Petroleum Development Oman L.L.C.

Welding of Pressure Containing Equipment and Piping

(Amendments and Supplements to IOGP S-705 V 1.0 )

Document ID SP-1173

Document Type Specification

Security Unrestricted

Discipline Material & Corrosion

Owner CFDH of Materials Integrity – UEC

Issue February , 2021

Version 3.0

Keywords: This document is the property of Petroleum Development Oman, LLC. Neither the whole nor any part
of this document may be disclosed to others or reproduced, stored in a retrieval system, or transmitted in any form
by any means (electronic, mechanical, reprographic recording or otherwise) without prior written consent of the
owner.
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i DOCUMENT AUTHORISATION

Authorised For Issue

Document Authorisation

Document Owner Document Custodian Document Author

UEC UEC1 UEC15
Nasser Al Behalani Talal Al Nabhani Manish Suresh Kulkarni

Behlani, Nasser UEC NABHANI,TALAL UEC1 Kulkarni, Manish Suresh UEC15

Date : 01-03-2021 8:59 AM Date : 11-02-2021 9:11 AM Date : 08-02-2021 9:16 AM

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ii REVISION HISTORY
The following is a brief summary of the recent revisions to this document. Details of all revisions prior to these are
held by the issuing department.

Version No. Date Author Scope / Remarks

1.1 04/06/2000 OTT/15 Revision and re-formatting of original issue of ERD 43-01.
1.2 25/12/2004 TTO/15 Appendix D added, minor textual corrections.
1.3 11/05/2008 UEC/111 Updated based on past experience
1.4 16/9/2012 UEOC15 Complete rewrite, based on DEP 30.10.60.18-Gen
1.5 17/01/2016 UEOC15X Complete rewrite, Amendment to DEP 30.10.60.18-Gen
2.0 16/10/2019 UEC15 Amendment to DEP 30.10.60.18: 2017
Complete rewrite ,Amendment/ supplements to
3.0 07/02/2021 UEC15
IOGP S 705

iii RELATED BUSINESS PROCESSES

Code of Practice Business Process (EPBM 4.0)

CP-117 Project Engineering
CP-190 Quality Management System for Project Delivery
CP -208 Corrosion Management code of Practice

RELATED CORPORATE MANAGEMENT SYSTEM (CMS) DOCUMENTS

The related CMS Documents can be retrieved from the Corporate Management Portal (CMS).

Document Number Document Title

Specification for Quality Assurance Requirements for Product and
SP-1171
Service
Non-Destructive Examination ( Amendments/Supplements to ASME
SP- 1176
BPV Code section V)
SP- 2069 Specification for Pressure Vessel

SP-2070 Specification for Air Cooled Heat Exchanger

SP 2187 Specification for Storage Tanks

SP 2161 Materials Selection & Corrosion Control for Surface Facilities

SP 2170 Specification for Shell & Tube Heat Exchangers

SP 2279 Specification for Flare systems.

SP 2342 Specification for Standard Piping Items

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TABLE OF CONTENTS

i DOCUMENT AUTHORISATION ....................................................................................................... 3

ii REVISION HISTORY ......................................................................................................................... 4
iii RELATED BUSINESS PROCESSES ................................................................................................... 4
TABLE OF CONTENTS ............................................................................................................................. 5
Introduction ................................................................................................................................................ 6
1. Scope .................................................................................................................................................. 7
2. Normative References .......................................................................................................................... 7
4 General Welding Requirements ............................................................................................................. 8
5 Welding processes ............................................................................................................................... 8
6 Welding Consumables( Filler metal and Flux) ........................................................................................ 8
7 Shielding and Purging Gases................................................................................................................. 9
8 Preheating and Interpass Temperature ................................................................................................... 9
9 Post Weld Heat Treatment( PWHT) ...................................................................................................... 9
11 Special Procedure Qualification Requirements/ Testing ........................................................................ 10
12 Other Items ....................................................................................................................................... 11
Annex B Weld Overlay and Clad Restoration( Back cladding) ..................................................................... 12
Annex D User Feedback Form .................................................................................................................. 13

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Introduction
i) DISTRIBUTION , INTENDED USE AND REGULATORY CONSIDERATIONS

Unless otherwise authorised by PDO, the distribution of this SP is restricted to Contractors and
Manufacturers/Suppliers nominated by PDO. Any authorized access to this SP does not constitute an
authorization to any documents, data or information to which the SP refers.

ii) SUMMARY OF MAIN CHANGES

This specification is a revision of the Specification of the same number dated December 2019.
This specification is an amendment / supplementation of International Assosciation of Oil and Gas
Producers( IOGP) specification S-705 Version 1.0 published in June 2020.

