SAEP-310

Engineering Procedure SAEP-310

13 January 2008

Piping and Pipeline Repair Piping Standards Committee Members Nasri, Nadhir Ibrahim, Chairman Chairman Dib, Tony Georges, Georges, Vice Chairman Chairman Balhareth, Nasser Nasser Mohammad Bannai, Nabeel Saad Fadley, Gary Lowell Holland, Brad John Khashab, Jaafar M. Lewis, Trevor Trevor Mahmoud, Khalid Ahmed Phan, Howard Cong Rao, Sanyasi Rasheed, Mahmood A. Sharif, Talal Mahmoud Shiha, Saad Mohammed Swar, Ahmad H. (ABQ PLANTS)

Saudi Saudi Aramco Aramc o Desk DeskTop Top Standards Standards Table of Contents 1 2 3 4 5 6 7 8 9

Scope.................... Scope.................................. ........................... .......................... ............... 2 Applicable Documents............... Documents..... ..................... .................... ......... 2 Definition............. Definition............................. ............................... ........................... ............ 5 General Requirements............. Requirements.. ...................... ...................... ........... 5 Excavation and Burial (Buried Pipe).............. Pipe)...... ........ 6 Pipe Defect Removal and Replacement........ Replacement..... ... 7 Repair Methods and Requirements............. Requirements.. ............. .. 8 Repair Applications............. Applications.. .................... ...................... ................ ... 12 Welding on Pipelines and Process Piping for Repairs................... 13 10 Pressure Testing................ Testing..... ..................... ..................... ................ ..... 15 11 Coatings............... Coatings.............................. ............................. ......................... ........... 16 12 Cathodic Protection.............. Protection... ..................... ...................... .............. .. 16 Appendix A – Typical Metallic Repair Repair Sleeve..... Sleeve..... 17

Previous Issue: 29 November 2006 Next Planned Update: 29 November 2011 Revised paragraphs are indicated in the right margin Primary contact: Nasri, Nadhir Ibrahim on 966-3-8734525 Copyright©Saudi Aramco 2008. All rights reserved.

Page 1 of 39

Document Responsibility: Responsibility: Piping Standards Committee Issue Date: 13 January 2008 Next Planned Update: 29 November November 2011

1

2

SAEP-310 Piping and Pipeline Pipeline Repair

Scope 1.1

This SAEP describes the procedures to be followed for the repair of in-plant piping and onshore/offs onshore/offshore hore pipelines, pipelines, as as covered by ASME B31.4, ASME ASME B31.8 and API RP 570.

1.2

The repair method for offshore piping and pipeline selection shall be based on the most economical and the most practical.

1.3

The methods and procedures set forth herein are minimum requirements and are not a release from the responsibility for prudent action that circumstances make advisable.

Appli cable Documents 2.1

Saudi Aramco References Saudi Aramco Engineering Procedures SAEP-306

Assessment of the Remaining Strength of Corroded Pipes

SAEP-311

Installation of Hot Tapped and Stopple Connections

SAEP-321

Performance Qualification Testing and Certification of Saudi Aramco Welders

SAEP-345

Composite Non-Metallic Repair Systems for Pipelines and Pipework

SAEP-1143

Radiographic Examination

Saudi Aramco Engineering Standards SAES-A-004

General Requirements for Pressure Testing

SAES-H-002

Internal and External Coating for Steel Pipeline and Piping

SAES-H-203

Hand-Applied Tape Wrapping of Buried Pipe

SAES-L-150

Pressure Testing of Piping and Pipelines

SAES-L-350

Construction of Plant Piping

SAES-L-410

Design of Pipelines

SAES-L-450

Construction Requirements for Cross Country Pipelines Page 2 of 39

Document Responsibility: Responsibility: Piping Standards Committee Issue Date: 13 January 2008 Next Planned Update: 29 November November 2011

SAEP-310 Piping and Pipeline Pipeline Repair

SAES-W-011

Welding Requirements for On-Plot Piping

SAES-W-012

Welding Requirements for Pipelines

SAES-X-400

Cathodic Protection of Buried Pipelines

Saudi Aramco General Instructions GI-0002.100

Work Permit System

GI-0002.102

Pressure Testing Safely

GI-0002.711

Fire and Safety Watch

GI-0006.012

Isolation, Lockout and Use of Hold Tags

GI-0006.021

Safety Requirements for Abrasive Blast Cleaning

GI-0150.001

Asbestos Regulations

GI-1780.001

Atmosphere-Supplying Atmosphere-Supplyi ng Respirators

Saudi Aramco Standard Drawings AB-036029 AB-03602 9

Non-Pressure Containing Repair Sleeves with Welded Buttstraps

AC-036261 AC-03626 1

Pipeline Corrosion Barrier Patch

AB-036262 AB-03626 2

Pressure Containing Repair Sleeves with Full Penetration Butt Welded Seams

AC-036263 AC-03626 3

Weld Metal Build-Up for the Repair of Pipeline Surface Defects

AE-036265 AE-03626 5

Pipeline Repair Patch for Minimum Wall Thickness Violations

AC-036279 AC-03627 9

Corrugated Weld Repair Sleeve Pipe Size 6" Through 48"

AA-036352 AA-03635 2

Details of Installation, Galvanic Anodes for Road & Camel Pipelines Crossing, Pipeline Repair Locations

AB-036381 AB-03638 1

Cathodic Protection Thermit Welding of Cables to Buried Pipelines Pipelines

AB-036478 AB-03647 8

Magnesium Anode Installation at Pipeline Repair Locations, Locations, Layout, Sections Sections and Details Details

AB-036526 AB-03652 6

Weld over Sleeve for Repair of Leaking Sleeves on 30" & 31" O.D. Pipe

AC-036655 AC-03665 5

Tie Rod Arrangement for Weld+Ends Coupling

Page 3 of 39

Document Responsibility: Piping Standards Committee Issue Date: 13 January 2008 Next Planned Update: 29 November 2011

SAEP-310 Piping and Pipeline Repair

AC-036660

Road Crossing for P/L Sht. 1, 2, 3, 4

AB-036880

Sleeved Crossing for Restrained Pipelines

AE-036833

Detail of Pipe Repair Plug

AB-036899

Shoring Trenches

Saudi Aramco Manuals Saudi Aramco Construction Safety Manual Saudi Aramco Crane Safety Handbook 2.2

Industry Codes and Standards American Society of Mechanical Engineers ASME B31.3

Process Piping

ASME B31.4

Liquid Transportation Systems for Hydrocarbons, Liquid Petroleum Gas, Anhydrous Ammonia and Alcohols

ASME B31.8

Gas Transmission and Distribution Piping Systems

ASME B31G

Manual for Determining the Remaining Strength of Corroded Pipelines

American Petroleum Institute API STD 1104

Standard for Welding Pipelines and Related Facilities

API RP 570

Piping Inspection Code: Inspection, Repair and Re-rating of In Service Piping System

API RP 579

Fitness-for-Service

National Association of Corrosion Engineers NACE RP0177

Mitigation of Alternating Current and Lightning Effects on Metallic Structures and Corrosion Control Systems (Item 53039)

American Gas Association Gas Purging Principles and Practices

Page 4 of 39


3


Definition Pyrphoric Material: Self igniting material (iron sulfide). In the absence of oxygen, sulfur compounds or hydrogen sulfide in hydrocarbon stream react with steel to form iron sulfide.

4

General Requi rements 4.1

Any repair methods that are not addressed in this procedure shall be reviewed and approved by the Chairman of the Piping Standards Committee.

4.2

Prior to commencing repair activities, defect assessment for metal loss shall be conducted in accordance with SAEP-306 for pipelines, and in accordance to API RP 570 in-plant piping design to ASME B31.3.

4.3

Engineering calculations should be performed to determine the permissible pipe movement and the required support system during any repair.

