon steels, the SMAW process shall not be used for welding the root
pass of single side welded groove welds.

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Plantas Desulfuradoras (ULSG) Salamanca USLG
de Gasolinas Cataliticas Specification 20072-SW-233
Número de Contrato : PR-SO-A-013/06P Equipment Welding

• Root pass welds made using cellulosic electrodes shall have the hot pass performed
without delay after the root pass weld is completed and cleaned.
• The maximum bead width shall be the smaller of three times the electrode core
diameter or 5/8 in. (16 mm).
5.1.2 Gas Tungsten-Arc Welding (GTAW)
• The maximum bead width shall be 3/8 in. (10 mm).
• The GTAW power source shall be operated using a high frequency arc-starting circuit.
• Autogenous welding (without filler metal) is prohibited.
5.1.3 Submerged Arc Welding (SAW)
• Flux used shall be "neutral" and shall not contribute alloying elements to the weld.
• The maximum bead width shall be seven times the electrode diameter.
• For all base materials, except carbon steel, when CVN impact testing is required, the
production welding consumables shall be essential variables for the WPS. In this
case, production SAW consumables are restricted to the same Manufacturer and
Brand as were used for the supporting PQR with supporting CVN data.
• Material for run-on and run-off pads shall be known (or chemically verified) and shall
be the same P-Number as the base metal to be welded.
• Use of SAW flux manufactured from crushed SAW slag (“re-crushed”) is prohibited.
• Production single pass butt welds for pressure boundary joints shall be CVN tested at
MDMT or shall be given a grain refining (austenitization) heat treatment.
5.1.4 Gas-Shielded Flux Core Arc Welding (FCAW)
The gas-shielded FCAW may be used for P-1 through P-8 Group 1 materials, subject to
following conditions :
• Welds for pressure containing equipment shall be 100% radiographed or 100%
ultrasonically examined. Welds for API storage tanks are exempt from this
requirement.
• Only electrodes identified by the Manufacturer as multi-pass shall be used.
• The maximum bead width shall be 3/4 in. (19 mm). For weave beads, the range of
transverse motion for the electrode shall be maximum 5x the electrode diameter.
• A shielding gas is employed, and the transfer mode is not short-circuiting.
• The FCAW process shall not be used for the root pass of single side welded joints.
• Production welding positions shall be in strict accordance with the FCAW
classification designation per ASME Sect. II, Part C.
• For all base materials except carbon steel, weld overlay, and weld back cladding, the
production FCA welding consumables are restricted to the same Manufacturer and
Brand as were used for the supporting PQR when CVN impact testing is required.

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5.1.5 Gas Metal Arc Welding GMAW (spray, pulse spray transfer modes)
The GMAW process with pulse-spray or spray transfer may be used for P-1 through P-8
Group 1 materials, subject to the following conditions :
• Welds for pressure containing equipment shall be 100% radiographed or 100%
ultrasonically examined. Welds for API storage tanks are exempt from this
requirement.
• The maximum bead width shall be 3/4 in. (19 mm).
5.1.5.1 Pulsed GMAW
• The computer controlled pulsed GMAW process shall use machine settings
for all applied electrical parameters and travel speed that are essentially the
same as those used for PQR. The welding power source and computer control
module shall be considered essential variables for the WPS and shall be the
same as used for PQR.
5.1.6 GMAW – (short circuit or globular transfer mode)
GMAW-S, short circuit transfer, and GMAW-G with globular transfer may be used for
P-1, Group 1, and P-8, Group 1 materials under the following conditions :
• For the root pass of single-sided joint in any thickness, provided the complete weld is
100% radiographed or 100% ultrasonically examined.
• For the root pass of double-sided joint in any thickness, provided the root pass is
100% back-gouged to remove all root weld metal.
• For the fill passes provided the base material thickness of any member does not
exceed 3/8 in. (9.5 mm).
5.1.7 Plasma Arc Welding (PAW)
Plasma-arc welding (PAW) may be used for :
• Hard surfacing, overlaying and fully automatic butt-welding.
• For welding Titanium, Zirconium, Hastelloy, Monel, Duplex stainless steel or other
corrosion-resistant alloys.
5.1.8 Welding processes (e.g.: ESW, EGW, etc.) other than those listed above require specific
written approval from the Purchaser. For ESW and EGW, any single pass butt welds of
pressure boundary joints shall be CVN tested at MDMT or shall be given a grain refining
(austenitization) heat treatment.
5.2 Filler Metals and Flux
5.2.1 General
5.2.1.1 Electrode rods, electrode wires, and fluxes shall be kept clean, dry, and properly
stored in strict accordance with the Manufacturer’s recommendation. For coated
electrodes, cored electrodes, and flux, drying temperatures and times shall comply

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Plantas Desulfuradoras (ULSG) Salamanca USLG
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Número de Contrato : PR-SO-A-013/06P Equipment Welding

strictly with the Manufacturer’s instructions. Use of damp, greasy, oxidized,

rusted, or otherwise contaminated electrodes, filler wire, or flux is prohibited.
5.2.1.2 Filler metal shall be similar with respect to elemental composition, corrosion
resistance, and mechanical properties to the base metal being welded.
5.2.1.3 When joining two different ferritic steels, or when joining ferritic to martensitic
steels, the filler metal shall match the nominal chemistry of either base metal, and
the weld metal mechanical properties shall conform to base metal minimum
requirements. For attaching non-pressure parts to pressure parts, the filler metal
chemistry shall match the nominal chemistry of the pressure part.
5.2.1.4 Filler metals shall conform to the ASME Boiler and Pressure Vessel Code,
Section II, Part C. Qualification of WPS is required when the flux composition or
filler metal chemistry cited in PQR is changed from one AWS classification to an
unlisted classification or to a general [suffix “G”] classification.
5.2.1.5 Alternatively, and prior to use, the Supplier shall submit to the Purchaser a written
request for approval to use filler metals manufactured to other
Standards/Specifications or to use filler metals with an AWS/ASME “G”
classification. Supplier shall submit published material specifications and
certified material test reports with any request for filler metal approval.
5.2.1.6 Welding consumables recommended per AWS/ASME for non-PWHT
applications shall not be used for applications requiring PWHT.
5.2.1.7 Welding consumables recommended per AWS/ASME for single pass welding
shall not be used for multiple pass welding.
5.2.2 SMAW (carbon and low alloy steels)
With reference to ASME BPVC Section IX QW-432, type F-1 and F-2 electrodes shall be
used for non-pressure fillet welds only.
Type F-3 electrodes may be used for the root pass of groove welds in carbon steels
provided the weld is not required to be impact tested, and provided welds using cellulosic
electrodes shall have the hot pass performed without delay after the root pass weld is
completed and cleaned.
For pressure welds, type F-4 “low hydrogen” electrodes shall be used for weld-out and
fillet welds in carbon and alloy steel materials.
For welding of carbon steels (P-1) use only E-7018-1 electrodes when material service has
impact requirements. Use of filler metal equivalents with improved toughness requires
Purchaser notification and approval.
5.2.3 GTAW
Use of ER 70-SG (SFA 5.18) filler metal is prohibited.
5.2.4 GMAW
Use of ER 70-SG (SFA 5.18) filler metal is prohibited.

