PROCEDURES

PROCEDURES

General Index:

a) Fabrication & Installation ProcedurePag.21.0 General arrangements on site

2.0 Site plan & equipment

3.0 Manufacturing / fabrication process specification

4.0 Erection / installation process specification

b) Welding ProcedurePag. 91.0 Cutting, Fitting and Alignment

2.0 Cleaning of surface to be welded

3.0 Preheating treatment

4.0 Welding process specification

5.0 Post weld heat treatment

6.0 Repair of weld defects

c) Non-destructive testing procedurePag.201.0 Welding process check

2.0 Welders & welding operator qualification check

3.0 Ultrasonic testing specification

4.0 Radiographic examination specification

5.0 Visual inspection requirement

6.0 Marking & Reports

7.0 Hydrostatic testing

d) Painting ProcedurePag.36

1.0 Field blasting & painting procedure

2.0 Field touch up requirements

3.0 Inspection requirements

4.0 General painting requirements

FABRICATION & INSTALLATION PROCEDURE

Index:

1.0 General Arrangements on SitePag.3

2.0 Site plan & equipmentPag.3

3.0 Manufacturing / Fabrication process specificationsPag. 3

3.1 Construction characteristicsPag.5

3.2 WeldingPag. 6

4.0 Test, inspection, assembly and installationPag.6

4.1 GeneralityPag. 6

5.0 Erection / installation process specificationsPag.6

1.0 General Arrangements on site

Astaldi-CBI prepared an area for the penstock fabrication, quality control, sand blasting and painting shops. These facilities are located in the Unduavi Valley, in a suitable area in Sacahuaya close to the Yanacachi Penstock and Powerhouse. Nearby a camp facilities are also constructed for personnel working in the Penstock Manufacture and Erection activities.

A factory supervisor with a staff of 40 to 50 workers (according to work progress) are employed for pipe fabrication activities and a erection supervisor with a staff of 20 to 40 workers pipeline (according to work progress) are employed for the erection and testing of the Penstock. Welders and other personnel which have already worked with Astaldi-CBI in other similar jobs (Zongo and San Jacinto) are employed as far as possible, there will be 2 qualified Inspectors, 1 for the manufacturing process and 1 for the erection process. Welders and inspectors will be trained and certified by approved welding experts, and according to the attached "Qualification Procedures for Welders.

Nondestructive tests will be carried out by Astaldi-CBI's inspectors under the supervision of a welding expert who will issue Quality Control Reports and Certificates of Tests that have been carried out during fabrication.

2.0 Site plan & equipment

Site plan attached.

TAQUESI PROJECT PENSTOCK MANUFACTURING SHOP FACILITIES.

No. 1 1000 Square Meters of the main body structure in steel with steel roof, steel side walls and gates, for Penstock Manufacturing Shop;

No. 1 200 square Meters of the main body structure in steel with steel roof, steel side walls and gates, for sand Blast and Painting activities;

No. 2 5 Tons Overhead Traveling Bridge Crane - lifting capacity six (6) meters from bottom.

No. 1 12 Tons Caterpillar V300B Fork Lift with Diesel Motor;

No. 1 Diesel Generating Set, 150KW;

No. 1 Steel Plates Guillotine Shear - Capacity 25 x 3000 Millimeters;

No. 4 Oxyacetylene Single or Multi Torch with motorized Cutting Machine for cutting and beveling of Steel Plates.

No. 1 Three Roller Bending Machine with 16 x 2550 millimeters Capacity - minimum radius of 200 millimeters

No. 1Three Roller Bending Machine with 45 x 3000 millimeters Capacity - minimum radius of 500 millimeters

No. 4Motorized adjustable Pipe Rollers Capacity of six (6) Ton load with twelve (12) Tons Rotation.

No. 15Free adjustable Pipe Rollers. Capacity of six (6) Tons Load

No. 1Automatic Submerged Arc welding Machine ESAB Type, mounted over motorized manipulator with DC Generator of 800 Amps. The Manipulator has arm four (4) meters long and three (3) meters supporting column plus the standing platform. The motorized system moves over rails and have the possibility to weld longitudinal and circumferential joints inside and outside of the pipes.

No. 3 Submerged ESAB and Lincoln Tractor type with 800 and 600 Amps DC Generators. The Tractors over special guides has the possibility to weld longitudinal and circumferential outside and inside joints in a fixed position, with pipe over Motorized Tube Rollers. (Normally the circumferential inside joints would be welded with a manipulator)

No.14ESAB DC 400 Amps Welding Machine for manual welding.

No.2ESAB DC 600 Amps Welding Machine for manual welding and for Arc Air Torch.

No. 1ESAB DC 400 Amps Gas Semi-Automatic Welding Machine

No. 3High Frequency Generator with four (4) Inlet each for Grinding Machines

No. 8High Frequency Angular Grinding Machine

No. 1Directional x-ray Apparatus - 200 kW for Quality Control

No. 1Ultrasonic Apparatus for Quality Control

No. 1Alternative Motorized Saw

No. 2Heating and Treatment Ovens for Submerged Arc Welding Flux Electrical Type

No. 2Vertical Heating and Treatment Ovens for Welding electrodes Electrical Type - Around 1200 Electrodes capacity

No. 2Electrical Motorized Air Compressors for Arc Air Torches

No. 1Diesel Motor Welding Machine - 600 Amps

No. 2Pick-up or Shop service.

The shop is complete with all the electrical and distribution panels, lighting system, air distribution system and all necessary hand tools such as hydraulic and mechanical jacks, tir-4, lift pulleys, lifting cables, individual tools and all the protective clothing required. Also incorporated in the shop will be tools spare parts and consumable materials store. Store for welding materials, first aid infirmary, workshop office, x-ray laboratory and permanent material store.

For the Taquesi project the shop will also be provided with the following:

No. 1Air Compressor of High Capacity - 7 Bars,

No. 2Sand Blasting Machines,

No. 1Infrastructure to meet environment basic requirements.

No. 2 Cable way (Blondins) load capacity 5 Tons.

3.0 Manufacturing / Fabrication Process Specifications

ASTALDI-CBI, due to inaccessibility of the job-site shall manufacture the Penstock, Bends, Manifolds, Manholes and Expansion joints in Bolivia.

Fabrication shall comply with ASTM, AWWS, AWS standards and specifications. Nondestructive testing will be 100% ultrasonic testing, and 15% for pipe factory and 60% pipeline radiographic examinations of circumferential and longitudinal joints. Depending on the performance of the welders and radiographic examination records, the percentage requirement of radiographic examination can be reduced.

The manufacturing process will be as follows:

Check drawings, QA handbook and welder certificates;

Receiving material and Certificates test Result from Mill;

Marking plates;

Squaring, cutting plates with guillotine shear or oxyacetylene;

Beveling and special cuttings with oxyacetylene;

Roll bending with machine for plates 8(30 mm thick. Use jig to control radius;

Longitudinal tack welding;

Longitudinal internal/external submerged arc welding;

Assembling of pipes;

Circumferential internal submerged arc welding;

Circumferential external submerged arc welding;

Check dimensions and roundness (Sample sheet is attached);

Visual dimensions check and perform NDE;

Repairs of faulty elements;

Perform NDE of repaired elements;

Pipe welding sheet will be prepared (Sample sheet is attached);

Sandblasting;

Painting;

Painting inspection;

Each pipe will be marked with an ID and Position number.