4.4

Prior commencing any repair work, a written procedure shall be developed. The procedure shall be approved by all parties involved in the repair activities.

4.5

4.4.1

The procedure shall comply with GI-0002.100, "Work Permit System", GI-1780.001,"Atmosphere-Supplying Respirators", GI-0002.102, "Pressure Testing Safely", GI-0006.012, "Isolation, Lockout, and Use of Hold Tags", GI-0002.711 "Fire and Safety Watch".

4.4.2

The procedure shall include detailed requirements for safe working conditions. Repair shall be performed under qualified supervision by trained personnel aware of and familiar with hazards to personnel, public and environment. Appendix B, protection against electric shock from induced voltage and underground cable may be used as minimum requirements.

4.4.3

The procedure shall detail the safety measures associated with all mechanized repair equipment.

4.4.4

The procedure shall include all required data such as pipe diameter, wall thickness, grade, etc.

4.4.5

All repairs shall be tracked in accordance with Management of Change Procedure of the operating organization.

In case of small leak (weeping), the pipe pressure shall be lowered to 80% of the current operating pressure if the pipe is operating at more than 40% SMYS. Once the pressure level has been controlled, the pipe defect shall be examined, and repaired. Page 5 of 39


4.6


Pressure reduction, when the pipeline defects are not acceptable perSAEP-306 or API RP 579 for pipelines and in-plant piping respectively, shall be con sidered if the pipe is operating at more than 40% SMYS. Commentary Note: Pressure reduction provides a minimum level of assurance that the defect or anomaly will not fail during the course of its examinations and repair.

5

Excavation and Burial (Buried Pipe) 5.1

Prior to the start of excavation, the Operation Department shall identify all underground piping and cables crossing in the vicinity of the excavation, and notify the appropriate authorities to assist in the supervision of the excavation.

5.2

The buried pipe shall be located by electronic locating devices, manual probing, or test excavations. The pipe locations shall be marked with brightly colored flags. If crawler dozers are used, mark and flag all lines within 60 m (200 ft) of the repair site. Commentary Note: Crawler dozers are used to remove sand dune in case of transportation pipelines.

5.3

The buried pipe depth shall be identified and marked. Manual excavation is mandatory when the pipelines depth of cover reach 1220 mm (4 ft) or the excavation is 914 mm (3 ft) adjacent to the buried pipe.

5.4

The underground sections of pipe requiring repairs shall be uncovered, while under pressure, in sections up to 15.24 m (50 ft) long and separated by buried sections of equal length. There is no limitation on the total length of pipeline that may be uncovered in alternating 15.24 m (50 ft) sections. Approval of the Chairman of the Piping Standards Committee is required when exposing more than 15.24 m (50 ft) of the buried pipe section.

5.5

The working clearance around the buried pipe shall be adequate for work being performed.

5.6

For excavations over 1219 mm (4 ft) deep, the sides of the pits and trenches should be sloped back to the natural repose of the soil to avoid a cave-in. Sides which cannot be sloped to natural repose shall be shored according to Standard Drawing AB-036899.

5.7

Backfilling shall be according to SAES-L-450 for pipelines and SAES-L-350 for in-plant.

Page 6 of 39


6


Pipe Defect Removal and Replacement 6.1

Pipeline sections with cracks, rupture or with defects that cannot be repaired shall be removed or replaced. The repair of cracks, other than their complete removal, shall be reviewed and approved Consulting Services Department.

6.2

The minimum length of any replacement section shall not be less than two times of the pipe diameter but not shorter than 305 mm (12"). The new section shall not be installed closer than 152.5 mm (6") to an existing weld. Commentary Note: Minimum length of the new section is required to ensure the proper fit-up and high integrity welds. Full radiographic examination is required in some cases.

6.3

6.4

Prior commencing any replacement, pipe isolation and displacing or purging of hydrocarbon procedure shall be developed according to paragraph 4.4. The procedure shall ensure safe, non-combustible atmosphere in the pipe and in the vicinity of the work area. 6.3.1

The pipe shall be isolated by blind flanges, blanks or two isolation valves. When using isolation valves, verification before and during the work is required to ensure that the valves do not leak. Bleed connection shall be installed between the two isolation valves to ensure no pressure build up.

6.3.2

Testing of the atmosphere in the pipe and in the vicinity of the work area shall be conducted before the work is started and at intervals as the work progresses.

Pipe cut should be made with mechanical cutters. Torch cut can be performed on pipe only if the pipe is free from combustible material. An engineering evaluation shall be conducted before performing pipe cut according to paragraph 4.3.

6.5

Hydrocarbon spillage is not permitted in hot work area. In case of cross country pipelines, oil saturated sand shall be removed or completely covered with clean sand. Pyrophoric material shall be kept wet to prevent auto-ignition. Sludge in pipelines suspected of containing iron sulfide shall be drained to an isolated area at least 32 meters away from any other flammable substance.

Page 7 of 39


6.6

7


The open hydrocarbon shall be isolated, when possible, by a plug prior conducting any hot work. Vents/drains shall be installed upstream the plug to prevent pressure build up and drain standing liquid. For the type of plugs see Appendix C. 6.6.1

When installing a plug is not practical in an open hydrocarbon pipe, the isolated section shall not include any combustible atmosphere.

6.6.2

The vent/drains shall be sized to permit draining/venting the line section in one hour with atmospheric pressure. Table A-2 of appendix A can be used as a guideline to size the drain line.

6.7

The new replacement section shall meet the requirements of SAES-L-410 and SAES-L-450 for pipeline and SAES-L-310 and SAES-L-350 for in-plant piping.

6.8

The welding procedure shall be according to paragraph 9.

6.9

The use of repair couplings such as Weld+Ends is permitted only for cross country pipeline. They should be used only where it is not practical to perform the girth welds. The rating of the repair couplings shall meet the design condition of the pipeline. 6.9.1

The tie rod arrangement of Weld+Ends couplings, when required, shall be installed as per Standard Drawing AC-036655.

6.9.2

The Weld+Ends couplings shall be installed in accordance with Appendix-D of this procedure.

6.9.3

For FBE or cement line pipe, specially designed and fabricated couplings shall be used.

Repair Methods and Requi rements 7.1

Grinding is permitted to repair stress concentrating effect such as a gouge, scratch, arch burns, or grooves. The grinding contour shall be smooth. 7.1.1

The limit of the metal removal shall be according to SAEP-306 for metal loss criteria. The maximum metal loss shall not exceed 40% of the nominal wall thickness.

7.1.2

The removal of the defect shall be verified by conducting NDE such as dye penetrant or magnetic particle inspection.

7.1.3

Surface cracks can be removed by grinding following the approval of the Consulting Services Department. The crack shall be mapped to determine the extent of the defect. Page 8 of 39


7.2

7.3


Weld metal build up may be used only for pipeline defects with metal loss. The metal loss can be caused by external corrosion or gouges, groove and excessive grinding. 7.2.1

The pipeline metal loss defect assessment shall be according to paragraph 4.3. Welding on pressurized pipeline shall be according to paragraph 9.6.

7.2.2

The maximum length or width of any individual repair area shall not exceed 102 mm (4"). The repair area shall be separated by at least 102 mm (4") from any other repair area.

7.2.3

Weld metal build up shall be according to Standard DrawingAC-036263.

Patches and half sleeve repair techniques are allowed only on pipe with specified minimum yield strength (SMYS) of 275,800 kPa (40,000 psi) or less. Commentary Note: Research and test have shown that the longitudinal fillet weld to pipe is a potential weak point.

7.4

7.3.1

The patches shall be according to standard drawing AC-036261.

7.3.2

This method shall not be used for internal corrosion defects.

Pipeline Repair Sleeves 7.4.1

Type A repair sleeve (Pressure Containing Sleeve, Figure 1, Appendix A) may be used for leaks or for pipe with internal corrosion defects. 7.4.1.1

The design strength (SMYS) of the repair sleeve shall be the same or greater than the pipe.