The clauses of IOGP S-705 not supplemented or amended in this specification shall be considered
valid and applicable.

This specification shall be applied as a standalone document as modified in this SP and shall not be
read with any of the following documents:

IOGP S-705D: Data sheet for Welding of Pressure Containing Equipment and Piping;
IOGP S-705Q:Quality Requirments for Welding of Pressure Containing Equipment and Piping;
IOGP S-705L: Information Requirements for Welding of Pressure Containing Equipment and Piping.

iii) PRECEDENCE OF DOCUMENTS

If documents are conflicting, the following precedence of documents shall apply:

 First level - Statutory laws and regulations;

 Second level – This Specification;
 Third level – IOGP S -705;
 Fourth level – API RP 582;
 Fifth level – International codes and cross-referenced documents.

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1. Scope
1.1 Modify the clause as the following
b) Refer to Tank specification SP 2187 for storage tanks for Welding requirements.

Add new item e as the following

e) This specification shall be applicable to E &I items only for process containment parts (wetted parts)

2. Normative References
Add to the clause 2.0 as the following:
ASTM Standards

Standard Test Methods for Detecting Susceptibility to Intergranular Corrosion in Wrought, ASTM G 28
Nickel-Rich, Chromium-Bearing Alloys
Standard Test Methods for Pitting and Crevice Corrosion resistance of Stainless Steels and ASTM G48
related Alloys by the Use of Ferric Chloride Solution
Standard Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, ASTM A 380
Equipment, and Systems
Material verification programme for new and existing alloy piping systems. API 578

3. Terms and Definitions

Certain terms and abbreviations used in this document are defined below and are supplement to those provided in API
582, S-705
General Definitions
The Contractor The party which carries out all or part of the design, engineering, procurement, construction,
commissioning or management of a project, or operation or maintenance of a facility. The
Company may undertake all or part of the duties of the Contractor
Fabricator The party which carry out fabrication activities.
The party which manufactures or supplies equipment and services to perform the duties specified
Manufacturer/ Supplier by the Contractor
The Company( PDO) Petroleum Development Oman LLC. The Company will generally specify the technical
requirements.
MCI TA1 Manager Material corrosion and Intergrity TA1
Shall Indicates a requirement. Any deviation to a requirement shall be approved by Nominated
Company Welding TA 2 .
Specific Definitions
Nominal thickness  Butt joint: parent metal thickness, which for joints between dissimilar thicknesses is
that of the thinner material.
 Fillet weld: parent metal thickness, which for joints between dissimilar thicknesses
is that of the thicker material.
 set-on branch connection: thickness of branch pipe
 Set-through branch connection; thickness of main pipe.
Outside Diameter  For butt welds, Outside diameter of components.
(OD)  For branches (including weld-o-lets), OD means outside diameter of the
branch/weld-o-let at the weld toe.
Corrosion Resistant (SS, superaustenitic stainless steel DSS,SDSS, Ni alloys). In general alloys with min 13%
alloys ( CRA) Chromium in chemical composition.
Weld repair rate Repair rate is based on the number of completed pipe welds. A rejection is considered any weld
(Piping) that requires a repair. The repair rate is defined as the number of repairs per number of completed
and NDT tested (RT/UT) welds.
Weld repair rate The Repair rate is based on the total linear weld distance on a per-meter (or per-foot) basis. A
(equipment) rejection is considered any weld that requires a repair within a 1 m (3.3 ft) segment. The repair
rate is defined as the number of repaired segments per total number of one-meter segments.

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4 General Welding Requirements

4.3 Replace the clause as the following
All WPS shall be approved by Company Welding TA2 and available for production welds including repair
welds. Previously qualified PQR may be accepted, if PQR meets the requirements of this specification.