3.1 Construction characteristics

Materials:

The steel utilized for manufacturing the Penstock is ASTM A537 CL. 1 - produced in Italy and all other welding materials according to WPS (Welding Procedure Specifications).

Material characteristics

a) The metal plates for the manufacturing the Penstock shall be ASTM A537 CL. 1 -

produced in Italy shall be produced in compliance with applicable specifications;

b)All welding materials shall be in compliance with WPS and applicable specifications;c) The steel used in the construction of the other parts such as Bends, Manifolds, Flanges and Expansion Joints shall also be ASTM A537 CL. 1;

d) Anchor rings for pipes AP11(AP17 will be manufactured and welded to the pipes in the shop;

e) Manholes will be placed according to shop drawings and will be manufactured in the shop;

f) Expansion joints will be manufactured in the shop. Assembling of expansion joints will be made accordance with specifications, pipes will be cut according to a thermal expansion charts, depending on the temperature and length in which the expansion joint is installed;Saddle supports steel plate, 8 mm thick, shall have a half moon of 120( form, and shall be welded to anchor hooks for second stage concrete;

Pipes shall be completely painted in the shop, except for 20 cm. at both ends that shall be painted on the job site, after erection and inspections.

e) The flange and coupling tie rod, bolt and nut dimension after machining shall not be inferior to nominal values.

f) The average internal diameter of every pipe or element, established by the measure of the external development at the two ends and of the thickness, shall not be different from the theoretic diameter more than 0.3% plus or minus with a maximum of 5 mm.

g) The ovalization of every pipe or segment, determined by the maximum length difference of almost two diameters perpendicular between them, can not be greater than 0.01D, D been the theoretic internal diameter.

h) Anchor rings shall be fabricated and welded to the pipes in the workshop according to approved shop drawings.i) Mechanical expansion joints shall be manufactured in the workshop according to approved shop drawings.

j) The theoretic mass of every pipe or element appear on the single mass list an the shop drawings on the basis of the final project for the piping, a variation less than 5% is accepted. The theoretic mass shall be calculated on the basis of the nominal dimensions and mass volume of 7.85 kg/dm3.

3.2 Welding

Materials used in the construction of welded parts shall comply with the requirements for materials given an shall be proven of weldable quality.a) Records of the names of the welders who make each weld shall be maintained. Welders and welding operators shall be qualified and qualification records shall be available for audit.

b) Two sample test will made, for tensile test and for bend test as per attached sheet. These tests will be certified by a qualified firm.

c) Welding of the pipes in the workshop will be by automatic welding machines. Welds will be butt welds from inside and outside. In tunnel sections welding will be from inside only against external counter bars.

d) The edge to be butt welded shall be completely free from exfoliation, cracks or incision, rust, calamine, humidity and shall be, therefore, submitted to the checks and adequately protected.

e) When the temperature of the elements to be welded is lower than +5C, and anyhow when the room temperature is lower than 5C or there is excessive ventilation (with influence on the protection of the arc), the welding operations shall be made with appropriate methods so that the cooling, after the welding, is sufficiently slow to guarantee from cracking risk.

f) The removal of alignment jacks, tack welds and/or other possible appendixes shall be done by grinding and subsequent visual examination of the grinded areas .

4.0 Tests, inspection, assembling and installation

4.1 Generality

For planning and checking of the construction phases (manufacturing), for assembling (erection) and put in service (starting), the formulation related to the tests and control and for certified documentation, are valid with the following specification.

a) For site activity, welding sheets shall be used;

b) Certified documentation relating to tests and checks will be related with the single check and test carried out and will state the checked values and their evaluation, the used method, the referring standards or the procedure used.

5.0 Erection and installation process specification

The erection of Yanacachi Penstock will be carried out in two phases. In the first phase, the cable way (Blondins) will be installed for erecting the pipe sections going from AP17 to AP15. In the second phase the Blondins will be moved for erecting the line going from AP15 to AP11.

The pipe sections located in anchor points AP17 to AP11 will be positioned first, leveled according to plan. The pipe will be welded to the anchor stay rods prepared during 1( phase concrete. After 2( phase concrete of the block, the erection of pipe sections will follow from one AP point to the other AP point and so forth up to Yanacachi tunnel Portal.

The procedure for Penstock installation on job site is as follows:

The pipes will be transported from the pipe factory to the erection site on a truck with special supporting saddles;

Set up equipment, tools, temporary support shall be ready on the erection site including ventilation for the steel lined sections;

Pipes will be unloaded with a cable way (Blondins) Lifting Capacity 5 Tons;

When working on slope and elevation areas, internal and external scaffold will be prepared and erected.

The pipes will be lifted brought to position with the Blondins, a 60 cm alignment slide will be welded and the joint spaced with a 2-3 mm spacer;

If necessary an aux. support will be welded on the front part to maintain the pipe in position;

The pipe will be aligned and edges tack welded;

The inside welding shall be carried out first;

The exterior will be cleaned with arc-air and welded from the exterior;

Ultrasonic and radiographic tests will be made and eventual repairs will be carried-out;

The welded part will be painted and the painting will be checked;

Anchor rings for pipes AP11(AP17 will be manufactured and welded to the pipes in the shop.

Manholes will be placed according to approved shop drawings and will be manufactured in the shop.

Expansion joints will be manufactured in the shop. Assembling of expansion joints will be made in accordance with specifications. Slip pipes will be cut according to a thermal expansion charts, depending on the temperature and length in which the expansion joint is installed;

Saddle supports steel plate, 8 mm thick, shall have a half moon of 120( form, and shall be welded to anchor stay hooks.

Welding will proceed in accordance with WPS here after specified. For security reasons during night shifts, the interior of pipe will be welded and during day shifts the exterior will be welded;

Painting and controls will follow;

For erection of steel lined tunnel sections, a trolley mounted on rails will be used to transport the pipes, auxiliary foot supports welded to the pipe ends will be left to concrete. Welding will be from inside only against external counter bars ;

Visual inspection will be carried-out in the interior of the piping;

Covers of the manholes will be placed, o-rings checked;

Expansion joints will be tightened to torque;

Finally the piping will be filled with water and leak tested ;

Infiltration and leak inspections and controls will be carried-out;

A hydropressure test will be carried out to underground piping prior to covering. Hollow blind flanges with adequate safety valves and manometers will be welded at the 2 ends of the piping. The piping will be filled with water; pressure will be gradually brought to 1-1/2 times the design pressure of the piping and maintained for 30 minutes; after a visual control of the piping the pressure will be lowered to the design pressure and maintained at this pressure for the time required to permit inspection of the piping. If during test defects appear, the defectous element will be repaired in accordance to specifications and the hydrostatic test will be repeated. The blind flanges will be removed, and the erection will proceed.