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5.2.5 FCAW
Use of EXX-T3 or EXXT-G wires (SFA 5.20) is prohibited.
FCAW filler metal for welding of pressure containing equipment made with ferritic
materials, other than P-1 materials, shall have a Manufacturer’s certified diffusible
hydrogen limit of H8 (per AWS A5.20).
When CVN or hardness testing is required by Code or Purchaser Specification, for
pressure boundary welds made with gas shielded FCAW, the filler electrode
Manufacturer’s brand name consumable used for qualification shall be an essential
variable for the WPS.
5.2.6 SAW
Flux used shall be "neutral" and shall not contribute alloying elements to the weld.
Use of SAW flux manufactured from crushed SAW slag (“re-crushed”) is prohibited.
When CVN or hardness testing is required by Code or Purchaser Specification, for
pressure boundary welds made with SAW, the flux and filler electrode Manufacturer’s
brand name consumables used for qualification shall be an essential variable for the WPS.
5.2.7 Stainless Steel
Type 308L filler metal shall be used for welding Type 304L stainless steel.
Type 310 filler metal shall be used only for welding Type 310 to Type 310.
Type 347 filler metal shall be used for welding Type 321 stainless steel.
5.2.7.1 Ferrite Control
Austenitic (300 series) stainless steel welding consumables (except type 310),
including overlay welding and DMW consumables, shall be purchased with
controlled ferrite. Delta ferrite content of weld metal is restricted to minimize
problems of hot cracking during welding and/or sigma phase precipitation during
service. Per the Purchase Order, and as needed to evaluate ferrite content,
Supplier shall submit stainless steel filler metal manufacturer’s CMTR with each
associated PQR for each filler metal heat/lot to be used in production.
The Ferrite content shall be calculated using the diagrams from ASME Sect. II,
Part C, SFA 5.9. Calculation based on the WRC Diagram shall have ferrite
number (FN) in the range of 3-to-11 inclusive, and calculation based on the
DeLong diagram shall have ferrite percent in the range of 2%-to-10% inclusive.
The actual nitrogen content, or an assumed nitrogen content shall be included in
the calculations. Assumed nitrogen contents shall be 0.12% for FCAW filler
metals, 0.08% for GMAW filler metals, and 0.06% for all other filler metals.
With Purchaser approval, these requirements may be relaxed as needed to comply
with impact toughness requirements for very low temperature service applications.
Ferrite content based on magnetic measurement instruments provided the
instruments are calibrated in accordance with AWS A4.2 and provided a ferrite
measurement procedure is provided for review in advance.

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5.2.8 Dissimilar Metal Welding (DMW)

Each application of DMW between ferritic and austenitic materials shall require Purchaser
approval.
For joining austenitic stainless steel or nickel-base alloys to ferritic steels, use filler
material selected per the following table:

Design Temperature Filler Metal*

≤600°F (≤315°C) Type E309L, ER309L

>600°F (>315°C) and Inconel 82 (SFA 5.14 ERNiCr-3) or
≤1000°F (≤537°C) Inconel 182 (SFA 5.11 ENiCrFe-3)
>1000°F (>537°C) Inconel 82 (SFA 5.14 ERNiCr-3) or
Inconel 617 (SFA 5.14 ERNiCrCoMo-1) or
Inco-Weld “A” (SFA 5.11 ENiCrFe-2) or
Inconel 117 (SFA 5.11 ENiCrCoMo-1)

* Filler metal acceptable for the higher temperature application may be substituted for
filler metal designated for the lower temperature application
5.2.9 Weld Overlay and Clad Restoration
For weld overlay and clad restoration of welded seams in clad material, filler metals
selected from the following table shall be used, unless other filler metals are specified on
the Purchaser’s equipment data sheet or vessel engineering drawing. The deposited weld
metal composition for alloy elements indicated in the following table shall be verified
using a proven quantitative analytical technique to be approved by the Purchaser.

Alloy Elements
Clad Materials Weld Filler Metals*
To Be Analyzed **
13 Percent-Cr (Type 410S or 405)
Design temperature below Type 309L None
600oF (316oC)

Design temperature equal or above Inconel 182 or None

600oF (316oC) Inconel 82 or
Inco-Weld A
Austenitic Stainless Steels Types 304, 1st Layer; Type 309L or Cr, Ni, Mo, Cb(Nb), Ti, C
304L, 316, 316L, 321, 347 309LMo (for L grade)

2nd Layer; matching Cr, Ni, Mo, Cb, Ti,

electrode C (for L grade)
Monel 400 1st Layer; Nickel alloy or Ni, Fe, Cu
Monel 190 or Monel 60

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Alloy Elements
Clad Materials Weld Filler Metals*
To Be Analyzed **

2nd Layer; Monel 190 or Ni, Fe, Cu

Monel 60
Note * Inconel 82 (SFA 5.14, ERNiCr-3), Inconel 182 (SFA 5.11, ENiCrFe-3), Inco
Weld “A” (SFA 5.11, ENiCrFe-2), Monel 60 (SFA 5.11, ERNiCu-7), Monel
190 (SFA 5.14, ENiCu-7).
Note ** The measured deposited weld metal chemical composition for elements
indicated shall be within the nominal ranges specified per ASME Sect. II, Part C.
5.3 General Welding Requirements