4.4 Add to the clause as below

Contractor shall submit the following for approval of the Company
(a) Fabricator's records including monitoring of production welds;
(b) Fabricator's welding inspection report including production tests/weld history sheet.

4.8 Procedure Qualification Record ( PQR)

4.8.2 Delete this subclause.
4.8.3 Replace the caluse as the following
The PQR shall be endorsed by PDO Welding TA2 or accridiated independent third party agency.

4.13 Welding and Welding Operator Qualification

4.13.2 Add to the clause as the following
Welder /Welding operators shall be qualified as per this specification.
4.13.3 Replace the clause as the following
All welders and welding operators performance test coupons shall be visually examined (including
discolouration checks for CRA materials) and radiographed. Bends test shall be carried out for performance
qualifications of GMAW or FCAW processes.

4.15 Welding Coordinator Qualification

Add to the clause as the following
Alternatively,Contractor’s approved Welding Engineer shall be responsible for welding coordination.

5 Welding processes
5.1 Acceptable Welding Processes
Modify the Notes of Table 7 as the following
Replace Note 3 as the following
SMAW is not permitted for root pass in single sided welds where root pass is not removed.
Add Note 5 as the following
GMAW shall be applied only as mechanised or automatic process. GMAW welds shall be inspected by
UT. Semi automated GMAW shall not be used except for weld overlay clad restoration.
Add Note 7 as the following
GTAW shall be used for root run of small bore piping upto dia 3 inch ( DN 75) and for sour service piping
applications.

5.2 Limitations of Fusion Welding Processes

5.2.3 GMAW-S
Add item g)
g) GMAW-S shall only be permitted for nonsour services and MDMT warmer than -29 Degree
Centigrade.
5.2.5 FCAW
5.2.5.2 Add to the subclause as the following
FCAW-G shall only be permitted for nonsour services and MDMT warmer than -29 Degree Centigrade.

6 Welding Consumables( Filler metal and Flux)

6.1 General
6.1.9 Replace the subclause as the following:
Welding consumables shall be purchased from PDO AVME approved consumable manufacturers or
classification society (e.g. DNV, TUV, Lloyds ) approved consumable manufacturers.

6.2 Disimilar Welding

6.2.3 Add to the caluse as the following:
Dissimilar welding within different P numbers shall subject to Company Material TA2 approval.Contractor
shall record dissimilar weld details in Dissimilar weld register.

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7 Shielding and Purging Gases

7.3 Replace 7.3 d) as the following:
The Oxygen content of the purged gas for each production weld shall be less than 500 ppm or as per qualified
PQR, whichever is stringent.. Method of measuring Oxygen in purging gas shall be as per the qualified PQR.

7.4 Add to the clause as following:

Maximum 2% Hydrogen in shielding gas may be accepted for weldoverlay applications, provided the weld
quality is demonstrated in PQR to the requirement of this specification.

7.8.4 Add to the clause as the following:

Oxidation checks shall be carried out on pipe bore surface after attachment welds.

8 Preheating and Interpass Temperature

8.9 Add to the clause as the following:
Preheating to 50 Degree Centigrade shall be carried out if ambient temperature < 15 degree Centigrade and
in case of moisture/ condensation.

9 Post Weld Heat Treatment( PWHT)

9.11 Code Exemptions
9.11.1 Add to the clause as the following:
Exemptions from code requirement for PWHT shall be authorized by MCI TA1.
9.12 Replace as the following:
The PWHT shall comply with design code requirement and Table 6 of API 582, whichever is more stringent.

Add below rows to Table 6 of API 582 for P1 materials.

P. Material Nom. Service environment Holding Holding
Type thk. at Temperature Time
No.
weld
( Deg F) ( Hours)
1 Carbon All Ammonia, HTHA service, High pressure 1150 to 1200 1, Minimum
steel High temperature Hydrogen service

2 Carbon All Alkaline water with Carbonate 1200 to 1250 1, Minimum

steel

Add Note e) , When PWHT applied, attachment welds and branch welds shall be included.
PWHT for Piping Fabrication of Carbon Steel weldments shall be carried out as the following
Material Service Nominal PWHT requirement
thickness
of weld
Carbon (Sour) ≤20 mm PWHT is required, unless following conditions are met
steel piping Wet
1) WPS PQR is qualified on actual or higher thickness and with
weldments H2S
highest CE ( +0.03).
2) Preheat of 100 Deg. C shall be applied for thickness ≥ 12.7mm
>20 mm Mandatory PWHT