Erection of Chojlla Penstock:

The same procedure of Yanacachi Penstock will be followed, except for stretch between AP25 and AP26 where the cable crane can not be installed due to the presence of a high voltage Lines. On this stretch, a construction access road will be constructed to carry out the penstock civil and erection works.Annex C erection plans Yanacachi and Chojlla

WELDING PROCEDURE

Index:

1.0 Cutting, Fitting and alignmentPag.10

2.0 Cleaning of surface to be weldedPag.10

2.1 Preparation of base metalPag.10

3.0 Preheating treatmentPag. 11

3.1 Weather condition for weldingPag. 11

3.2 Preheat and interpass temperaturePag.11

4.0 Welding process specificationsPag.11

4.1 General welding procedure specifications for shielded metal arc processPag.11

4.2 Control of parametersPag. 13

4.3 TechniquePag.13

4.4 General welding procedure specifications for submerged arc welding processPag.14

4.5 Filler metalPag.15

4.6 Control of parametersPag.15

4.7 TechniquePag.16

5.0 Post weld heat treatment (Removed. Not applicable)Pag.17

6.0 Repair of weld defectsPag.17

6.1 Repair of weld defectsPag.17

6.2 Appearance of weldingPag.17

6.3 RepairsPag.17

6.4 Re-examination of repaired areasPag.17

1.0 Cutting, Fitting and Alignment

(a) When plates are shaped by oxyacetylene or arc cutting, the edges to be welded shall be uniform and smooth and shall be freed of all loose scale and slag accumulations before welding .

(b) Plates that are being welded shall be fitted, aligned, and retained in position during the welding operation.

(c) Bars, jacks, clamps, tack welds, or other appropriate means may be used to hold the edges of parts in alignment. Tack welds used to secure alignment shall either be removed completely when they have served their purpose, or their stopping and starting ends shall be properly prepared by grinding or outer suitable means so that they may be satisfactorily incorporated into the final weld. Tack welds, whether removed or left its place, shall be made using a fillet weld or butt weld procedure qualified in accordance with Section IX. Tack welds to be left in place shall be made by welders qualified in accordance wills Section IX, and shall be examined visually for defects, and if found to be defective shall be removed.

(d) The edges of butt joints shall be held during welding so that the tolerances are not exceeded in the completed joint. When fitted girth joints have deviations exceeding the permitted tolerances, the head or shell ring, whichever is outoftrue, shall be reformed until the errors are within the limits specified. Where fillet welds are used, the lapped plates shall fit closely and be kept in contact during welding.

(e) (Removed. Not applicable)

2.0 Cleaning of surfaces

Cleaning of surfaces to be welded

(a) The surfaces to be welded shall be clean and free of scale, rust, oil, grease, slag, detrimental oxides, and other deleterious foreign material. The method and extent of cleaning should be determined based on the material to be welded and the contaminants to be removed. When weld metal is to be deposited over a previously welded surface, all slag shall be removed by a roughing tool, chisel, chipping hammer or other suitable means, as to prevent inclusion of impurities in the weld metal.

(b) Cast surfaces to be welded shall be machined chipped, or ground to remove foundry scale and to expose sound metal.

(c) The requirements in (a) and (b) above are not intended to apply to any process of welding by which proper fusion and penetration are otherwise obtained and by which the weld remains free from defects.

2.1 Preparation of base metal

The edges or surfaces of the pieces to be joined by welding shall be prepared by flame cutting, plasma arc cutting, arc gouging, machining, shearing, grinding, or chipping and shall be cleaned of detrimental oil, grease, scale and rust. The edges of the pieces may have a protective coating applied to them which need not be removed before they are welded unless specifically prohibited by the specific WPS.

3.0 Preheating treatment

No preheating is required except as an aid for removing surface moisture prior to the start of welding, except as indicated in the WPS.

3.1 Weather conditions for welding

Welding shall not be performed when the surfaces in the welding area (within 6" (15.2cm) of the arc) are wet; nor in periods of high winds unless the welder and the pieces to be welded are properly protected.

3.2 Preheat and interpass temperature (When required by the specific WPS)3.2.1 Method

If required, preheat and/or interpass temperature shall be achieved by any suitable means which will keep the temperature of the joint within the specified limits shown on the specific WPS. The method of pre-heating and the heat source to be used may be changed or supplemented as deemed necessary or desirable.

3.2.2 Continuous Preheat:

When continuous preheat is required, it shall be a uniform preheat during the time of welding, obtained by pipe burners or strip heaters. On vertical joints or radial joints the required preheat is necessary along the entire length.

On circumferential joints of large diameter vessels, the required reheat is necessary along the area or areas being welded. When welders are spaced around the entire circumferential joint on small diameter vessels, the entire joint shall be preheated.

3.2.3 Monitoring:

Joints requiring preheat and/or interpass temperature control will be checked before and/or during welding of the joints to ensure that the minimum temperature is being maintained and that the maximum interpass temperature is not exceeded.

For temperance greater than or equal to 150 F (66 C), temperature indicating crayons will normally be used to determine that the joint is at the required minimum temperature or above, but not exceeding the maximum interpass temperature.

4.0 Welding process specification

4.1 General welding procedure specifications for shielded metal arc process

Scope

This is a general Welding Procedure Specification to be used with a specific Welding Procedure Specification (WPS) when referred on the WPS. In case of conflict between this documents and the specific WPS, the specific WPS shall govern.

Reference

ASME Boiler and Pressure Vessel Code, Section IX. Welding Qualifications, Edition and Addenda as shown on the specific WPS.

Procedure qualifications

WPS for the project have been supplied by the welding materials supplier ESAB.

Preparation on base metal

The edges or surfaces of the pieces to be joined by welding shall be prepared by flame cutting, plasma arc cutting, arc gouging, machining, shearing, grinding, or chipping and shall be cleaned of detrimental oil, grease, scale and rust. The edges of the pieces may have a protective coating applied to them which need not be removed before they are welded unless specifically prohibited by the specific WPS.

4.1.1 Weather conditions for welding

Welding shall not be performed when the surfaces in the welding area (within 6" (15.2cm) of the arc) are wet; nor in periods of high winds unless the welder and the pieces to be welded are properly protected.

4.1.2 Joints (QW-402)

4.1.2.1Root Opening

Normal root opening shall be 0-1 1/4" (0 m-m - 6.4 mm). See contract drawings for the specific joint detail. Spacer bar joints are considered 0" gap.

4.1.2.2Wide Gaps

The following technique shall be used for welding joints with wide gaps which exceed twice that specified on the applicable contract drawing. When zero gap is specified on the contract drawings, gaps exceeding 3/16 (4.8 mm) shall be reduced as outlined below to a 3/16" (4.8 mm) or smaller gap. Maximum weld build-up shall be T (where T is the thickness of the plate) for each plate edge or 1/2" (12.7 mm) whichever is smaller.

Method:

Plate edge build-up shall be done with a welding, procedure approved for contract use. Weld passes shall be deposited utilizing a stringer bead technique to restore the plate edges to the gap and approximate joint configuration as shown on the contract drawing.

On single or square butt joints a temporary back-up bar of compatible material may be used. The edges should be built-up using stringer beads to restore the joint to the gap and approximate joint configuration as shown on contract drawings, before tying the edges together.

The temporary back-up bar shall be removed by gouging, chipping or grinding to clean, sound-metal the second side.

4.1.2.3Narrow Gaps

The following technique shall be used for correcting joints with gaps less than specified on the applicable contract drawing which are not sufficiently wide to allow free manipulation of the electrode in the joint.

Method:

The plate edges of the joint shall be prepared by flame cutting, plasma arc cutting, grinding arc gouging or chopping to restore the joint to the gap and approximate joint configuration shown on the contract drawings. Gouging dross, burning dross, or reside shall be removed by brushing or grinding before welding commences.