5.3.1 Cleaning Requirements :

• Weld bevels and an area at least 1 inch (25 mm) on either side shall be absolutely
clean of any foreign matter including paints, grease, oil, frost, dust or other processing
and environmental contaminants including condensed moisture.
• Grinding and cleaning of alloy steels, stainless steels and nonferrous metals shall be
performed using only tools that do not leave detrimental deposits/contaminants on the
base metal surface. Aluminum oxide or silicon carbide grinding media and austenitic
stainless steel wire brushes shall be used. This abrasive tooling shall not have
previously been used on other than the material to be cleaned.
• Nickel based alloy and copper based alloy weld joints shall be chemically cleaned
with a non-residue light solvent immediately prior to welding. This chemical cleaning
shall also be performed after any mechanical surface cleaning, such as brushing, is
performed during the course of welding.
• Double-welded groove joints shall have the root passes back-gouge removed to sound
metal on the reverse side before proceeding with welding on that side.
• Each pass shall be cleaned free of slag and/or scale before the next pass is deposited.
Each weld layer shall be free of slag inclusions, cracks, porosity. and lack of fusion.
• Deoxaluminite weld-through primer does not require removal when applied in
accordance with the Manufacturer’s instructions. Use of the AACCO brand is
preferred. Drips or runs in the path of the weld joint shall be removed.

5.3.2 Workmanship Requirements :

• Welding techniques shall be selected to ensure that specified dimensional tolerances
for straightness and out-of-roundness are not exceeded. If such tolerances are not
stated in the drawings, standards, or specifications, the applicable section of the
relevant Code shall govern.

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• All arc strikes, starts, and stops shall be confined to the welding groove. Arc strikes,
starts, and stops outside the groove shall be dressed by grinding and shall be examined
by magnetic particle or dye penetrant techniques.
• Maximum undercut of the base metal of equipment welds shall be the lesser of the
requirements of 0.0394 in. (1 mm) or t/4 (t is the nominal weld thickness less
reinforcement).

5.3.3 Backing Gas and Back Purge :

• All single-side welded groove joints in nickel alloys, stainless steel, and ferritic alloys
containing chromium greater than 1.5% by weight shall be welded using a GTAW
root pass with an inert gas back-purge. The back-purge shall be maintained for a
minimum of two passes.
• The PQR shall state the composition and flow rate of both shielding and inert gas
backing, when used.
• Nitrogen shall not be used for back-purging of austenitic, ferritic, or martensitic
stainless steels. Nitrogen may be uses as a backing gas for duplex stainless steel
pending Purchaser approval.
• Deletion of backing gas shall be an essential variable for the WPS.
5.3.4 Automatic and Computer Controlled Welding
• For automatic welding processes, the position for groove welds shall be an essential
variable.
• For automatic and semiautomatic welding processes utilizing computer or
microprocessor control of electrical parameters, the welding controller and power
source equipment shall be essential variables.
5.3.5 Welding In Unfavorable Weather Conditions
All welding processes shall be protected from wind, rain, and other weather conditions
that can affect weld quality. The maximum wind speed at the weld joint during welding
shall be 5 mph.
Welding covered by this Specification shall not be performed when the ambient
temperature is below 5°F (-15°C).
The following requirements shall be observed and applied when welding is performed
during unfavorable weather conditions and at ambient temperatures below 50°F (10°C)
down to 5°F (-15°C).
• The work place shall be screened off by suitable means (e.g. tent or tent awnings) and
if necessary heated to 50°F (10°C) or higher. The weld joints shall be free of moisture
on all sides within 3 in. (75 mm) of the prepared joint edge.
• Welding shall not be performed when metal temperature is below 32°F (0°C).
• Welding consumable materials shall only be used in a perfectly dry condition. Drying
temperatures and times shall comply strictly with the manufacturer’s instructions.

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Each SMAW welder shall be equipped with a heated electrode holder. The electrode
holder shall be calibrated at intervals not exceeding six months.
5.3.6 Tack welds shall be made with a filler metal having a similar nominal chemistry to the
filler metal used for root pass welding.
5.3.7 Vertical welds not completely removed by back-gouging shall be performed vertically up
unless specifically approved by the Purchaser in writing.
5.3.8 Weld joints shall be prepared by machining, grinding, or thermal cutting including
plasma-arc cutting.
5.3.9 Double-welded groove joints shall have their root passes back-gouged to sound metal on
the reverse side before proceeding with welding on that side.
5.3.10 Permanent weld backing bars, consumable inserts and non-consumable insert rings are
prohibited for welding of pressure components except for aluminum materials.
5.3.11 Temporary backing bars and temporary rings shall match the chemical composition of the
base metal being welded. After welding is complete, these shall be removed to flush with
the base metal without undercutting.
5.3.12 There are special conditions for [flame or arc] thermal cut weld bevel preparation for
quenched and tempered steels, HSLA steels, steels containing greater than 0.5% by weight
chromium, SA-517 and SA-537 when provided as quenched and tempered, and SA-737
steels: These materials shall not be formed after thermal cutting of bevels unless the
thermal cut surfaces are machined or ground back a minimum of 1/16 inch (1.5 mm). In
any case, thermal cut bevel surfaces shall be ground to smooth, and any stress raisers from
gouging of the bevel surface during the thermal cutting operation shall be removed
immediately after the cutting operation is completed. Thermal cut and machined bevels
shall be 100% finish ground to clean white metal to remove all cutting oil and scale
residues.
5.3.13 Peening and shot peening are prohibited. The use of a needle gun for scale/slag removal is
not considered peening.
5.3.14 Welding Aluminum
• Electrode configuration shall be shown in the WPS and shall be considered an
essential welding variable.
• For all processes, the WPS shall contain a detailed cleaning procedure indicating joint
preparation prior to welding. All full-penetration joints shall be back purged with
argon or helium.