7.4.1.2

For leaking pipe, a steel or wooden plug shall be installed prior installing the repair sleeve. The repair sleeve shall not be welded until the leak is completely stopped and no combustible fumes are presents in the annulus.

7.4.1.3

The minimum length of type A sleeve shall not be less than 102 mm (4"). The sleeve shall extend a minimum of 50.8 mm (2") on either side of the defect.

7.4.1.4

Multiple sleeves may be used for extended defects. When the length of the sleeve or sleeves exceeds 4 pipe diameters, formal analysis is required according to paragraph 4.3 to avoid any sagging of the pipe. Page 9 of 39


7.4.2


7.4.1.5

The repair sleeve shall be cut to provide close fit-up dimensions and installation of the sleeve shall be according to Standard Drawing AB-036262.

7.4.1.6

The welding of the sleeves shall be according to paragraph 9.

Type B repair sleeve (Butt Strap Non Pressure Containing Sleeve Figure 2, Appendix A) shall be used as corrosion barriers or to provide added reinforcement to the pipe metal loss due to external corrosion or excessive grinding. It also can be used for dents violating the applicable code. Commentary Note: Type B repair sleeve shall not be used to contain internal pressure because the lap-type joint in the buttstrap is not as flexible as the buttwelded seam to absorb the required strains induced while containing the internal pipeline pressure.

7.4.3

7.4.4

7.4.2.1

Type B repair sleeve shall be in according to Standard Drawing AB-036029.

7.4.2.2

Hardenable fillers such as epoxy or polyester shall be used to fill the gaps between the sleeve and the pipe in all defect locations.

7.4.2.3

The circumferential welds to the carrier pipe are not mandatory. However, the annulus shall be sealed from dirt and debris. The sealant compound shall be approved by the Chairman of the Piping Standards Committee.

Type C repair sleeve (Corrugated Weld Repair Sleeves, Figure 3, Appendix A) may be used for repair of leaking girth welds. 7.4.3.1

The repair sleeve shall be vented through the ½ vent to a safe location. Refer to paragraphs 7.4.1.2 and 7.4.1.3.

7.4.3.2

The repair sleeve shall be according to Standard Drawing AC-036279.

Type F repair sleeve (Weld over Sleeves, Figure 4, Appendix A) may be used for Type C repair sleeves suffering leaks. It is specially designed according to Standard Drawing AB-036526. Type A repair sleeve, when experience cracking at the toes of the fillet welds, may be repaired by installing sleeve-on-sleeve. The configuration shall be approved by the Engineering Division of the Operating Organization. Page 10 of 39


7.4.5


Epoxy filled repair sleeve may be used instead of Type B repair sleeve. Epoxy fill repair sleeves do not require welding to the carrier pipe. Installer shall be certified by the repair sleeve manufactures. Commentary Note: The repair comprises two oversized steel half-shells that are joined to encircle the damaged area, leaving an annular gap. The annulus is sealed at each end of the sleeve using a simply applied fast-setting material, and then filled at very low pressure with a stiff epoxy-based compound.

7.4.6

7.4.7

Bolt on Clamps such as PLIDCO Split Sleeves or PLIDCO SMITH+CLAMP may be used on blowouts or punctures which cannot be readily sealed by plugs or patches. 7.4.6.1

Bolt on Clamps should not be used instead of Type A repair sleeve unless it is economically justified.

7.4.6.2

Bolt on Clamps shall not be used for pipe with general corrosion of 70% wall loss and more.

7.4.6.3

Bolt on Clamps packing material shall be compatible with the service fluid.

7.4.6.4

Permanent Bolt on Clamps may be welded. The maximum interpass temperature shall not exceed the maximum design temperature for packing material.

7.4.6.5

Bolt on Clamps, if approved by CSD, are acceptable for use up to their rated pressure and temperature.

7.4.6.6

All coatings rust and scale shall be removed from the pipe surface where the Bolt on Clamps circumferential seals will contact the pipe.

7.4.6.7

The Bolt on Clamps seals shall not be installed in surface irregularities greater than ±1/32".

Bolt on Clamp with injection sealant may be used as a temporary repair for leaking flanges or pipe to avoid plant shutdown. 7.4.7.1

Formal analysis shall be conducted to evaluate the additional clamp weight on the piping system.

7.4.7.2

The injection sealant shall be compatible with the service fluid and shall not affect the downstream components. Page 11 of 39


7.4.8

8


7.4.7.3

The design and the rating of the clamp shall be reviewed and approved by the Engineering Division of the operating organization.

7.4.7.4

The Clamp shall be monitored periodically for leaks.

Saudi Aramco approved Non-metallic repair sleeves may be used for external metal loss and mechanical defects such as dents. 7.4.8.1

Non-metallic repair sleeve installation procedure shall be review and approved by the Chairman of the Piping Standards Committee. Workers shall be certified by the non-metallic repair sleeve manufacturer.

7.4.8.2

Non-metallic repair sleeve shall be used on a temporary basis for internal metal loss with inactive corrosion or known corrosion rate provided that it meets all the requirements of the SAEP-345.

7.5

Bolted patch clamp (bolted clamp with elastomeric material) are permitted only in low pressure utility piping.

7.6

Epoxy patch such as Belzona repair batch is permitted only to restore the original external profile. It shall not be used as repair by itself.

7.7

Pipe defects may be removed by hot-taping. For hot tap procedure refer to SAEP-311.

Repair Appli cations 8.1

8.2

All in-plant piping repairs are temporary until replacement can be carried out in the next available shutdown window. 8.1.1

The selection of repair method for in-plant piping shall take into consideration not only the design condition, but other perceivable conditions such as upset condition and emergency.

8.1.2

Repair methods consist of non-metallic material such as elastomeric seals are not permitted in piping system intended to retain their integrity under external fire loading.

Plant piping and pipelines repair methods should be according to Table A-1, Appendix A. Selection of the repair method should be evaluated on the economics and the practicality of the repair methods.

Page 12 of 39


9


8.3

Pipe defects that are not addressed in Table A-1 should be reviewed by the engineering division to select proper corrective action.

8.4

Pipe with an unacceptable Hydrogen Induced Cracking (HIC) defect should be replaced. If the replacement of hydrogen damaged pipe is not feasible, then the requirements of this section shall be followed. 8.4.1

Expose the full joint of pipe as well as a portion of the adjacent joint on each side and determine the extent of the defect indications. Continue exposing as much pipe as necessary until the extent of the area with defect indications is determined.

8.4.2

Determine the size and depth of the defects with ultrasonic testing. Ultrasonic indications may mean any of several things, including ongoing cracking, corrosion damage, the presence of pre-existing and rather harmless laminations, or simply elongated inclusions in the steel. When ultrasonic or radiographic inspection reveals crack-like defects, further examination is required to determine the nature of the defects.

8.4.3

The HIC decision tree, (Appendix E), assesses the severity of the hydrogen damage and provides recommendation for corrective action. Assessment may require removal by Hot-Tapping of coupons for metallurgical analysis. Hydrotesting, monitoring, increased inhibition, sleeving or replacement of cracked areas may be required. No corrective action shall be taken without the concurrence of the Coordinator, Materials Engineering and Corrosion Control Division, Consulting Services Department.

Welding on Pipelines and Process Piping for Repairs 9.1

Welders and welding procedures shall be qualified according to SAES-W-011, Welding Requirements for On-Plot Piping and SAES-W-012, Welding Requirements for Pipelines.

9.2

All welding of patches, sleeves, and weld build-up shall be in accordance with applicable Saudi Aramco Welding Procedure Specification.

9.3

Welding longitudinally to the axis of the pipeline is not permitted except as approved by this procedure.

9.4

For carbon steels with minimum specified yield stresses greater than 60 ksi, the Consulting Services Department shall be contacted for welding procedure approval.