4.1.2.4Retainers

Nonmetallic retainers or non-fusing metal retainers may only be used when they are specified on the specific WPS.

4.1.2.5Backing

Double welded groove welds are considered welding with backing.

For single welded groove welds, the backing shall be as specified in the specific WPS.

4.2 Control of parameters (QW-409)

Control of amperes and volts will be by the burn-off-rate (BOR) method. Control of the heat input/volume of weld metal will be by bead size where applicable.

4.3 Technique (QW-410)

4.3.1 Tack Welds

Tack welds used to secure alignment shall either be removed completely, when they have served their purpose, or their stopping and starting ends shall be properly made and prepared so that they may be satisfactorily incorporated into the final weld. Defective tack welds shall be removed.

4.3.2 Cleaning

Pneumatic or other mechanical tools may be used as an aid to cleaning slag or flux from the weld. Such mechanical cleaning is not considered peening. Slag or flux remaining on any weld bead shall be removed before laying down the next successive weld bead to the extent required to assure complete fusion. Cleaning of stainless steel or Nickel-Chromium-Iron alloy weld metal or base metal shall be with uncontaminated stainless steel brushes, grinding discs or wheels or by other suitable means. All completed welds shall have the weld spatter removed and welds not ground shall be wire brushed.

4.3.3 Appearance of Welding

Any defects that appear on the surface of any weld bead shall be removed by chipping, or arc gouging before depositing the next successive weld bead. The welding current and manner of depositing the weld metal shall be such that there shall be practically no undercutting of the finished joint except as permitted by the applicable Code. The surface of welds shall be free from coarse ripples or groove, overlaps, and abrupt ridges or valleys. Reinforcement shall be according to the applicable Code.

4.3.4 Treatment of Backside of Welding Joint

The back side of double welded groove welds shall be prepared by chipping, grinding, or arc gouging to clean sound metal. The root of the groove shall be sufficiently wide to permit fusion and allowed free manipulation of the electrode. Gouging, dross or residue shall be removed by brushing or grinding before welding commences.

4.3.5 Peening

No peening shall be allowed unless specified on the specific WPS or unless specified in special instruction issued by the Welding and Q.C. Manager

4.4 General welding procedure specifications for submerged arc welding process (SAW)

Scope

This is a general Welding Procedure Specification to be used with a specific Welding Procedure Specification (WPS) when referenced on the WPS. In cases of conflict between this document and the specific WPS, the specific WPS shall govern.

Reference

ASME Boiler and Pressure Vessel Code, Section IX, Welding Qualifications, Edition and Addenda as shown on the specific WPS.

Procedure qualifications

WPS for the project have been supplied by the welding materials supplier ESAB.

Preparation of base metal

The edges or surfaces of the pieces to be joined by welding shall be prepared by flame cutting, plasma arc cutting, arc gouging, machining, shearing, grinding or chipping and shall be cleaned of detrimental oil, grease, scale ad rust. The edges of the pieces may have a protective coating applied to them which need not be removed before they are welded unless specifically prohibited by the specific WPS.

4.4.1 Weather condition for welding

Welding shall not be performed when the surfaces in the welding area (within 6" (15.2 cm) of the arc) are wet; nor in periods of high winds unless the welder and the pieces to be welded are properly protected.

4.4.2 Joints (QW-402)

4.4.2.1Root Opening

Normal root opening shall be 0- 1/4" (0 mm-6.4 mm). Spacer bar joints are considered 0" gap.

4.4.2.2Wide Gaps

The following technique shall be used for welding joints with wide gaps which exceed twice that specified on the applicable contract drawing. When zero gap is specified on the contract drawing, gaps exceeding 3/16" (4.8 mm) shall be reduced as outlined below to a 3/16" (4.8 mm) or smaller gap. Maximum weld build-up shall be T (where T is the thickness of the plate) for each plate edge or (12.7 mm) whichever is smaller.

Method:

Plate edge build-up shall be done with a welding procedure approved for contract use. Weld passes shall be deposited utilizing a stringer bead technique to restore the plate edges to the gap and approximate joint configuration as shown on the contract drawings.

On single or square butt joints, a temporary back-up bar of compatible material may be used. The edges should be built-up using stringer beads to restore the joint to the gap and approximate joint configuration as shown on contract drawings, before tying the edges together.

The temporary back-up bar shall be removed by gouging, chipping or grinding to clean, sound-metal before welding the second side.

4.4.2.3Narrow Gaps

The following technique shall be used for correcting joints with gaps less than specified on the applicable contract drawing which are not sufficiently wide to allow free manipulation of the electrode in the joint.

Method:

The plate edges of the joint shall be prepared by flame cutting, plasma arc cutting, arc gouging, or chipping to restore the joint to the gap and approximate joint configuration shown on the contract drawings. Gouging dross, burning dross, or residue shall be removed by brushing or grinding before welding commences.

4.4.2.4Retainers

Nonmetallic retainers or non-fusing metal retainers may only be used when they are specified on the specific WPS.

4.4.2.5Backing

Double welded groove welds are considered welding, with backing,

For single welded groove welds, the backing shall be as specified in the specific WPS.

4.5 Filler metal (QW-404)

Supplemental filler metals or supplementary powdered filler metals may only be used when specified on the specific WPS.

Flux from re-crushed slag shall not be used, unless specified on the specific WPS.

4.6 Control of parameters (QW-409)

Control of amperes and volts will be by amp and volt meters. Control of heat input/volume of weld metal will be by amperage, voltage, and travel speed control where applicable.

4.7 Technique (QW-410)

4.7.1 Tack Welds

Tack welds used to secure alignment shall either be removed completely, when they have served their purpose, or their stopping and starting ends shall be properly made and prepared so that they may be satisfactorily incorporated into the final weld. Defective tack welds shall be removed.

4.7.2 Cleaning

Pneumatic or other mechanical tools may be used as an aid to cleaning slag or flux from the weld. Such mechanical cleaning is not considered peening. Slag or flux remaining on any weld bead shall be removed before laying down the next successive weld bead to the extent required to assure complete fusion. Cleaning of stainless steel or Nickel-Chromium-Iron alloy weld metal or base metal shall be with uncontaminated stainless steel brushes, grinding discs or wheels or by other suitable means. All completed welds shall have the weld spatter removed and welds not ground shall be wire brushed.

4.7.3 Appearance of Welding

Any defects that appear on the surface of any weld bead shall be removed by chipping, or arc gouging before depositing the next successive weld bead. The welding current and manner of depositing the weld metal shall be such that there shall be practically no undercutting of the finished joint except as permitted by the applicable Code. The surface of welds shall be free from coarse ripples or groove, overlaps, and abrupt ridges or valleys. Reinforcement shall be according to the applicable Code.

4.7.4 Treatment of Backside of Welding Joint

Downflat:

The back side of double welded groove welds shall be prepared by chipping, grinding, or arc gouging to clean sound metal. If gouging is performed, dross or residue shall be removed by brushing or grinding before welding commences.

Horizontal:

When automatic submerged-arc process is used to weld horizontal groove welds, both sides may be welded simultaneously and no treatment of the back site of the joint is necessary to ensure complete penetration and fusion.