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11 Special Procedure Qualification Requirements/ Testing

11.1 General
11.1.1 Add to the clause as the following
PQR shall include following NDT tests

Butt Welds - Visual,MT/ PT, RT (and UT ,If any pass is welded with GMAW or FCAW process).
Fillet Welds- Visual, MT / PT.
Any weld, which fails to meet the acceptance criteria specified in applicable construction code, shall not be
permitted for further laboratory testing.

Each PQR shall include Hardness survey as per clause 11.5.4 and Macrotest as per clause 11.7.
PQRs for CRA materials shall include metallogrphic evaluation.

PQRs for piping application shall be carried out using piping components, in production welding position or
in 6G position.

For piping systems in high wet H2S / sour service, the Welding Procedure Qualification shall be carried out
on the same P-No. and Group-No. or same group and subgroup as used in production welding.

11.1.3 Add to the subclause as the following:

PQR of CRA materials shall meet corrosion testing requirements as below
Sl. Weldments of Materials Corroison Test details
1 SS 316/ 316L A 262 Pr E
2 Alloy 825 /625 ASTM G 28A shall be carried out and shall meet weight loss
requirement of maximum 0.9 mm/ year.

Corrosion testing shall be performed on as welded sample.

Add new clause 11.2.6 as the following:

11.2.6 Tube ID shall be inspected as per clause 7.8.4. Unacceptable discolouration shall treated as per
ASTM A 380.

11.3 Additional Procedure Qualification Requirements for Duplex and Superduplex Stainless Steels
11.3.6 Corrosion and Impact Testing
11.3 6.2 Corrosion Test

Add to item d) as the following:

Corrosion testing shall be performed on as welded sample.

11.4 Essential Variables

Modify Table 11 as below

Girth welds shall be interpreted as all type of welds.

Row Number 11 - Essentail variable: Consumable : Add to description as

A change in Brandnane, for corrosion and/or for sour service applications.

Row Number 23 Essential Variable : Heat input : Replace descition as :

Heat input shall not exceed +25% of average heat input or as defined by construction code whichever is
stringent.

11.6 Impact testing

11.6.3 Modify as the following
For Piping PQRs, the Impact testing shall comply with the Table 13 as below

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Table 13 Minimum Charpy V –notch Absorbed Energy Values

Material Test Temperature Minimum Average Minimum Single
Absorbed Energy Absorbed Energy
Non impact tested CS As per base metal requirements/design code
LTCS( e.g. ASTM -50 Degree Centigrade 27 J 21 J
A333 & ASTM A671
Only one result may be lower than 27 J.
Gr.CC65 CL 22,
ASTM A420, ASTM A multiplication factor of 1.5 applies to impact values for sub-size
A350) specimens, as defined in Table 3 of ASTM A333.
Alternatively as stated below
-46 Degree Centigrade 33 J 26 J
Only one result may be lower than 33 J.
A multiplication factor of 1.5 applies to impact values for sub-size
specimens, as defined in Table 3 of ASTM A333.
Other CS and LAS( As per code or base 27 J or design code, 21 J or design code,
e.g. #52,#60) material specification whichever is higher whichever is higher
Austenitic Stainless MDT( Refer cl. 11.6.2) Lateral expansion
steel minimum 0.38mm
22 Cr and 25 Cr As per QL1 of ISO 17781( Refer table 2 –ISO 17781)

11.9 Qualification of Repair Procedures

11.9.1 Replace the clause as the following
Repair welding shall be carried out by the original WPS/ PQR for zone C.
A separate PQR shall be qualified for the specific repair scenario for zone B (and for Zone C only if repair
welding process is different from original weld). Repairs on Zone A shall not be permitted.
Refer Figure 1 for repair methodology for all CRA materials single sided welds.
For double side CRA welding, repair welding shall be carried out by the original WPS/ PQR. A sepearte
PQR shall be qualified if repair welding process is different than used for original weld.
11.9.6 Add to existing clause as the following:
Impact test shall be carried out for butt welds according to 11.3.6.3.