9.5

Pipeline retaining residual magnetism above 20 Oe (Oersteds) shall be Page 13 of 39



demagnetized before conducting any welding. Commentary Note: Pipelines often retain residual magnetism following a cleaning run by a Magnetic Cleaning scraper, or an inspection by MagneScan or other magnetic Flux leakage tool.

9.6

Welding on pressurized pipeline. 9.6.1

The pressure in the pipe during welding shall not exceed that calculated by the following formula: Pmax =

2S(t − 0.10)F OD

(1)

Where: Pmax =

Maximum operating pressure of the pipeline during welding, psig

S

=

Specified minimum yield strength of the pipe, psi

t

=

Minimum measured wall thickness of the pipe at the weld area, inches.

F

=

0.72 (Design factor of the pipeline).

OD

=

Outside diameter of the pipe, inches.

Commentary Notes: 1.

The minus 0.10 inch wall thickness takes into account the molten and heat affected portion of the base metal which does not contribute to pressure containment.

2.

For in-plant piping designed to ASME B31.3, replace S and F in the formula with the allowable stress in Table A-1 of ASME B31.3.

To ensure the wall thickness is thoroughly measured, a continuous UT scan shall be conducted around the circumference of the pipe weld areas. 9.6.2

To further minimize the possibility of "burn through", no welding shall be allowed in areas with a wall thickness below 5 mm or below the pressure design thickness of the pipe. Welding can be carried out on pipe containing hydrocarbon, only when there has been no combustible mixture.

9.6.3

In cases where a pipeline has been cut or ingress of air has otherwise been allowed, the air must be removed from the pipeline before welding can be performed. One method of removing the air is by putting the line Page 14 of 39



in service with an adequate flow rate to ensure that the air is displaced from the pipeline. Once this has been achieved, welding can proceed with or without flow. 9.7

10

Non-Destructive Examination 9.7.1

All welds made for the installation of pipe sleeving or patching for pressure containment (Type A and PLIDCO Split Sleeve), and for weld metal build-up, shall be inspected by M. T. or P.T.

9.7.2

Welds within 19 mm or 3 times the wall thickness of the pipe from an existing girth weld shall be inspected by MT or PT.

9.7.3

Additional inspection may be requested as required by the assigned the responsible Inspection Organization.

9.7.4

Thickness Measurement using ultrasonic thickness shall be taken on all pipe areas where welding is to be done.

9.7.5

The defect removal shall be verified be the same methods that detected it originally.

Pressure Testi ng 10.1

When the new pipe replacement section is to be hydrotested prior installation, the hydrotest shall be according to SAES-A-004 and SAES-L-150.

10.2

When the piping system with replacement section is to be hydrotested, the test shall be in full compliance with SAES-A-004 and SAES-L-150.

10.3

When the hydrotest is not practical, full compliance of SAES-A-004 shall be adhered to along with the following requirements: 1)

Verification of the pipe mechanical prosperities through the mill certificate.

2)

Visually inspect all mill applied welds of the spiral or longitudinally welded joint(s) of new pipe prior to installation in the pipeline.

3)

Radiograph or ultrasonically check all suspect areas of the manufacturers' welds found to be defective by visual inspection.

4)

Repair all manufacturers weld defects and radiograph repairs to assure defects are removed.

5)

Visually inspect the pipe ends for proper bevel and evidence of no laminations. Repair as required.

Page 15 of 39


11

12


6)

Radiograph all butt welds required to install the new pipeline section and repair defects as required.

7)

Provide an approve NDE In-Lieu-of Pressure Test.

Coatings 11.1

Refer to SAES-H-002 and SAES-H-203 for selection and application of internal and external coating systems and tape wrapping for pipelines.

11.2

Refer to GI-0006.021, "Safety Requirements for Abrasive Blast Cleaning", when preparing pipe surfaces for coating using abrasive blast cleaning.

Cathodi c Protection 12.1

When repairs are made due to external corrosion, the proponent cathodic protection unit within the operating organization shall determine when and where supplemental "Hot Spot" cathodic protection will be used.

12.2

A minimum of two (2) magnesium anodes shall be used for supplemental cathodic protection. The anodes shall be installed on alternate sides of the pipeline. The placement shall be such that one anode is installed at each end of the repair area.

12.3

Anode requirements and installation details are found in Standard Drawings AB-036478, "Magnesium Anode Installation at Pipeline Repair Locations; Layout, Sections and Details", and AA-036352, "Details of Installation of Galvanic Anodes for Road and Camel Crossing and Pipeline Repair Locations".

12.4

Anode connections to the pipeline shall be Thermit welded as per Standard Drawing AB-036381, "Cathodic Protection; Thermit Welding of Cables to Buried Pipe lines".

29 November 2006 13 January 2008

Revision Summary Major revision. Editorial revision.

Page 16 of 39



Appendi x A – Typical Metallic Repair Sleeve

Figure 1 – Type A Sleeve, Pressure Containing Full Encirclement Sleeve

Figure 2 – Type B Sleeve, Butt Strap Non-Pressure Containing Sleeve

Page 17 of 39



Figure 3 – Type C Sleeve, Corrugated Weld Repair Sleeve

Figure 4 – Type F Sleeve, Weld over Sleeve

Page 18 of 39



Appendi x A-1: Repair Method Selecti on Table 1

Table A-1: Saudi Aramco Repair Applications g n i d n i r G 2 n Plant Piping o i e t On shore a p i c i l Pipeline P p p Off Shore A Pipeline Small defect t c e <0.5D e i z f e S Large Defect D > 0.5D Leaks

External n s Corrosion o t i s c Pitting Lake < o e f r 0.85t r e o D Pitting Lake C > 0.85t Internal corrosion a Dents c e i g n a a m Dents/ Gouge h a c e D l M Wrinkle Bend 3

s k c a r C

r e h t s O

Shallow Cracks4 < 0.4t Deep Cracks > 0.4t Blisters Girth Weld Defects

s f l d d e e l e h d a i a v l t l d h e e e u l t c e l W m b e a r o S W P

A e e v e p l y e T S

B e e v e p l y e T S

r e y d i x e a v e o l l p e p i e l F R S

n c s n s i o n l i o p p l e h t t m a v t m a i c o t l e a l w j e N e l e o l B C C I n m s

g t i n o p H a T

Yes

No

Yes

Yes

No

No

Yes

Yes

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

Yes

Yes

Yes

No

No

No

No

Yes

Yes

No

Yes

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

Yes

Yes

Yes

Yes

No

Yes

No

No

No

No

Yes

No

No

Yes

Yes

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

Yes

Yes

No

Yes

Yes

Yes

Yes

Yes

Yes

No

Yes

No

No

No

No

Yes

No

No

Yes

No

No

Yes

No

No

No

Yes

No

No

Yes

No

No

No

No

No

No

Yes

Yes

Yes

Yes

No

Yes

No

No

No

No

Yes

Yes

Yes

Yes

No

Yes

No

No

No

No

Yes

Yes

Yes

Yes

No

No

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

Yes

Yes

No

No

No

Yes

No

No

Yes

No

No

Yes

No

No

No

Yes

No

No

Yes

No

NO

No

Yes

Yes

No

Yes

No

No

No

No

Yes

No

1

This table shall not be used without addressing the repair techniques limitations in paragraphs 7 and 8 of the SAEP-310.

2

All plant piping repair are temporary maximum until the next plan shutdown.

3

All crack defects require a qualified corrosion /metallurgy engineer to investigate the cause and review the corrective action or repair procedure

4

Shallow cracks shall be grinding before applying any repair technique.

Notes: 1.

Assigned inspection unit shall review the repair procedure, add any quality requirements, attend all hold points specified by inspector and approve repair work when completed.

2.

For dents and external metal loss, the pipe original external profile shall be restored by applying Hardenable fillers.