4.7.5 Peening

No peening shall be allowed unless specified on the specific WPS or unless specified in special instruction issued by the Welding and Q.C. Manager

4.7.6 Electrode Spacing (Multiple Electrodes)

Tandem Arc:

The centerline spacing between electrodes shall be a nominal 3/4" (19.1 mm).

Twin Arc:

The centerline spacing between electrodes shall be a nominal 5/6" (7.9 mm).

5.0 Postweld heat treatment

Postweld heat treatment is not required as per WPS.

5.1 Removed. Not applicable.

6.0 Repair of weld defects

6.1 Repair of weld defects

Defects, such as cracks, pinholes. and incomplete fusion, detected visually or by the hydrostatic or pneumatic test or by ultrasonic or x-ray examinations shall be removed by mechanical means or by thermal gouging processes, after which the joint shall be rewelded.

6.2 Appearance of Welding:

Any defects that appear on the surface of any weld bead shall be removed by chipping, or arc gouging before depositing the next successive weld bead. The welding current and manner of depositing the weld metal shall be such that there shall be practically no undercutting of the finished joint except as permitted by the applicable Code. The surface of welds shall be free from coarse ripples or groove, overlaps, and abrupt ridges or valleys. Reinforcement shall be according to the applicable Code.

6.3 Repairs

6.3.1When an imperfection is repaired by chipping or grinding and subsequent repair by welding is non required, the excavated area shall be blended into the surrounding surface so as to avoid sharp notches, crevices or corners.

6.3.2 When an imperfection is to be repaired by welding, after the imperfection is thought to have been removed and prior to making weld repairs, the area shall be examined by the applicable steps in the Procedure section of the Technique Procedure to ensure it has been removed or reduced to an acceptably sized imperfection.

6.4 Re-examination of repaired areas

Repaired areas shall be re-examined by examination methods that were originally required for the affected area, except that, when the depth of repair is less than the radiographic sensitivity required, re-radiography may be omitted.

NON-DESTRUCTIVE TESTING PROCEDURE

Index:

1.0 Welding process checkPag.19

1.1 Check of welding procedurePag. 19

2.0 Welders & welding operators qualification check Pag.20

2.1 Check of welders & welding operator qualificationPag.20

3.0 Ultrasonic testing specificationsPag.20

3.1 Technique for ultrasonic examination of welded jointsPag. 20

4.0 Radiographic examination specificationsPag.20

4.1 Radiographic examination 60 % of welded jointsPag.20

4.2 Radiation energyPag. 24

4.3 Geometrical unsharpened limitation guidelinesPag.25

4.4 Evaluation of radiographic qualityPag.25

4.5 DocumentationPag.26

4.6 Radiographic requirements for ASME Section VIII Code

Division 1 e 2 pressure vesselsPag.27

4.7 Acceptance criteria for spot radiography of Division 1 vessels onlyPag.28

4.8 Evaluation and re-examinationPag. 29

5.0 Visual inspection requirementPag.29

5.1 Visual inspection technique procedure standard techniquePag.29

5.2 Visual inspection requirements for ASME Section VIII Code

Division 1 & 2 pressure vesselsPag.29

6.0 Marking & ReportsPag.31

6.1 General marking and reportsPag.31

6.2 Placement of location markers (film interval numbers or

identification numbers) and film identificationPag.32

7.0 Hydropressure testingPag.33

7.1 Hydrostatic test for underground piping Pag.33

7.2 Final hydraulic testPag.33

1.0 Welding process check

The Inspector shall review the welding procedures specifications (WPS) to be used in addition to the contract specified codes and specifications.

2.0 Welders & welding operators qualification check

2.1 Check of welder and welding operator qualifications

a)The Manufacturer shall certify that the welding on a vessel has been done only by welders and welding operators who have been qualified under the requirements of Section IX and the Inspector shall assure himself that only qualified welders and welding operators have been used.

b)The Manufacturer shall make available to the Inspector a certified copy of the record of the qualification tests of each welder and welding operator. The Inspector shall have the right at any time to call for a witness tests of the welding procedure or of' the ability of any welder and welding operator.

3.0 Ultrasonic testing specifications

3.1 Technique for ultrasonic examination of welded joints

Ultrasonic 100% examination of welded joints, shall be performed in accordance with attached Appendix and shall be evaluated to the acceptance standards specified. The written examination procedure shall be available to the Inspector and shall he proven by actual demonstration to the satisfaction of the Inspector to be capable of detecting and locating imperfections described in this Division.

3.1.1 Ultrasonic examination of welds

Scope

This Appendix describes methods which shall be employed when ultrasonic examination of welds specified in this Division.

Ultrasonic examination shall be performed in accordance with a written procedure, certified by the Manufacturer to he in accordance with the requirements of T150 of Section V.

Certification of competence of nondestructive examiner

The Manufacturer shall certify that personnel performing and evaluating ultrasonic examinations required by this Division are qualified. SNTTC-1A shall be used as a guideline for employers to establish their written practice for qualification of their personnel. Provisions for training, experience, and qualification of NDE personnel shall be described in the Manufacturers Quality Control System.

Acceptance rejection standards

These Standards shall apply unless other standards are specified for specific applications within this Division.

Imperfections which produce a response greater than 20% of the reference level shall be investigated to the extent that the operator can determine the shape, identity, and location of all such imperfections and evaluate them in terms of the acceptance standards given in (a) and (b) below.

a)Indications characterized as cracks, lack of fusion, or incomplete penetration are unacceptable regardless of length.

b)Other imperfections are unacceptable if the indications exceed the reference level amplitude.

Report of examination

The Manufacturer shall prepare a report of the ultrasonic examination and a copy of this report shall he retained by the Manufacturer until the Manufacturer's Data Report has been signed by the inspector. The report shall contain the information required by Section V. In addition, a record of repaired areas shall he noted as well as the results of the reexamination of the repaired areas. The Manufacturer shall also maintain a record of all reflections from uncorrected areas having responses that exceed 50% of the reference level. This record shall locate each area, the response level, the dimensions, the depth below the surface, and the classification.

4.0 Radiographic examination specification

4.1 Radiographic examination of welded joints (15% pipe factory and 60% pipeline)a)All welded joints to be radiographed shall be examined in accordance as per attached specifications

1)A complete set of radiographs and records, maintained.

2)The personnel performing and evaluating radiographic examinations required by this Division are qualified and certified in accordance with procedures.

3) Final acceptance of radiographs shall be based on the ability to see the prescribed penetrameter image and the specified hole or the designated wire of a wire penetrameter.

4) Recommended Practice No. SNT-TC-IA, Personnel Qualification and Certification in Nondestructive Testing, is published by the American Society for Nondestructive Testing Inc. 1711 Arlingate Plaza, Caller #28518, Columbus, Ohio 43.

b)

Indications shown on the radiographs of welds and characterized as imperfections are unacceptable under the following conditions and shall be repaired, and the repair radiographed, ultrasonically examined in accordance with the method and the standards specified, provided the defect has been confirmed by the ultrasonic examination to the satisfaction of the Authorized Inspector prior to making the repair. For material thickness in excess of 1 in., the concurrence of the user shall be obtained. This ultrasonic examination shall be noted under remarks on the Manufacturer's Data Report Form:

1) any indication characterized as a crack or zone of incomplete fusion or penetration;

2) any other elongated indication on the radiograph which has length greater than:

(a) 1/4 in. for t up to 3/4 in.