5.4 Dissimilar Metal Welds

5.4.1 Filler metals shall be selected per 5.2.8 of this Specification.
5.4.2 DMW are not permitted in hydrogen services or in wet sour services, as defined by
Purchaser.

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5.4.3 WPS shall indicate that prepared joint surfaces of DMW joints welded with austenitic
stainless steel or nickel alloys shall be chemically cleaned with a non-residue light
chemical solvent immediately prior to welding.
5.4.4 For all weld processes, the WPS shall contain a detailed cleaning procedure indicating
joint preparation prior to welding.
5.4.5 All full-penetration joints shall be back purged with argon or helium.
5.5 Clad Plate and Overlay Welding
5.5.1 Filler metals shall be selected per 5.2.9 of this Specification.
5.5.2 Weld overlay and clad restoration shall consist of at least two layers. For austenitic
stainless steel overlay, type 309L (or 309LMo) filler metal shall be used for the first layer,
and matching electrodes shall be used for subsequent layer(s). The backing plate/joint of
restoration welds shall be welded with matching electrodes, and the weld groove in the
backing material on the clad side shall be filled to not less than flush with the backing
plate surface with a maximum reinforcement of 1/16 in. (1.6 mm). The deposited ferritic
weld metal shall not contact any clad material.
5.5.3 Certain welding procedures may be capable of attaining the required thickness and
chemical composition using a one layer technique. In this case, complete deposit
chemistry testing and metallographic documentation shall be required for qualification,
and prior written approval for use of a one-layer technique shall be obtained from the
Purchaser.
5.5.4 PQR for weld overlay deposits shall include complete chemical analysis of the overlay.
Chemical analysis for qualification shall be obtained by laboratory methods. Specimen
material for chemical analysis shall be taken at a depth of the specified overlay thickness
below the finished deposit surface. This depth shall not be less than 5/64 in. (2.0 mm)
using the prepared surface or side drilling techniques as illustrated in QW-462.5(a).
5.5.5 Chemical verification for production weld overlay and clad restoration of welded seams in
clad material is required. The deposited weld metal chemical composition shall be
measured at a depth of the cladding thickness from the finished deposit surface not less
than 5/64 in. (2.0 mm). Weld metal composition shall be verified using a proven
quantitative analytical technique approved by the Purchaser. If necessary, a repair
procedure shall be submitted to the Purchaser for review and approval.
5.5.6 The frequency of chemical analysis for production clad restoration welds shall be one
analysis for each procedure used and one analysis representative of each seam welded in
production. If any weld sample is deficient, all welds shall be verified. If repair becomes
necessary, a repair plan including WPS & PQR shall be submitted to the Purchaser for
review and approval.
5.5.7 The frequency of chemical analysis for production overlay welds shall be one sample
taken at the beginning of each overlay sequence (for each can section, head, exchanger
section, nozzle) and at least two samples taken during the later part of the overlay
sequence, and these sample locations should be selected by the Purchaser’s Inspector.

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5.5.8 Monel overlays shall have a maximum iron content of 5.0 %.

5.5.9 The cladding on clad plate shall be stripped back by a minimum of 1/4 in. (6 mm) from the
weld joint edges before welding of the backing plate. In the case of longitudinal and
circumferential welds for pressure vessel shell courses, the cladding shall be removed by
machining. Plasma arc gouging followed with grinding may be used for stripping
cladding at other locations. Clad-stripped surfaces shall be tested for removal of the clad
material by copper sulfate etching. Copper sulfate residue shall be thoroughly cleaned
before welding. Removal of clad shall not reduce the base metal thickness more than 0.04
in. (1 mm) below the design thickness.
5.5.10 Welds in the backing plate of clad material shall be welded, with matching nominal
chemistry electrodes, to not less than flush with the backing plate surface on the clad side
and maximum 1/16 in. reinforcement. The deposited ferritic weld metal shall not contact
the cladding material.
5.5.11 The finished surface of weld overlays deposited using either automatic or manual methods
shall be 100% liquid penetrant examined in accordance with ASME Code Section VIII,
Appendix 8. For vessels, this includes the overlay required to cover welds between shell
courses and around nozzles.
5.6 Preheat And Interpass Temperature
5.6.1 Preheat and interpass temperatures shall be in accordance with the applicable Codes and
supporting PQR. The minimum preheat requirement is also applicable for thermal
gouging, thermal cutting, and tack welding. The preheat temperature used in production
shall not be less than that used for the supporting PQR.
5.6.2 Where possible, the preheat temperature shall be measured through the full thickness of
the material on the side farthest away from the preheat source. Preheat temperature shall
be measured at a point not less than 3X the base metal thickness (3T) from the outermost
edge of the weld joint.
5.6.3 Carbon and ferritic steel shall be preheated to 175°F (79°C) minimum, when the surface
of the material is wet or damp within 3 in. (75 mm) of the weld bevel.

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5.6.4 The minimum preheat and maximum preheat and interpass temperatures for base metals
shall be per the following table :
Minimum Preheat Maximum Preheat
Base Metal Group (1) Temperature and Interpass
[ F / (C) ] Temperature
[ F / (C) ]

Carbon steels; P-1, Grp.1,2,3 600 / (315)

C content > 0.30%, or T at joint > 1 in. (25.4 mm), or 200 / (93)
highly restrained joints (2)
All others 50 / (10)
Low alloy steels; P-3, Grp.1,2,3 600 / (315)
Nom UTS > 70 ksi, or T at joint > 0.625 in (15.9 200 / (93)
mm), or highly restrained joints (2)
SA 302 and SA 533 materials, all T 300 / (149)
All others 50 / (10)
Low alloy steels; P-4, Grp.1,2 600 / (315)
Nom UTS > 60 ksi, or T at joint > 0.500 in (12.7 250 / (121)
mm), or highly restrained joints (2)
All others 175 / (79)
Low alloy steels; P-5A, P-5B,Grp.1 650 / (343)
Nom UTS > 60 ksi, or both Cr content > 6.0% and T 400 / (204)
at joint > 0.500 in (12.7 mm), or highly
restrained joints (2)
All others of this P-# 300 / (149)
Stainless Type 410; P-6,Grp.1 400 / (204) 600 / (315)
Stainless Type 410S; P-7,Grp.1 300 / (149)
Stainless Type 405 50 / (10) 500 / (250)
Alloy 20Cb3 50 / (10) 350 / (177)
CA6NM 500 / (260)
Thin sections 50 / (10)
Thick sections, or high restraint (2) 200 / (93)
Austenitic stainless steel (P-8) 50 / (10) 350 / (177)
Duplex stainless (P-10H) 50 / (10) 300 / (149)
Ni-Cu Alloy 400 50 / (10) 300 / (150)
Alloy C-276, Alloy 600, Alloy 625, Alloy 800, 800H, 50 / (10) 350 / (177)
800HT
(1) Alloys not listed in the table shall be per agreement with Purchaser.
(2) highly restrained joints/materials (e.g.: at nozzles, high load attachments)