Page 19 of 39



Table A-2: Vents/Drain Sizes Size (in)

Ap pr ox . Capacit y (barrel/hr)

1

15

-

30

2

65

-

130

3

145

-

300

4

260

-

500

6

600

-

2000

8

1000 -

4000

EXAMPLE: Consider 609.6 m of 6 in flow line. Contents are approximately 2000/1000 x 6² = 72 barrels. A 2 in drain should be provided.

Page 20 of 39



Appendi x B – Protecti on against Electri c Shock from Induced Voltage and Underground Cables This Appendix contains mandatory practices which safeguard personnel against the hazards of electric shock during the installation, operation, or maintenance of above ground and buried pipelines routed near overhead, high-voltage power lines. These practices apply to pipelines routed within 152.4 m of any energized 115-kV and 230-kV power lines, and also to 69-kV lines if parallel lengths are 1.6 km or greater. Safety precautions to prevent shock due to induced voltage, as stated in this Appendix, for pipelines routed in the vicinity of lower voltage power lines, i.e., (4.16-kV and 13.8-kV), are normally not required. All work on pipelines shall stop during lightning and thunderstorms. The following conditions are not exempt from the mandatory practices of this section: a)

Line not cathodically protected.

b)

Line section isolated by insulation flanges.

c)

Cathodic protection rectifiers and generators shutdown. B-1

Buried Pipelines

B-1.1 No special precautions need to be taken during local excavations exposing less than 15.24 m of pipeline except when cutting into an existing line and/or removing a section of the pipeline, then Paragraph B-2.4 shall be observed. Paragraph 5.4 limits the length of pressurized piping, which can be exposed in a single excavation to 15.24 m. B-1.2 When work on existing buried pipelines requires the exposing of 15.24 m or more of the line, it shall be regarded as an above ground pipeline. Appropriate precautions, taken in accordance with Section B -2, shall be implemented. B-1.3 Prior to the start of excavation, the Operations Department shall identify all underground cables crossing in the vicinity of the pipeline excavation, and notify the appropriate authorities, i.e., (Power Distribution Dispatchers, SEC), to assist in the supervision of the excavation. A minimum spacing of 914 mm is required between the bottom of the pipeline and the top of the cable duct bank. Therefore, extreme care must be taken when excavating below the pipe. Normally, buried cable markers indicate the location of the cables, but they may have been inadvertently removed or never installed. When cable markers are not Page 21 of 39



shown, a safe maximum distance of 610 mm from the bottom of the pipe should not be exceeded. B-2

Above Ground Pipelines

B-2.1 All work on exposed pipelines shall be carried out from a wire mat that is electrically bonded to the pipeline at each end of the repair area. B-2.2 If the ground mat can not be bonded to the pipeline, two (2) carbon steel, 13 mm diameter studs shall be welded at each end of the pipeline repair area to provide the required grounding connections. The areas where the studs are to be welded shall be cleaned prior to welding as per SAES-W012. If studs are removed, the weld areas shall be ground flush with the pipe and a Liquid Penetrant or Magnetic Particle Test (PT or MT) inspection shall be made to insure no harmful defects remain. B-2.3 Rubber gloves shall be worn for all operations on the line until the mat is properly positioned and bonded to the line. Similarly, rubber gloves shall be worn when removing the bonds. B-2.4 When the repair of a pipeline requires cutting an existing line or unbolting flanged connections, a flexible bonding cable, no less than No. 2 AWG, shall be attached across the section of line to be separated prior to cutting or unbolting. Bonding cables may be thermit welded to the pipe as per Standard Drawing AB-036381. The cable shall remain attached until after the line is repaired. After the removal of the of the bonding cable, the attachment areas shall be ground flush with the pipe surface and a Liquid Penetrant or Magnetic Particle Test (PT or MT) inspection shall be made to insure no harmful defects remain. Grounding mats shall not be used as a bonding cable. The cable shall be installed so that it is fully protected from movement of workers and equipment. Refer to NACE RP0177 Item No. 53039. B-2.5 All electric arc welding operations shall be carried out with the welding machine bonded to the ground mat and pipeline, with the welder working on the ground mat. B-2.6 When working on lines supported on steel structures, such as at road crossings, etc., ground mats are not necessary. However, the lines should be bonded to the steel structure to ensure a proper ground and the requirements of Paragraph B-2.4 implemented.

Page 22 of 39


B-3


Valves on Above Ground and Buried Pipelines

B-3.1 Unless noted otherwise on the Work Permit, no special precautions need to be taken when operating or maintaining valves located below ground and form part of a buried pipeline. B-3.2 Where metal platforms or temporary scaffolds are installed to provide access to valves on an above ground pipeline, the platforms shall be electrically bonded to the pipeline on each side of the valve before work starts. The requirements of Paragraph B-2.4 shall be observed when making and removing the bonding connection. B-3.3 The electrical bond shall consist of a No. 2 AWG flexible conductor, such as a welding cable, connected to the platforms at one end and terminated at the free end by a 50 amp rated test clip with insulator. Access to the platform shall be by a 36 inch square rubber mat.

Page 23 of 39



Appendix C – Types of Isol ation Plugs Saudi Aramco stocks three types of plugs: Balloons, Mud Plugs and Mechanical Plugs. However, there are many other plugs available in the market which could be used if they were proven to be equivalent or better than the types described in this Appendix. Any plug, other than a mud plug, shall be removed before the line is closed. Mud plugs normally remain in the line but may be removed, if circumstances dictate or must be removed if they contain Gypsum Plaster see C-2.5 below. C-1

Balloons (Stopper)

The inflatable balloons have polyester cover and gum rubber bladder, bag type. They are also fitted with inflating valve nipple and hose clamp. Balloons are available in Saudi Aramco material system for nominal pipe sizes 2 through 60 inch. C-1.1 The canvas covers of the balloons are at best only moderately fire resistant. Additional precautions that make their use safer include mud dams and inert gas purges. C-1.2 Balloons shall be inflated carefully so as to ensure that the relatively low allowable pressures are not exceeded. A suitably graduated pressure gauge shall be utilized during inflation. For sizes 22 inch and larger, the pressure gauge shall be graduated in inches of water. Table C-1 gives the maximum inflation pressure of the balloon. C-1.3 The balloon can withstand only a small differential pressure (up to 10 psig for small diameters and only up to 1 psig for large diameters), and therefore, the job must be planned to have zero line pressure. C-2

Mud Plugs

Mud plugs are a mixture of special types of mud with water. After preparation in the field, the mud is erected to provide the required seal. Table C-2 shows a comparison between the balloon plug and mud plug. C-2.1 The mud plug is composed of the following components: Bentonite (clay), 23 kg sack, Material no. 1000021551 Cottonseed hull, 23 kg sack, Material no. 1000021603 Expanded Vermiculite, 15 kg sack, Material no. 1000248228 Gypsum Plaster, 45 kg sack, Material no. 100188115

Page 24 of 39



C-2.2 In building a mud plug, Bentonite should be mixed with only sufficient water to make a very stiff paste, refer to Table B-3 for guidelines of the Bentonite and water quantities. C-2.3 For lines larger than 305 mm diameter, light-weight material such as expanded Vermiculite can be added to reduce the tendency of the plug to slump. Mix the Bentonite and Vermiculite dry, in a mortar box. Add only enough water to make a very stiff paste as per guidelines of Table C-3. The Vermiculite will shrink when handled, so try to avoid excessive mixing. C-2.4 Avoid the use of heavy materials in the mud mixture, such as Baryte (Baroid). They are not sticky and can only make it more difficult to build the plug up to the top of the pipe. C-2.5 If Gypsum plaster is used to increase the strength of the plug, it must be removed prior to closing the line. C-2.6 Structural support for starting a mud plug can be provided by a balloon. Effectiveness of the balloon can be increased by running a rope through the end ring to hold the balloon while the mud is forced against it. A balloon should not be used unless provisions are made for removing it after closing the line. C-2.7 In very large lines, a dam can be started with full sacks of Bentonite or Baryte. However, the sacks must be removed after welding is completed. As an added precaution, it may be advisable to use two plugs separated by a purged section of line. C-3

Mechanical Plugs

These are proprietary plugs that can withstand higher pressure than balloons or mud plugs, therefore, they create a much better seal for use in welding flanges or valves onto the open ends of operating lines. Saudi Aramco stocks mechanical plugs (steel/rubber) for nominal pipe sizes 3 through 12 inch of the wing nut type. Larger sizes may be obtained on a direct requisition form. C-3.1 Additional safety precautions for mechanical plugs can include: venting, use of mud plugs for added sealant, inert gas purges, and water seals.