(b) 1/3 in. for t from 3/4 in. to 2 1/4 in.

(c)3/4 in. for t over 2 1/4 in.

where t= the thickness of the weld excluding any allowable reinforcement. For a butt weld joining two members having different thickness at the weld, t is the thinner of these two thickness. If a full penetration weld includes a fillet weld, the thickness of the throat of the fillet shall be included in t.

3)any group of aligned indications that have an aggregate length greater than t in a length of 12t, except when the distance between the successive imperfections exceeds 6L where L is the length of the longest imperfection in the group;

4)rounded indications in excess of that specified by the acceptance standards.

c)All welded joints to be examined by Real Time Radioscopic Examination shall be examined in accordance with Specifications.

1)A complete set of records shall be evaluated by the Manufacturer prior to being presented to the Inspector. Imperfections shall be repaired and the repair reexamined by either film or Real Time Radioscopic Examination. Records shall be retained until the Data Report has been signed by the Inspector.

2)Provisions for training, experience, qualification and certification of personnel responsible for equipment setup, calibration, operation, and evaluation of examination data shall be described in the Manufacturer's Quality Control System.

3)The use of Real Time Radioscopic Examination shall be noted under remarks on the Manufacturer's Data Report.

4.1.2 ASME section v code article 2

Scope

This General Radiographic Examination technique procedure contains the requirements of Article 2 of the ASME Section V Code and is to be used with the procedure for the applicable referencing Code or Standard.

This examination method shall be used to inspect steel, nickel and aluminum welds in the thickness range from 1/6 inch (3.2 mm) to 14 inches (356 mm).

Reference

1995 ASME Section V Code, Article 2, with the following Addenda: 96.

Equipment and materials

As per attached RX Procedures (English version will be submitted as soon as possible)

4.1.3 Technique for radiographic examination

Prepare weld surfaces by removing weld surface irregularities on both sides (where accessible) by any suitable process to such a degree that the resulting radiographic image due to any irregularities can not mask or be confused with the image of any discontinuity. The finished surface of all butt welded joints may be flush with the base material or may have reasonably uniform crowns.

IQI Selection (See table at the end of section)

-For weld without reinforcement, the thickness on which the penetrameter is based is the nominal single wall thickness. This is the weld thickness. Back-up bars, backing rings or backing strips are not to be considered as part of the weld thickness

-For we1ds with reinforcement, the thickness on which the penetrameter is based is the nominal single wall thickness plus the estimated weld reinforcement. 'This is the weld thickness and includes the estimated weld reinforcement on both sides. Back-up bars, backing rings or backing strips are not to be considered as part of the weld or reinforcement thickness.

-When the weld metal is of an alloy group or grade which has a radiation attenuation that differs from the base material, the penetrameter material selection shall be based on the weld metal or shall be from an alloy material group or grade with less radiation absorption than the material being radiographed. As an example, for Inconel weld metal use of a carbon steel or stainless steel IQI is acceptable

-When density limits can not be met with one penetrameter and the exceptional density area(s) is at the interface of the weld meta1 and the base material, the materia1 se1ection for the additional penetrameter(s) shall be based on the base material.

IQI Placement

-For single or double wall exposures for single wall viewing, place a source side penetrameter on the side nearest the radiation source. Where inaccessibility prevents this, place a film side penetrameter in contact with the object being examined. Place a lead letter F" adjacent to or on the penetrameter (s) , but it sha11 not mask the essential hole or designated wire.

-For double wall exposures for double wall viewing, place a source side penetrameter on the side nearest the radiation source.

-When using hole type penetrameters, place then adjacent to or on the weld. If the filler metal is not radiographically similar to the base material (as categories in SE1025), place the hole type penetrameter on the weld. When using wire type penetrameters, place them on the weld with the wires perpendicular to the length of the weld. The lead identification numbers for either type penetrameter shall not appear in the area of interest

-Lead identification numbers and lead letter F when used, may appear in the area of interest; if geometric configuration makes it impractical to place the penetrameter.

4.1.4 Number of IQIs

Use at least one penetrameter for each exposure

An additional penetrameter may be used to meet the required density variation limits.

When one or more than one film holder or cassette is used for a single exposure, a penetrameter image shall appear on each radiograph, except for the following conditions:

1 For cylindrical components where the source is placed on the axis of the component for a single exposure, at least three penetrameters, spaced approximately 120 deg. Apart, are required under the following conditions:

a) when the complete circumference is radiographed using one or more film holders, or;

b) when a section or sections of the circumference, where the length between the ends of the outermost sections span 240 or more deg., is radiographed using one or more film holders. Additional film locations may be required to obtain necessary penetrameter spacing.

2 For cylindrical components where the source is placed on the axis of the component for a single exposure, at least three penetrameters, with one placed at each end of the span of the circumference radiographed and one in the approximate center of the span, are required under the following conditions:

a) when a section of the circumference, the length of which is greater than 120 deg. And less than 240 deg., is radiographed using just one film holder, or;

b) when a section or sections of the circumference, where the length between the ends of the outermost sections span less than 240 deg., is radiographed using more than one film holder.

3 In (1) and (2) above, where sections of longitudinal welds adjoining the circumferential weld are radiographed simultaneously with the cricumferential weld, an additional penetrameter shall be placed on each longitudinal weld at the end of the section most remote from the junction with the circumferential weld being radiographed.

4 For spherical components where the source is placed at the center of the component for a single exposure, at least three penetrameters, spaced approximately 120 dec. Apart, are required under the following conditions:

a) when a complete circumference is radiographed using one or more film holders, or;

b) when a section or sections of a circumference, where the length between the ends of the outermost sections span 240 or more deg., is radiographed using one or more film holders. Additional film locations may be required to obtain necessary penetrameter spacing.

5 For spherical components where the source is placed at the center of the component for a single exposure, at least three penetrameter, with one placed at each end of the radiographed span of the circumference radiographed and one in the approximate center of the span, are required under the following conditions:

a) when a section of a circumference, the length of which is greater than 120 deg. And less than 240 deg., is radiographed using just one film holder, or;

b) when a section or sections of a circumference, where the length between the ends of the outermost sections span less than 240 deg., is radiographed using more than one film holder.

6 In (4) and (5) above, where other welds are radiographed simultaneously with the circumferential weld, one additional penetrameter shall be placed on each other weld.

7 When an array of components in a circle is radiographed, at least one penetrameter shall show on each component image

8 In order to maintain the continu8iti of records involving subsequent exposure, all radiographs exhibiting penetrameters which qualify the techniques permitted in accordance with (1) through (6) above shall be retained.

4.1.5 Shimming Hole Type Penetrameters

If the weld reinforcement and/or backing strip are not removed, if needed, place a shim of radio-graphically similar material to the weld metal under the hole type penetrameter so that the density throughout the area of interest meets the density limits.

Shim size, if needed, shall exceed the hole type penetrameter dimension such that the outline of at least three sides of the penetrameter image through the shim are visible in the radiograph.