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5.6.5 Preheat and interpass temperatures shall be determined by temperature-indicating crayons,

contact pyrometers, thermocouples, or other equally suitable means. Temperature
indicating crayons used on austenitic stainless steels and nickel-base alloys shall not cause
corrosive or other harmful effects to the base metal. The indicating crayons shall not
contain more than 1% by dry weight of total halogens or sulfur or 200 ppm by dry weight
of inorganic halogens. It is the Supplier's responsibility to determine suitable brands and
melting temperatures that may be used. This information shall be made available to the
Purchaser upon request.
5.6.6 When the specified preheat temperature is 300°F (149°C) or higher, the metal shall be
maintained at or above the preheat temperature until the weld is completed. If welding is
interrupted prior to that, the weld shall be covered with adequate insulating material to
ensure slow cooling. The partially completed weld shall be 100% examined by magnetic
particle testing before welding is resumed. Preheat/interpass temperature maintenance
during welding of the root and hot passes shall not be interrupted.
5.6.7 Performance of intermediate stress relief (ISR) and dehydrogenation treatment (DHT)
requires Purchaser approval.
5.7 Post Weld Heat Treatment
The following requirements are in addition to the applicable Code requirements for PWHT :
5.7.1 Ferritic steel materials shall be cooled to room temperature before PWHT.
5.7.2 A continuous record of the temperature indicated by all thermocouples shall be made on
recorder charts. A copy of these charts shall be included in the fabrication and test
records furnished to the Purchaser.
5.7.3 Post weld heat treatment (time and temperature) shall be considered an essential variable
for P-3, P-4, P-5 and P-6 materials. A decrease in time of more than 15% and/or
temperature of more than 10% from the PQR values shall require additional PQR testing.
5.7.4 Intermediate stress relief, if required, shall be performed at 1150°F (621°C). Low
temperature stress relief or de-hydrogenation treatment (performed at approximately
600°F (316°C)) is not acceptable in lieu of ISR.
5.7.5 All welding, including supports, clips, and structural parts, shall be completed prior to
final heat treatment. Exceptions to this requirement require Purchaser approval and shall
comply with Code requirements.
5.7.6 If the Supplier plans to use a local post weld heat treatment, a detailed description of the
local heat treatment procedure shall be submitted to the Purchaser for review and written
acceptance prior to use. A minimum of four thermocouples shall be attached, both to the
outside and inside surfaces of the equipment.
5.7.7 The use of exothermic kits is prohibited.
5.7.8 No welding shall be performed after post weld heat treatment without the specific written
approval of the Purchaser.

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5.7.9 On all equipment subject to PWHT, the item shall be prominently marked with paint on
two sides with white paint in block letters as follows : “PWHT - DO NOT WELD,
HAMMER, OR DEFORM”. The paint used shall not be harmful or detrimental to the
base metal and shall be compatible with both the primer and the finish paint.
5.8 Repair
5.8.1 Major defects in weldments, base materials, casting, and the like, shall not be repaired
until the Purchaser approves a general repair plan. The written plan shall include a
dimensioned detail sketch of defect location and extent, type of defect, how defects will
be removed, how removal will be verified, joint cleaning, the qualified welding procedure
to be used, conditions for subsequent heat treatment, and nondestructive examination
practice.
5.8.2 Repair of minor surface and minor welds defects by chipping, grinding and gouging shall
be permitted provided the thickness is not reduced below required minimum thickness.
Prepared surfaces from removal of defects and removal of attachments shall be verified by
magnetic particle or liquid penetrant examination.
5.8.3 Removal of defects by gouging shall always be followed by grinding to absolutely clean
metal, and grinding shall remove any stress raisers from gouging to a smooth contour.
5.8.4 Magnetic particle or liquid penetrant NDE examination shall be used to verify removal of
defects.
5.8.5 Supplier shall indicate which submitted welding procedures may be used as repair
procedures.
5.8.6 Repair welding shall be performed only by qualified welders using qualified welding
procedures.
5.8.7 Repair Welding after PWHT
Any plan for repair welding after PWHT shall require Purchaser approval in writing.
The plan for weld repair after PWHT without subsequent heat treatment or stress relief
after repair welding shall include the following requirements : [ ref BPVC UCS-56(f) ]

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5.8.7.1 Temper Bead Technique

The temper bead welding technique shall be used for repair welding after PWHT.
Temper bead welding, procedure qualification, and performance qualification
shall be performed in accordance with ASME Section IX QW-290 Temper Bead
Welding.
Temper bead welding shall be stringer bead welding only.
Heat input during welding shall be strictly controlled
With reference to QW-410.61, the “surface bead placement” dimension shall be
1/16 in. (1.6 mm) maximum.
With reference to QW-410.62, “surface beads removal” shall be performed. The
temper bead weld reinforcement shall be grind removed to the surface contour of
the base metal using methods and technique that do not “burn” the metal surface.
5.8.7.2 For the case of weld repair of equipment without subsequent PWHT, using
preheat, when impact testing is not performed for original equipment
construction :
• This procedure is limited to P-1,Gr.1&2 and P-3,Gr.1&2 steels (excluding
Mn-Mo steels).
• The weld joint shall be preheated to 300 F (149 C) and the interpass
temperature shall be minimum 300 F (149 C). The preheat and interpass
temperature shall be verified at a distance not less than 4T from each edge of
the prepared weld joint. The maximum interpass temperature shall not exceed
600 F (316 C).
5.8.7.3 For the case that weld repair of equipment without subsequent PWHT, using
preheat, when impact testing is performed for original construction of equipment :
• This procedure is limited to P-1, P-3 and P-4 steels (excluding Mn-Mo steels).
• Repair of materials that require impact testing shall be welded using
procedures qualified with impact testing of weld metal and HAZ at or below
relevant equipment MDMT.
• The supplementary essential variables of ASME QW-250 apply.
• The weld joint shall be preheated to 300 F (149 C) and the interpass
temperature shall be minimum 300 F (149 C). The preheat and interpass
temperature shall be verified at a distance not less than 4T from each edge of
the prepared weld joint. The maximum interpass temperature shall not exceed
600 F (316 C).
• The PQR maximum heat input shall be calculated and monitored during repair
welding and shall have a 5% in process over-tolerance during welding.