Page 25 of 39



Table C-1: Maximum Inflation and P/L Pressure for Balloons of Size 2-60" Nominal Size

Maximum Inflation Kpa (in)

Psig (in)

Water

2, 3, 4, 6

03

15

413

8

83

12

330

10

69

10

275

12

55

8

220

14

48

7

193

16

41

6

165

18

38

5.5

151

20

34

5

138

22

28

4

110

Table C-2: Comparison between Balloon and Mud Plug

Location from weld

Balloon It has to be far from end of line. Balloon could rupture from heat or inadvertent puncture if close to end of line. (D)

Installation

Easier to install

Sealing pressure

Between 1 and 10 psig

Removal

Balloons require special hot taps for insertion and removal except when they are used to weld flanges or valves to the open end of the line.

Mud Plug

Closer to end of line (A)

For large lines, mud plugs are difficult to erect. It needs careful and skillful erection Mud shrinks as it dries. Plugs that are too wet may slump and fail. For these last two reasons, cutting and welding work must be completed as soon as possible after the plug is completed. (D) Cannot be estimated, 0 psig must be assumed. (D) Mud plugs can be left in the line after welding. They can be washed away by the line fluid. (A)

Note: (A) is advantage (D) is disadvantage

Page 26 of 39



Table C-3: Composition of Mud Plugs Nominal Size

Benton ite

Vermicul ite

Water

(in)

(sacks)

(sacks)

(m )

(ft. )

(U.S. gal)

6

1

-

0.03

1

7.5

10

2

-

0.06

2

15

12

3

-

0.08

3

2.5

16

3

2

0.08

3

22.5

20

6

4

0.17

6

45

24

9

5

0.25

9

67.5

30

14

8

0.40

14

105

36

22

13

0.62

22

164.5

40

28

17

0.80

28

209.5

42

33

20

0.93

33

247

48

50

30

0.93

50

374

3

3

Page 27 of 39



Appendix D – PLIDCO Weld +Ends Coupli ngs This Appendix supplements the PLIDCO manufacturer manual which must be the main reference for a successful installation. This Appendix describes the uses, limitations, and installation of PLIDCO Weld+Ends couplings for the purpose of making quick, safe unions on onshore and offshore pipelines, underwater risers, and process piping. D-1

General

D-1.1 PLIDCO Weld+Ends are specialized couplings, used where it is difficult to make quick and safe pipe unions by any other means. They may be used in the repair of onshore or offshore hydrocarbon pipelines, water, steam, or chemical process lines, and underwater risers. PLIDCO Weld+Ends can be welded to the pipe ends or they can be left with clamping and thrust screws tightened, depending on the field situation and product conditions. D-1.2 Standard PLIDCO Weld+Ends have single rows of clamping screw located on the circumference of each end of the coupling. D-1.3 Special PLIDCO Weld+Ends have double rows of clamping screws located on the circumference of each end of the coupling. They are designed specially for excessive end pulling loads, and are restricted (color coded white) by Saudi Aramco for submarine pipeline repair only. D-1.4 In general, the Weld+Ends shall be welded directly to the pipe ends after installation, and by this they are considered anchored and their pressure rating should be the Welded Maximum Allowable Operating Pressure D-1.5 If the Weld+Ends cannot be welded, they are considered not anchored and their pressure rating should be the UnWelded Maximum Allowable Operating Pressure. D-1.6 Clamp+Rings are special PLIDCO Weld+Ends and useful in situations where end pulling loads exceed the coupling's "UnWelded Maximum Allowable Operating Pressure (MAOP)" Rating and conditions do not allow for welding on the line, e.g., underwater pipeline repairs. D-2

Packing (Sealant) Material

To ensure a safe, leak-free seal, it is vitally important that the proper packing material is chosen. This included pressure rating, temperature limitation and product compatibility. This is especially important if the coupling will not be welded and the packing will be the only means to seal the product. Page 28 of 39



D-2.1 Saudi Aramco is mainly using Silicon, Viton, or Buna-N as packing. Silicon is being mostly specified because it is o f lower cost than Viton. D-2.2 Viton shall be used for crude, gas, and hydrocarbon lines if the coupling will not be welded. D-2.3 Viton GF or Aflas should be used for products with amine corrosion inhibitor if the coupling will not be welded. D-2.4 Silicon or Buna-N should be used for water service. D-2.5 If the packing is not compatible with the product, it could still be used subject that coupling shall be completely welded to the line as soon as possible. There shall be no delay between the start and completion of welding. D-2.6 For LPG service and H2S service, the coupling shall be completely welded to the line as soon as possible. There shall be no delay between the start and completion of welding. D-2.7 The manufacturer limits the operating temperature range for:

D-3

i)

Silicone packing at -54 to 232°C.

ii)

Viton packing at -26 to 121°C.

iii)

Buna-N packing, at -29 to 107°C.

Shelf Life

D-3.1 Buna-N has a short shelf life of 2 to 5 years whereas Viton and silicone packing shelf lives of up to twenty (20) years depending on storage condition. Follow the manufacturer recommendations to prolong shelf life of the packing. D-3.2 The bolts shall be covered with heavy grease to protect them from rusting, and the packing shall be wrapped in plastic wrap to protect them from deteriorating environmental conditions. D-4

Maximum Allowable Operating Pressure (MAOP)

The method of installing PLIDCO Weld+Ends determines the MAOP of the coupling. D-4.1 UnWelded MAOP Ratings After completing the installation and prior to welding the coupling to the pipe, the rating is defined as the "UnWelded MAOP Rating". The rating Page 29 of 39



for sizes 2-60" are listed in Table D-1 for single row of clamping screws and Table D-2 for double rows of clamping screws. D-4.2 Packing Material's "Sealant Strength" Pressure Limitations D-4.2.1

Silicone packing is limited to a "Sealant Strength" of 1000 psig.

D-4.2.2 Viton and Buna-N packing have no pressure limitations for "Sealant Strength". The MAOP should be equal to the UnWelded MAOP D-4.3 Welded MAOP Ratings After welding, the coupling is conisedred as anchored and it has higher rating defined as "Welded MAOP Rating". The rating for sizes 2-60" are listed in Table D-1 for single row of clamping screws and Table D-2 for double rows of clamping screws. Prior to welding, if it is determined that the total longitudinal forces exerted on a coupling will exceed the total gripping strength of it's clamping screws, the ends of the line shall then be anchored using a tie rod arrangement as shown in Saudi Aramco Standard Drawing AC-036655. D-4.4 Derated MAOP for Thin-Wall Pipes For PLIDCO Weld+Ends that will be installed on thin-wall pipes, the MAOP should be derated because the applied torque should be decreased. Refer to Table D-3 for derated values of MAOP. D-5

Installation

D-5.1 Preparation of Pipe Ends D-5.1.1 Select the location of pipe cuts so that the coupling's clamping screws can grip on a smooth, unpitted surface and the packing material can form a tight even seal. Remove any coatings or general corrosion around the entire area to be coupled. Longitudinal or spiral weld seams shall be ground flush with the pipe wall and all burrs removed. If the coupling is to be welded after installation, the pipe wall thickness in the vicinity of the fillet girth welds shall be checked by ultrasonic testing (U.T.) to ensure there is a minimum of 5.1 mm (0.20 in.) around the girth weld area.