4.1.6 Blocking and Masking Technique

Use filters, if necessary, to improve the quality of the radiograph

A lead symbol 3, with minimum dimensions of inch (12.7 mm) in height and 1/16 inch (1.6 mm) in thickness, shall be attached to the back of each film holder during exposure. If a light image of the B appears on a darker background of the radiograph, protection form backscatter is insufficient and the radiograph shall be considered unacceptable. A dark image of the B on a lighter background is not cause for rejection.

4.1.7 Length of Film

For 100% radiographic examination, the length of film used will be determined by the job conditions. However, film length shall be at least 1 inch (25 mm) greater than the interval spacing to ensure adequate overlap at each end.

For spot radiographic examination, the minimum length of film shall be 7 inches (178 mm).

4.1.8 Shape of film

Shape of the film to the contour of the object and place it as close as possible to the surface of the weld during exposure.

4.1.9 Number of Exposures

4.1.9.1The number of spot radiographs and their locations shall be in accordance with drawings and instructions.

4.1.9.2For the Single Wall Technique, when the source is located on the inside or outside of the vessel or pipe, an adequate number of exposures shall be made to demonstrate coverage.

4.1.9.3For the Double Wall Technique for Single Wall Viewing, a minimum of three (3) exposures separated by 120 is required.

4.1.9.4 For the Double Wall Technique for Double Wall Viewing, (3 inch (89 mm) O.D. pipe or less), the following applies:

1) A minimum of two (2) exposures are required, taken at 90 to each other, when the radiation beam is offset from the plane of the weld centerline at an angle sufficient to separate the images of the weld so there is no overlap of areas to be interpreted. See Figure C.

2) A minimum of three (3) exposures are required, taken at 60 to 120 to each other, when the radiation beam is positioned so the images of both walls are superimposed.

4.2 Radiation energy

4.2.1 X-radiation

The radiographic technique shall demonstrate that the required radiographic sensitivity has been obtained.

4.2.2 Gamma Radiation

42.2.1The minimum thickness of steel or nickel for which radioactive Iridium 192 may be used shall be 0.75 inches (19 mm) and for Cobalt 60 shall be 1.50 inches (38 mm) except al provided in 6.3

4.2.2.2. Radioactive isotopes shall not be used on aluminum with a minimum thickness less than 2.50 inches (63.5 mm)

4.2.3

The maximum thickness for the use of radioactive isotopes is primarily dictated by exposure time; therefore, upper limits are not shown. The minimum recommended thickness limitation may be reduced when the radiographic techniques used demonstrate that the required radiographic sensitivity has been obtained.

4.3 Geometrical unsharpened limitation guidelines

The following geometrical unsharpened values shall be used as a guide for determining minimum source to weld or object distant (D). Final acceptance of radiographs shall be based on the ability to see the prescribed penetrameter image and specified hole or the designated wire of a wire penetramenter.

MaterialUg

Thickness, inches (mm)Maximum inches (mm)

Under 2 (51)0.020 (0..5)

2 (51) through 3 (75)0.030 (0.76)

Over 3 (76) through 3 (102)0.040 (1.0)

Greater than 4 (102)0.070 (1.8)

Geometrical unsharpened (Ug), equals effective source size (F): the maximum projected dimension of the radiating source in the plane perpendicular to the distance D from the weld or object being radiographed, times the distance (d) from source side of weld or object being radiographed to the film, over distance (D) form source of radiation to weld or object being radiographed.

UG = Fd/D

4.4 Evaluation of radiographic quality

Evaluate the radiographic quality by the image of a properly located IQI and the following film quality requirements:

4.4.1 The images of the identifying numbers and the following as applicable.

1 Hole Type Penetrameters

a) Penetrameter Outline

b) Specified Essential Hole

2 Wire Type Penetrameters

a) Designated Wire

4.4.2 The film density through the image of the body of a hole type penetrameter or adjacent to the designated wire of a wire type penetrameter and the area of interest for single film viewing shall be 1.8 minimum for radiographs made with an X-ray source and 2.0 minimum for radiographs made with a gamma ray source. For composite viewing of multiple film exposures, each film of the composite set shall have a minimum density of 1.3. The maximum density shall be 4.0 for viewing. A tolerance of 0.05 in density is allowed for variations between densitometer readings.

4.4.3 Each penetrameter shall represent an area of essentially uniform radiographic density as judged by a calibrated density comparison strip or densitometer. If the film density through the area of interest, varies by more than minus 15 or plus 30 percent from the density through the body of the hole type penetrameter or adjacent to the designated wire of a wire type penetramenter, then an additional penetramenter is required for the exceptional area or areas.

When shims are used, the thirty (30) percent density restriction may be exceeded, provided the hole type penetrameter required sensitivity is displayed and the density limitations are not exceeded.

4.4.4 If the requirements are met by using two Penetrameters, one shall be representative of the lightest area of interest and the other the darkest are of interest, and the intervening densities on the radiograph shall be considered as having acceptable density.

4.4.5 All radiographs shall be free from mechanical, chemical or other processing defects that could interfere with proper interpretation of the radiograph.

4.5 Documentation

Record radiographs, with their grading, on a Report of Radiography Examination

4.5.1.1 Record spot radiography and 100% radiography on separate report forms.

4.5.1.2Acceptable radiographs may be combined on one line of the report, provided the interval numbers are consecutive.

4.5.1.3 List tracers separately in sequence and mark them T1, T2, etc.

4.5.1.4 List repairs separately in sequence and mark them R1, R2, etc.

4.5.1.5 List reshots, taken for reason other than either of the above, separately from the original film and mark them RS.

4.5.1.6 When inaccessibility or other limitations prevent the location of markers, a dimensioned sketch of the geometric arrangement including marker locations shall be documented on the back of the Report of Radiography Examination form.

4.5.2 The following radiographs need not be retained or recorded.

4.5.2.1 In-Process Radiographs taken for information only on an area of a joint not fully welded regardless of whether or not they are used for making repairs.

4.5.2.2 Technique radiographs showing no rejectable indications taken to establish parameters that produce radiographs that meet the film quality requirements of this procedure.

4.5.2.3 Radiographs showing no rejectable indications, but unacceptable from standpoint of film quality requirements due to defective film, improper processing, physical damage, or improper technique.

4.5.2.4 Radiographs that can not be identified as to location (i.e. vessel, joint number, film number)

4.5.2.5 Record on the Record Drawing or Checklist the film interval or identification numbers and the sequential direction of the numbers for each weld joint as follows:

4.5.2.6 For 100% or Random Radiography, record the first and last interval number

4.5.2.7 For Spot Radiography, record all the film identification numbers.

4.5.2.8 Record joint identification number

4.5.2.9 Record welders or operators identification for all butt welded joints.

4.6 Radiographic requirements for ASME Section VIII Code Division 1 e 2 pressure vessels

Scope

This procedure contains the ASME Section VIII Code radiographic acceptance criteria requirements and is to be used with the applicable standard or contract X or N general Radiographic Examination Technique Procedure RT5 or RTDF.

Reference

1992 ASME Section VIII Code or with any of the following Addenda: 92, 93, 94

1995 ASME Section VIII Code or with any of the following Addenda: 95, 96

Personnel

Personnel performing this examination shall be qualified in accordance with a Nondestructive Examination Personnel Training, Qualification and certification Program which is in accordance with the guidelines of the Code referenced edition of SNT-TC-1A. Level I, II or III personnel may perform radiography and level II or III personnel shall evaluate.