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5.8.7.4 Repair General (all cases)

For SMAW welding, electrodes to be used shall be certified with diffusible
hydrogen classification H8 or lower.
Upon completion of welding, and without loss of preheat, the temperature of the
repair zone shall be raised to 500 F (260 C) minimum with a minimum 2 hour
holding time to ensure hydrogen bake-out. The hydrogen bake-out treatment can
be omitted if electrodes which are certified with diffusible hydrogen classification
H4 are used.
Shielding gas shall be certified to have a dew point no higher than –58 F (-50 C).
Repair welds and HAZ made without PWHT shall be MT or PT examined at not
less than 48 hours after the material has cooled to ambient temperature. NDE
required per original construction Specification shall also be performed.
If welding shall comply with NACE requirements, then additional relevant
hardness testing is required to verify compliance.

6.0 INSPECTION

6.1 Weld Quality and Weld Inspection

In cases where doubt exists about the quality of welding work, Purchaser reserves the right to
undertake random radiographic tests or other nondestructive or destructive weld examinations on
components supplied or on any such welding executed on the fabrication site.
Components having weld seams that are not in compliance with the minimum requirements of the
applicable approved Specification or Code shall be repaired or replaced at the Supplier's expense.
The costs of any re-examination of weld seams shall be borne by the Supplier, and the costs of any
consequent random examinations that may need to be undertaken shall be borne by the Supplier. If
additional defects in welds are discovered, all seams shall be inspected and the costs shall be borne
by the Supplier.
NOTE: Any additional testing and monitoring by the Purchaser is no release from adherence to the
relevant approved Specifications for the execution of welding work.
6.1.1 Additional Requirements for Special High-Quality Weld Joints
For special high quality welding work, when so defined in writing by the Purchaser, the
Purchaser reserves the right to apply the following additional conditions :
• Before the start of any welding, the Purchaser shall be notified three weeks in
advance. The Purchaser's representative/Inspector shall have the option to be present
to inspect the welding preparation and its execution.
• Sample welds, representative of the subject weld joints, shall be completed
beforehand upon request, when deemed necessary, in the presence of the Purchaser's
Inspector.

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• At the Purchaser's option, witnessing of performance qualification welding and testing

may be required.

6.2 General Nondestructive Examination (NDE)

The scope of nondestructive examination shall be in accordance with the Codes, Standards,
Equipment Specification and other documents cited in or issued with the Purchase Order.
6.2.1 All NDE shall be performed in accordance with written procedures that conform to the
applicable ASME Code.
6.2.2 Personnel performing NDE shall be qualified in accordance with the ASNT
Recommended Practice SNT-TC-1A, or documented equivalent. All NDE results shall be
interpreted by personnel qualified in accordance with Level II minimum or documented
equivalent. Certification of personnel shall be made available for review by the
Purchaser's inspector.
6.2.3 The minimum extent of examination shall be in accordance with the applicable Code,
Commodity Specification, or Purchase Order. In the case of pressure vessels, the ABB
Engineering Specification D-201, "Pressure Vessels" including all relevant attachments
shall apply. In the case of heat exchangers, the ABB Engineering Specification EA-201,
“Shell and Tube Heat Exchange Equipment” including all relevant attachments shall
apply..
6.2.4 All NDE results, including visual, shall be recorded and be traceable to the item
examined.
6.2.5 When radiographic examination is specified but is not practical, the Supplier shall propose
in writing an ultrasonic examination or an alternative nondestructive examination method
for approval.
6.2.6 The Purchaser reserves the right to approve all final radiographs and results of other
examinations and tests.
6.2.7 The attachment welds between structural components and pressure parts of quenched and
tempered carbon steel, high strength low alloy (HSLA) steel, and ferritic alloy materials
shall be examined by the wet fluorescent magnetic particle method after post weld heat
treatment. This requirement does not apply for 5% through 9% nickel steels.
6.2.8 All pressure containing equipment designed with 100% joint efficiency, irrespective of
material, shall have all nozzle and reinforcing pad attachment welds examined by
magnetic particle or liquid penetrant methods as applicable. This inspection shall also be
performed on the inside of all accessible nozzle attachment welds. This final inspection
shall be made after post weld heat treatment, if any.
6.2.9 All removed attachment areas (including backing rings) shall be examined by the
magnetic particle technique. If this is not possible, the liquid penetrant method may be
used.
6.2.10 Locations of nondestructive examinations shall be in accordance with the applicable
documents or as selected by the Purchaser's Inspector.

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6.2.11 Any welder or welding operator having a weld rejection rate exceeding 3% of their
deposited weld length shall be disqualified or shall be subjected to 100% non destructive
examination until the rejection rate reaches a level previously agreed upon between
Supplier and Purchaser's Inspector.
6.2.12 Supplier shall include all production NDE results in the final equipment data package.
6.3 Visual Examination
The Supplier shall visually inspect 100% of weld length after completion. Each weld shall be
uniform in width and size throughout its full length. The cover pass (final weld layer) shall be free of
undercut, course ripples, grooves, overlaps, abrupt ridges, slag, weld spatter and valleys.
The Supplier's inspection personnel responsible for performing visual inspections shall be adequately
trained in both welding and inspection and their visual acuity qualification shall be documented.