Page 30 of 39



D-5.1.2 Check the diameters at both ends of the pipe to be coupled for out-of-roundness and repair if necessary using external line-up clamps or internal jacking. No other special preparation of pipe ends is required. D-5.2 Inspection of Weld+Ends Inspect the coupling for evidence of corrosion, fouling, and damaged packing. Be sure all the screws are free to turn and that no sand or any foreign material is in the packing grooves. One practical method of checking the packing is the thumb nail test. Push your thumb nail into the exposed packing. If the packing returns to the original shape, it should be acceptable for use. If the thumb nail imprint stays, the packing shall be replaced. D-5.3 Tightening the Clamping Screws D-5.3.1 Use manufacturer recommended procedure and torque for tightening the clamping screws. D-5.3.2 For thin-wall pipe of less than Sch. 40 or ½ inch, the clamping screws shall be tightened to the recommended torque values as shown in Table C-3 the torque and pressure derating graphs for thin wall pipe. These lesser clamp screw torque values shall be used to prevent damage to the pipe ends. D-5.3.3 In order to obtain a tight fit with equal and accurate clamp screw torque values, the following steps shall be followed: Step 1)

Center the Weld+Ends using the clamp screws at the 12, 6, 3, and 9 o'clock positions. These screws are only hand tightened (snug).

Step 2)

Adjust the gap between the pipe and coupling interface to ensure equal spacing. It is very important to provide a concentric, equal gap between this interface to ensure an optimum packing seal when the thrust screws are tightened.

Step 3)

Hand tighten any remaining clamp screws and adjust the gaps as stated in Steps 1 and 2.

Step 4)

Advancing circumferentially, begin torquing the clamping screws to equal portions of their final recommended torque value. Check the gaps and adjust them to ensure uniformity. Page 31 of 39


Step 5)


Repeat Step 4 several times until the final recommended torque is achieved. A final torque and gap check of all the clamping screws is recommended.

D-5.3.4 Tightening the Thrust Screws Thrust screws activate the seal packing. These screws are tightened AFTER the clamping screws are torqued. Tighten the thrust screws using the following steps: Step 1)

Tighten all screws until they are snug.

Step 2)

Advance each screw about 18 of a turn before advancing to the next, adjacent screw. Repeat this process as many times as necessary until the manufacturer recommended torque is reached.

Step 3)

Pressurize the line slowly and steadily without surges or slugging, which could vibrate and pull the line ends from the coupling. Do Not exceed the lesser value of the following: i)

The recommended UnWelded MAOP of the coupling.

ii)

The maximum design pressure of the line.

iii) The maximum calculated pressure as stated in during welding if the coupling is to be welded to the pipeline. Step 4)

D-6

Tighten the thrust screws as required to stop any leaks that may have developed to complete the Weld+Ends installation. If welding is specified, refer to Section C-6.

Welding

D-6.1

All welding of PLIDCO Weld+Ends to piping shall conform to an approved Saudi Aramco Welding Procedure Specification, e.g., WPS No. PLIDCO-001.

D-6.2

The minimum remaining pipe wall thickness at the area to be welded shall be at least 5.1 mm.

Page 32 of 39



D-6.3

The line shall remain pressurized for at least ½ hour prior to any welding to ensure no leaks form. Tighten the thrust screws as required to stop any leaks that may have developed.

D-6.4

All welding shall be made with low-hydrogen electrodes. If the pipe wall thickness is less than 0.35 inches, all first layer weld passes onto the pipe shall be made using 2.4 mm diameter electrodes. Subsequent weld passes may be made with 3.2 or 4 mm diameter electrodes.

D-6.5

Weld surfaces, such as the clamping and thrust screws, and the coupling body and adjacent pipe surfaces, shall be free of oil, grease, moisture, rust, scale, paint, metallic coatings, or other foreign matter, prior to welding. Refer to SAES-W-012.

D-6.6

Prior to fillet welding the coupling to the pipe ends, a maximum fit-up gap of 3.2 mm between the two surfaces shall not be exceeded. If the fit-up gap exceeds 3.2 mm, a weld build-up (buttering) shall be made on the pipe at the deficient area to reduce the gap distance. Remove one clamp screw from each top end of the coupling to act as a vent during welding and as a pressure test point after welding.

D-6.7

Only the stringer bead weld technique shall be used for all root passes and all subsequent passes if the pipe wall thickness is less than ½ inch. For pipe wall thickness equal to or greater than ½ inch, either the stringer bead or weave technique may be used. The weave width shall not exceed three (3) times the diameter of electrode.

D-6.8

The temperature of the metal during welding should be monitored as per manufacturer recommendation to avoid damaging the seal.

D-6.9

The final girth fillet weld leg size shall be a minimum of 1.5 times the nominal pipe wall thickness.

D-6.10

The fillet weld profile shall be as smooth as possible and should be slightly concave. The toe of the fillet weld shall blend smoothly into the pipe wall. It shall be the responsibility the welding inspector to accept the final weld size and profile.

D-6.11

The Weld+Ends shall be welded using the following steps: Step 1) Tack weld all of the end thrust screws. Cut them off flush with the coupling face using a wheel grinder. Hold a metal strip between the bolt and pipe to prevent damaging the pipe wall with the grinder. Some projection of the outer edge of the bolt is acceptable.

Page 33 of 39



Step 2) Depending on the position of the coupling, and the proximity of it's ends, both of the Weld+Ends girth welds should be made at the same time. Where possible, use two welders at each end of the coupling to weld on opposite quadrants simultaneously. All passes on the girth fillet weld shall be in the following sequence: 1)

Weld from 3:00 to 12:00 o'clock position.

2)


3)


4)


Commentary Note: All of the thrust screw ends shall be welded over.

Step 3) Make a ¼ in. fillet weld, (at least two passes), around all of the clamping screws, except the ones used for venting and leak testing. After welding, either burn off or cold cut the remainder of the clamping screws just above the weld. Step 4) Apply an air test (5 to 10 psi) at each end of the coupling through the top clamping screw holes. Put soap solution over all the welds and check for leaks. Any areas found leaking shall be ground out, re-welded and air tested as previous. Step 5) Upon completion of the air test, replace the remaining clamp screws at each end of the coupling. Tighten the clamp screw as described in section D-5.3. Weld and cut off the screw ends as described in Step 4.

Page 34 of 39



Table D-1: Maximum Allowable Operating Pressure (MAOP) Ratings Standard PLIDCO Weld+Ends with Single Rows of Clamping Screws* Coupling Size (inches)

Coupling Body Spec.

2

Unweld ed MAOP

Welded MAOP

MPa

(psig)

MPa

(psig)

A519 Gr. C 1018-1026

6.89

(1000)

13.79

(2000)

3

A106 Gr.B

6.89

(1000)

13.79

(2000)

4

A106 Gr.B

6.89

(1000)

13.79

(2000)

6

A106 Gr.B

4.80

(696)

13.79

(2000)

8

A106 Gr.B

3.53

(513)

13.79

(2000)

10

A106 Gr.B

2.73

(396)

10.34

(1500)

12

A106 Gr.B

2.26

(328)

8.27

(1200)

14

A106 Gr.B

2.14

(311)

8.27

(1200)

16

A106 Gr.B

1.64

(238)

8.27

(1200)

18

A285 Gr.C

1.73

(251)

8.27

(1200)

20

A285 Gr.C

1.40

(203)

8.27

(1200)

22

A285 Gr.C

1.74

(252)

8.27

(1200)

24

A285 Gr.C

1.46

(212)

8.27

(1200)

26

A285 Gr.C

1.24

(180)

6.89

(1000)

28

A285 Gr.C

1.068

(155)

6.89

(1000)

30

A285 Gr.C

0.931

(135

6.89

(1000)

31

A285 Gr.C

0.875

(127)

6.89

(1000)

32

A285 Gr.C

1.096

(159)

6.89

(1000)

34

A285 Gr.C

0.965

(140)

6.89

(1000)

36

A285 Gr.C

0.861

(125)

6.89

(1000)

38

A285 Gr.C

0.869

(126)

6.21

(900)

40

A285 Gr.C

0.786

(114)

5.52

(800)

42

A285 Gr.C

0.710

(103)

5.52

(800)

46

A516 Gr.70

0.696

(101)

4.48

(650)

48

A516 Gr.70

0.634

(92)

4.12

(600)

48

A516 Gr.70

0.634

(92)

6.89

(1000)

56

A516 Gr.70

0.655

(95)

5.52

(800)

56

A516 Gr.70

0.723

(105)

6.89

(1000)

60

A516 Gr.70

0.599

(87)

5.52

(800)

Note 1: Sizes 2 through 42 inch use silicone packing. Sizes 46 thru 60 inch use Viton.