12 Other Items
12.3 Weldoverlay and Clad Restoration( Back cladding)
Replace the clause as the following
12.3.1 Weld overlays shall be as per ASME Sec IX, Section 11 and as modified in Annex B.
12.6 Hardness testing – Production Testing
12.6.1 Replace the clause as the following
Hardness testing shall be carried out on 10% Production welds of CS sour service and for DSS welds.

12.11 Repair Welding

12.11.3 Replace the caluse as the following
For LTCS and CRA weldments, only one repair attempt shall be allowed in the same area.

12.12 Production Tests

Replace the clause 12.12.1 and 12.12.2 as the following
12.12.1 Production test coupon ( PTC) requirements shall be as per design code and Enginering specification.
12.12.2 Hardness test shall be carried out on PTC using Single cycle PWHT and Tensile & Impact tests shall
be carried out on PTC using additional two cycle PWHT.

12.13 Ferrite Control for Austenitic Stainless Steel Production Welds

12.13.1 Add to the clause as the following
SS, DSS and SDSS Production welds shall include ferrite test for 10% of the welds by a welder on per day
basis.Any noncompliance shall mandate 100% ferrite inspection of the day production, by the welder.

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Annex B Weld Overlay and Clad Restoration( Back cladding)

The requirements of annex B shall be considered mandatory.
B.1 General
B 1.1 Add to the clause as the following
Single layer overlays shall not be permitted unless approved by MCI TA1.

B1.7 Add to the clause as the following

The production test locations for overlay chemical composition shall be located at the surface.

If weld overlay is applied to restore the clad area of weld joints between clad components, at least one deposit
analysis per welding procedure per longseam and cicumferential seam in the vessel shall be performed.

If weld overlay is applied to the surface of equipment shells/dished end , deposit analyses shall be the greater
number of samples of the following:
( a) at least two analyses per 10 m2 (100 ft2) of overlay or fraction thereof;
( b) one analysis from each end of the shell/dish at locations that are diametrically opposed.

If weld overlay is applied to the surface of equipment components, deposit analyses shall be provided as
follows:
( a) one analysis for each welding procedure used;
(b) one analysis for each piece of equipment manufactured.
( c) at least one analysis for the smallest component welded with each procedure;
(c) at least one analysis for the largest component welded with each procedure.

If weld overlay is applied for surface repair of clad components or for restoration of surfaces where cladding
has been removed (other than weld seams), at least one deposit analysis shall be provided for each WPS.

B.1.8 Replace as the following:

For SAW and ESSC, with the exception of compensation of losses of alloying element due to welding arc
,deliberate additions of alloying elements through the flux shall be prohibited.

Add to the clause as the following

All clad restoration and repair areas shall be examined for UT disbondment as per Level C of ASTM A 578.

B 1.14 Replace as the following:

For austenitic stainless steel overlay, PQR shall include corrosion testing as per ASTM A 262 Practice E.

B6 Nickel- base Alloy( Other than Ni-Cu Alloy 400)

Add new clause B 6.3 as the following

B.6. 3 Weldoverlay PQR shall include corrosion tests as below

Sl. No Corrosion Test Acceptance criteria

1 ASTM G 28A Weight loss requirement of maximum 0.9 mm/ year.
2 ASTM G48 Weight loss requirement of max. 4.0 gm /meter square and no pitting more
Method A than 25 microns at 20 X magnification, when tested at 40 +1/-1 degree
Centigrade.

Add new clause

B. 7 Pressure Equipment and Piping fabricated with Overlay, clad.

B.7.1.1 End preparation for field joints of piping requiring PWHT,may be buttered ,then subjected to
PWHT,machines while during shop fabrication. The field joint shall be qualified without PWHT.

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Annex D User Feedback Form

SP-1173 – Supplementary specification to API 582 for Welding of Pressure

containing equipment and piping

User Feedback Form

Any user who identifies an inaccuracy, error or ambiguity is requested to notify
the custodian so that appropriate action can be taken. The user is requested to
return this page fully completed, indicating precisely the amendment(s)
recommended.
Name
Organisation
Email Date:

Clause Ref: Brief Description of feedback and technical justification

Material corrosion and Inspection (UEC) CFDH

Custodian of Document Date:

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