6.4 Magnetic Particle Examination (MT)

The following requirements are in addition to the applicable Code requirements for magnetic particle
examination :
• For examination by the prod method, the control switch shall be built into the prod handles to
prevent arcing.
• Arc strikes resulting from magnetic particle examination shall be removed by grinding.
• Only the AC yoke method shall be used after final PWHT.
• Permanent magnets or AC yokes shall be used on air hardening steels.
• Magnetic particle inspection shall not be used on 5% through 9% nickel steels.

6.5 Liquid Penetrant Examination (PT)

The following requirements are in addition to the applicable Code requirements for liquid penetrant
examination :
• Liquid penetrant examination shall be used only for nonmagnetic materials and 5% through
9% nickel steels unless otherwise approved in writing by the Purchaser.
• Cleaning and developing solutions with a combined total residual sulfur and halogen content
greater than 1% by dry weight shall not be used. Supplier shall maintain documentation
showing compliance with this requirement for review by the Purchaser’s Inspector.

6.6 Radiographic Testing (RT)

The following requirements are in addition to the applicable Code requirements for radiographic
examination :
• Only fine grain film shall be used.
• Only lead screens shall be used.

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• Use of penetrameters other than those specified in the ASME Code, Section VIII (such as
DIN/IIW wires) is permissible. However, the thickness sensitivity and hole sensitivity shall be
equivalent to those required by the ASME Code, and prior written approval shall be obtained
from the Purchaser.
• Single-film viewing shall be used. The film density shall be 1.8-to-4.0 for an X-ray source
and 2.0-to-4.0 for a gamma-ray source. In those instances where the variable thickness makes
a single film impractical, double-film viewing may be used with Purchaser concurrence. For
the double-film technique, the film density shall be in the range of 2.6-to-4.0 for the double-
film combination, with a minimum density of 1.3 for each film.
• Radiography of welds in NPS 2-1/2 or smaller may be performed by the elliptical projection
technique. At least two separate exposures are required at locations 90 degrees apart.

6.7 Ultrasonic Examination (UT)

The following requirements are in addition to the applicable Code requirements for ultrasonic
examination :
• The weld shall be examined using least two different shear wave probe/transducer angles.
• Welds are not acceptable if the echoes from discontinuities exceed the reference curve.
• Each weld groove face shall be completely examined from both sides of the joint. Echoes
exceeding 20% of the reference curve shall be fully evaluated and accurately sized. Echoes
exceeding 20% of the reference curve shall be recorded.

6.8 NDE of Weld Overlay and Clad Restoration

100% of the final surface area of weld overlay and clad restoration welds shall be liquid penetrant
inspected. Examination shall be performed after PWHT if PWHT is applied. LP examination and
acceptance standards shall be per ASME Section VIII, Appendix 8.

6.9 Hardness Testing

6.9.1 Hardness Testing Technique
Hardness testing may be performed using Vickers (HV, 10 kgf or less), Brinell (HBW), or Rockwell
(RHA, RHB) Standard methods. Hardness data may be provided in HB, HV, or RHB units or unit
equivalents of these per ASTM E-140.
When hardness of weldment cross sections is measured, the location of hardness indents shall be
generally consistent with illustrations in API 582, Figure 12.1, or API 934, Figure 7-1, or NACE RP
0472, Figures 2 & 3, or NACE 8X194, Figures 1 & 2.
When production hardness testing of weldment surfaces is measured in shop or field locations,
hardness testing shall be performed using the Telebrinnel portable hardness testing apparatus or
approved equivalent. Alternative shop/field hardness testing methods may be proposed by the
Supplier, but the accuracy and precision of the proposed method shall be supported with documented
comparative hardness data referenced to a laboratory Standard method and a written testing
procedure.

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6.9.2 Welding Qualification Hardness Testing

When hardness testing is required for production, the laboratory measured hardness of base metal(s),
weld metal, and heat affected zone (HAZ) of base metal(s) shall be reported in PQR.
6.9.3 Production Weld Hardness Testing
6.9.3.1 The production weld hardness tests shall be performed for the following materials
and services :
• Plain carbon and carbon manganese steels (ASME P-1) when specified on the
Purchaser’s Equipment Data Sheet or Engineering Drawings, or when post
weld heat treated (PWHT).
• Low alloy steels (ASME P-3 and P-4, P-5, and P-9).
• Ferritic stainless steels (ASME P-6).
• SAW using an F8XX [550 MPa, 80 ksi min. UTS] or higher flux/wire
classification.
• SMAW using an E80XX [550 MPa, 80 ksi min. UTS] or higher flux/wire
classification.

6.9.3.2 Unless indicated otherwise, hardness acceptance shall be per the following table :
Alloy Steel Maximum Hardness for
Acceptance

HB HV HRB

P-1 200 211 94

P-3, P-4 225 236 98
P5A, P5B (except 9Cr1MoV grades) 235 247 100
P5B (F91, P91, T91, WP91) 248 261 102
P5C 235 247 100
P-6 235 247 100
P-7 235 247 100
P-10A, P-10B, P-10C, P-10F 225 236 98
P-11 225 236 98
The Purchaser shall be made aware of all hardness readings in excess of table
values. Any corrective action shall be reviewed with Purchaser before
proceeding.
6.9.3.3 The hardness test frequency shall be as follows :
• One hardness test for each longitudinal seam of each course.

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• One hardness test for each circumferential seam.

• One hardness test for each nozzle to shell weld.
6.9.3.4 The hardness test indent location shall be at or near the center of the weld or
surface to be tested on the side exposed to the process environment. When this is
not practical, the test shall be made on the opposite side. The surface shall be
prepared in accordance with ASTM E-10.
6.9.3.5 Nonferrous materials and austenitic stainless steel welds shall not require
hardness testing unless specifically requested, in writing, by the Purchaser.
6.9.3.6 Perform the hardness testing after PWHT if PWHT is applied.
6.10 CVN Impact Testing
6.10.1 When CVN impact testing is required per Code, testing shall include testing of both weld
metal and HAZ of each parent material.
Testing for ferritic materials is required at minimum design metal temperature (MDMT)
or lower.
The CVN impact energy acceptance for weld metal and HAZ shall be not less than that
specified for the base metal. The minimum individual specimen impact energy shall be
75% of the average (for 3 specimens) required for parent metal acceptance.
Impact specimen material for welding procedure qualification shall be obtained from base
material of a similar product specification ( ASTM, or ASME Section II, or other
documented similar specification ), class, and grade as the base material to be used in
production.
When CVN testing is required by the ASME Code or by Purchaser requirement, the
ASME Section IX QW-250 supplementary essential variables for the respective welding
process shall apply.