Page 35 of 39



Table D-2: Maximum Allowable Operating Pressure (MAOP) Ratings Special PLIDCO Weld+Ends with Double Rows of Clamping Screws* Coupling Size (inches) 8 8 10 10 12 12 12 14 14 16 16 18 18 20 20 20 22 22 24 24 24 30 Buna-N Packing 30 30 31 Buna-N Packing 32 36 40 42 48 56 60

Coupling Body Spec. A106 Gr.B A106 Gr.B A106 Gr.B A106 Gr.B A516 Gr.70 A106 Gr.B A106 Gr.B A516 Gr.70 A106 Gr.B A516 Gr.70 A516 Gr.70 A516 Gr.70 A285 Gr.C A516 Gr.70 A516 Gr.70 A285 Gr.C A516 Gr.70 A516 Gr.70 A516 Gr.70 A516 Gr.70 A285 Gr.C A285 Gr.C or A515 Gr. 55 or A516 Gr.55 A516 Gr.70 A285 Gr.C A285 Gr.C or A515 Gr.55 or A516 Gr.C A285 Gr.C A516 Gr.70 A285 Gr.C A285 Gr.C A516 Gr.70 A516 Gr.70 A516 Gr.70

Unwelded MAOP MPa (psig) 6.19 (898) 6.19 (898) 4.78 (693) 4.78 (693) 3.96 (574) 3.96 (574) 3.96 (574) 3.75 (544) 3.75 (544) 2.87 (416) 2.87 (416) 3.03 (439) 3.03 (439) 2.45 (355) 2.45 (355) 2.45 (355) 3.04 (441) 3.04 (441) 2.56 (371) 2.56 (371) 2.56 (371) 1.63 (236)

Welded MAOP MPa 13.79 6.89 13.79 6.89 20.68 13.79 6.89 20.68 6.89 20.68 13.79 20.68 6.89 20.68 13.79 6.89 20.68 13.79 20.68 13.79 6.89 6.89

(psig) (2000) (1000) (2000) (1000) 3000) (2000) (1000) (3000) (1000) (3000) (2000) (3000) (1000) (3000) (2000) (1000) (3000) (2000) (3000) (2000) (1000) (1000)

1.63 1.63 1.63 1.53

(236) (236) (236) (222)

6.89 13.79 6.89 6.89

(1000) (2000) (1000) (1000)

1.92 1.51 1.38 1.24 1.11

(278) (219) (200) (180) (161)

6.89 13.79 6.89 6.89 6.89 6.89 6.89

(1000) (2000) (1000) (1000) (1000) (1000) (1000)

Notes: 1.

All couplings are color coded white and restricted to submarine pipe repair.

2.

All coupling supplied with Viton packing unless otherwise note.

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Table D-3: Maximum Allowable Operating Pressure (MAOP) Ratings and Clamping Screw Torque Values for Special PLIDCO Weld+Ends on Thin-Wall Pipes Diameter

Thickness

3" 3" 3" 3" 3" 3" 4" 4" 4" 4" 4" 4" 6" 6" 6" 6" 6" 6" 8" 8" 8" 8" 8" 8" 10" 10" 10" 10" 10" 10" 12" 12" 12" 12" 12" 12" 14" 14" 14" 14" 14" 14" 16" 16" 16" 16" 16" 16" 10" 10" 10" 10" 10" 10"

0.188 0.198 0.208 0.217 0.227 0.237 0.156 0.172 0.188 0.205 0.221 0.237 0.156 0.181 0.206 0.230 0.255 0.280 0.188 0.215 0.242 0.268 0.295 0.322 0.188 0.223 0.259 0.294 0.330 0.365 0.250 0.281 0.312 0.344 0.375 0.406 0.228 0.270 0.312 0.354 0.396 0.438 0.250 0.300 0.350 0.400 0.450 0.500 0.188 0.223 0.259 0.294 0.330 0.365

Clamping Screw Torque 75 80 85 90 95 100 75 80 85 90 95 100 30 44 58 72 86 100 50 60 70 80 90 100 70 76 82 88 94 100 75 80 85 90 95 100 60 68 76 84 92 100 40 52 64 76 88 100 70 76 82 88 94 100

MAOP 310 497 685 872 1060 1247 310 474 638 803 967 1131 160 267 374 482 589 696 155 227 298 370 441 513 145 195 245 296 346 396 80 130 179 229 278 328 100 142 184 227 269 311 57 93 129 166 202 238 145 195 245 296 346 396

Diameter 18" 18" 18" 18" 18" 18" 20" 20" 20" 20" 20" 20" 22" 22" 22" 22" 22" 22" 24" 24" 24" 24" 24" 24" 26" 26" 26" 26" 26" 26" 30" 30" 30" 30" 30" 30" 36" 36" 36" 36" 36" 36" 40" 40" 40" 40" 40" 40" 48" 48" 48" 48" 48" 48"

Thick ness 0.25 0.3 0.35 0.4 0.45 0.5 0.312 0.3496 0.3872 0.4248 0.4624 0.5 0.25 0.3 0.35 0.4 0.45 0.5 0.312 0.3496 0.3872 0.4248 0.4624 0.5 0.312 0.3496 0.3872 0.4248 0.4624 0.5 0.312 0.3496 0.3872 0.4248 0.4624 0.5 0.312 0.3496 0.3872 0.4248 0.4624 0.5 0.312 0.3496 0.3872 0.4248 0.4624 0.5 0.375 0.4 0.425 0.45 0.475 0.5

Clamping Screw Torque 50 70 90 110 130 150 125 130 135 140 145 150 50 70 90 110 130 150 125 130 135 140 145 150 125 130 135 140 145 150 125 130 135 140 145 150 40 62 84 106 128 150 50 70 90 110 130 150 125 130 135 140 145 150

MAOP 50 90.2 130.4 170.6 210.8 251 80 104.6 129.2 153.8 178.4 203 50 90.4 130.8 171.2 211.6 252 80 106.4 132.8 159.2 185.6 212 50 76 102 128 154 180 40 59 78 97 116 135 32 50.6 69.2 87.8 106.4 125 18 37.2 56.4 75.6 94.8 114 50 58.4 66.8 75.2 83.6 92

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Appendi x E – Hydro gen Induc ed Crac king (HIC) Deci si on Tree

SWC

= Step Wise Cracking.

t

= Wall thickness of vessel or pipe.

Depth

= defect depth below nearest surface, whether ID or OD.

(a through i)

= See Notes.

Notes – Hydrogen Induced Cracking (HIC) Decision Tree a) Once suspected hydrogen induced cracking (HIC) damage is located, it should be surveyed to determine the size and shape of the damaged area, whether the suspected HIC occurs as small isolated spots or nearly continuous fields, and the depths at which the suspected HIC is detected. Such surveys are normally conducted using ultrasonic examination.

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SAEP-310

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