7.0 SUPPLIER DOCUMENTATION

The Supplier (and each Sub-Contractor to the Supplier) shall submit documents for all fabricated
equipment and components in accordance with requirements stated in the Purchase Order.
Compliance with this Specification and approval of weld maps, WPS/PQR, and any mill test reports by the
Purchaser shall in no way relieve the Supplier of the responsibility to provide welds which are sound and
suited for the intended service.

7.1 Weld Maps

Weld Maps shall contain the following information :
• An illustration (sketch or outline drawing) of the equipment showing weld joints.
• Equipment name, tag numbers, PEMEX Purchase Order number.
• All weld locations with corresponding (or typical) WPS numbers identified.

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• Typical joint details with weld symbols.

• Materials of construction and thickness at welds for shell, heads, nozzles.
• Requirements for CVN impact testing, hardness testing, and PWHT, when applied.
If the above information is included on a “General Arrangement Drawing”, this drawing may be
substituted for a weld map. Equipment detail drawings are not acceptable substitutes for weld maps.

7.2 Un-Listed Base and Filler Metal for Welding Qualification

7.2.1 Welding procedures for base metals to be used in production but which are not listed in
ASME Sect. IX, QW-422, shall be qualified individually.
7.2.2 Welding consumables to be used in production that are not listed in ASME Sect. II, Part
C, shall be qualified individually. Welding consumables with an AWS/ASME “G”
classification suffix shall be qualified individually.
7.3 Welding Procedure Specification (WPS)
7.3.1 WPS shall be qualified in accordance with ASME Sect. IX or Purchaser approved
alternate formal Code or Standard. Each WPS shall include as a minimum all the
information contained in the Sect. IX Form QW-482.
7.3.2 WPS(s) submitted to the Purchaser shall be clearly identified with the Purchase Order
number.
7.3.3 Revisions to WPS/PQR and other procedures made to include Purchaser’s comments or
other comments shall be suitably identified. Supplier’s revisions to WPS can be detailed
on a project specific addendum to the WPS.
7.3.4 When CVN testing is required by the ASME Code or by Purchaser or Owner requirement,
the supplementary essential variables cited in ASME Section IX Article II for the
respective process shall apply.
7.4 Procedure Qualification Record (PQR)
7.4.1 Each PQR shall include as a minimum all the information contained in the Sect. IX Form
QW-483.
7.4.2 If in the opinion of the Purchaser a supporting PQR fails to reasonably simulate actual
conditions during production welding, re-qualification or additional qualification tests are
required.
7.4.3 For the case that ASME or ASTM base materials are used in production, welding
procedure shall be qualified using a base metal of the same type, class, or grade or another
base metal listed in the same ASME Sect. IX QW-422 P-Number and Group Number as
the base metal to be welded in production.

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7.4.4 For the case that materials not listed in ASME Sect. IX QW-422 are used in production,
welding qualification shall be performed using the same Manufacturer’s material/product
Specification, grade or class, to be welded in production. PQR using unlisted base
material shall support only WPS using material of the same material/product specification.
7.4.5 When hardness testing is required for production welds, the PQR shall include hardness
test results. Hardness data may be provided in HB, HV, or RHB units or standard
conversions of these per ASTM E-140. The hardness acceptance shall be the same as for
production welds. The hardness test results shall include the weld metal and HAZ
hardness for each P-Number, Group Number, material included in the joint. A minimum
of three readings each in the weld metal and respective heat affected zone shall be
reported.
7.4.6 CVN impact toughness test data is required for PQR when :
• Impact toughness testing is required for production.
• When otherwise required by the applicable Code.
• When required by Purchaser or Owner Specification.
7.4.7 When impact testing is required by the applicable Code, the welding procedure
qualification shall include CVN impact testing of the weld metal and heat affected zone
(as applicable) at the minimum design metal temperature (MDMT) or lower. The impact
test results shall be recorded in the PQR or in an addendum to the PQR.
7.4.8 Note Purchase Order requirements for submission of stainless steel filler metal
manufacturer’s CMTR(s) with each associated PQR, for each filler metal heat/lot to be
used in production. This is needed to evaluate the filler metal ferrite number/percent.
7.4.9 Performance qualification for all welders and welding operators shall be available to the
Purchaser’s Inspector for review.
7.5 Repair Welding Plan
Normally, repair welding documentation only needs to be submitted in the event of major repairs, as
defined per Code, Specification, and/or at the Inspector’s option.
When major repairs are required, the Supplier shall submit a fabrication repair welding plan for
repair of defects in equipment and piping components. As a minimum, the repair plan shall detail the
repair related documentation, defect description, how defects will be removed, how removal will be
verified, joint cleaning, the qualified WPS to be used, the conditions for subsequent heat treatment,
and applied NDE practice.

7.6 Overlay and Clad Restoration Plan

The fabrication plan for weld overlay and clad restoration of equipment components shall detail base
metal and weld joint preparation and examination, welding practice details, and applied NDE
practice.

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7.7 Post Weld Heat Treatment (PWHT)

As a minimum, the furnace PWHT procedure shall detail the furnace type, the method of heating and
type of equipment, method of thermocouple attachment, method and location of supports, heating
and cooling rate and rate tolerances, holding temperature and temperature tolerances, and holding
time and tolerances.
Local PWHT Procedures
As a minimum, local post weld heat treatment procedures shall detail the joint
configuration for heat treatment, the equipment to be used, thermocouple placement,
heating and cooling rate and rate tolerances, holding temperature and temperature
tolerances, and holding time and tolerances..

7.8 NDE Procedures:

Supplier’s NDE procedure(s)as relevant for purchased equipment.

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