Reinforcement

Reinforcement on each side of all butt welded joints shall not exceed the following thickness:

Nominal WallMaximum Reinforcement, I (mm)

Thickness (T), In. (mm)Circumferential JointsOther

In pipe and tubingWelds

Division 1Division 2Div. 1 & 2

Less than 3/32(2.4)3/32(2.4)3/32(2.4)1/32(0.8)

3/32 to 3/16(2.4 to 4.8) incl.1/8(3.2)3/32(2.4)1/16(1.6)

Over 3/16 to (4.8 to 12.7), incl.5/32(4.0)1/8(3.2)3/32(2.4)

Over to 1(12.7 to 25.4) incl.1/8(3.0)5/32(4.0)3/32(2.4)

Over 1 to 2 (25.4 to 51) incl.1/8(3.0)5/32(4.0)1/8(3.2)

Over 2 to 3(51 to 75) incl.1/4 (6.4)5/32(4.0)5/32(4.0)

Over 3 to 4(76 to 102) incl.1/4 (6.4)5/32(4.0)7/32(5.6)

Over 4 to 5(102 to 127) incl.1/4 (6.4)1/4(6.4)1/4(6.4)

Over 5 (127)5/16 (7.9)5/16(7.9)5/15(7.9)

Weld length shown in spot radiographs

- Each radiograph shall clearly show a minimum of 6 inches (152 mm) of weld length.

- In addition all four-way junction radiographs shall clearly show not less than four (4) inches (102 mm) of longitudinal weld length on each side of the circumferential weld. A junction is considered a four-way when the course stagger is 5T or less. T equals the thickness of the thicker plate.

Evaluation of indication

-All relevant indication shall be evaluated in terms of the Acceptance Criteria in this procedure.

-Relevant indications not characterized as being a crack or zone of incomplete fusion or penetration shall be evaluated as being:

Elongated indications if their length is more than three (3) times the width

Rounded indications if their length is equal to or less than three (3) times the width

Acceptance criteria for 100% radiography of division 1 vessels and all radiography (100% and spot) of division 2 vessels

Sections of welds that are shown by radiography to have any of the following types of discontinuities are unacceptable. The weld shall be repaired and re-radiographed in accordance with this procedure.

- Any indication characterized as a crack or zone of incomplete fusion or penetration.

- Any other elongated indication which has a length greater then:

1/4 in. (6.3 mm) for T up to 3/4 in. (19 mm)

1/3 T for T from 3/4 in. (19 mm) to 2-1/4 in. (57 mm)

3/4 in. (19 mm) for T over 2-1/4 in. (57 mm)

T = the thickness of the weld excluding any allowable reinforcement. For a butt weld joining two members having different thickness at the weld, T is the thinner of these two thickness. If a full penetration weld includes a fillet weld, the thickness of the throat of the fillet shall be included in T.

-Any group of aligned indications that have an aggregate length greater than T in a length of 12 T, except where the distance between successive imperfections exceeds 6L, where L is the length of the longest imperfections in the group.

-Rounded indications in excess of that shown as acceptable in Appendix 4 of Division 1 or in Appendix 8 of Division 2 of the ASME Section VIII Code.

4.7 Acceptance criteria for spot radiography of Division 1 vessels only

4.7.1Welds in which the radiography shows any of the following types of discontinuities are unacceptable until repaired and re-radiographed per this procedure:

4.7.1.1 Any indication characterized as a crack or zone of incomplete fusion or penetration.

4.7.1.2 Indications characterized as slag inclusions or cavities which have a length greater than 2/3T where T is the thickness of the weld excluding any allowable reinforcement. For a butt weld joining two members having different thickness at the weld, T is the thinner of these two thickness. If a full penetration weld includes a fillet weld, the thickness of the throat of the fillet shall be included in T. Maximum length of any such indication shall be inch (19 mm). Any such indication shorter than inch (6 mm) shall be acceptable for any plate thickness.

4.7.2If several indications within the above limitations exist in line, the weld shall be acceptable if the sum of the longest dimensions of all such indications is no more than T in a length of 6T (or proportionately for radiographs shorter than 6T) and if the longest indications considered are separated by at least 3L of acceptable weld metal, where L is the length of the longest indication.

4.7.3 Rounded indications are not a factor in the acceptability of welds required to be spot radiographed.

4.8 Evaluation and re-examination

4.8.1When a spot radiograph is graded acceptable the entire length of weld represented by this radiograph is acceptable.

4.8.2When a spot radiograph discloses welding which does not comply with the minimum requirements two additional radiographs (tracers) shall be taken in the same weld unit at locations away from the original spot.

4.8.2.1If the two additional radiographs (tracers) show welding which meets the minimum quality requirements the entire weld unit represented by the three radiographs is acceptable. The unacceptable welding disclosed by the first of the three radiographs shall be removed and the area repaired and re-radiographed.

4.8.2.2 If either of the two additional radiographs (tracers) shows unacceptable welding, the entire unit of weld represented shall be rejected. At the option of the Manufacturer:

EITHER

The entire unit of rejected weld shall be removed, the joint rewelded and spot radiographed in accordance with this procedure.

OR

The entire unit of rejected weld shall be 100% radiographed and only unacceptable welding need be repaired and spot radiographed in accordance with this procedure.

5.0 Visual inspection requirement

The rules in the following paragraphs apply specifically to the inspection and testing of pressure vessels and vessel parts that are fabricated by welding and shall be used in conjunction with the general requirements for Inspection and Tests and with the specific requirements for Inspection and Tests that pertain to the class of material used.

5.1 Visual inspection technique procedure standard technique

Scope

This general visual inspection technique procedure is to be used with the procedure for the applicable referencing Code or Standard.

Personnel

Experienced personnel shall perform the inspections outlined in this procedure.

Equipment

- Fillet weld gauges, weld reinforcement gauges and measuring tapes

- Two cell (C or D) flashlight or brighter light source

- Wire brushes and /or Grinding Wheels for stainless steel and nickel base alloy material, use wheels and 300 Series stainless brushes that have not been previously used on carbon or low alloys steels.

- If necessary, cleaning agents such as isopropyl alcohol, Tri-sodium phosphate, double-check DR-60 or equal.

NOTE:When examining nickel base alloys or austenitic stainless steels, all materials, including penetrants, solvents or cleaning agents, developers, etc. shall be analyzed individually for residual total sulfur, chlorine and fluorine content in accordance with Section V, Article 6, Paragraph T-641. For nickel base alloys, the residual total sulfur content shall not exceed one (1) percent by weight. For austenitic stainless steels, the residual total chlorine and fluorine content shall not exceed one (1) percent by weight or by D808 the residue total shall not exceed 1% by weight. Certification of test results for each material, including batch number, if applicable shall obtain. Cleaning solvents and agents purchased with known chemical composition do not require analysis.

-If necessary, visual aids, such as mirrors, magnifying lenses etc.

Procedure

Prepare and clean the weld surface to be inspected.

-Remove weld spatter, slag and flux with descaling tools, wire brushes, grinding wheels or other suitable means. Use stainless wire brushes when brushing austenitic or nickel base alloy material.

-As necessary, clean welds of dirt, oil, grease or other substances that might interfere with the examination using a cleaning agent.

-While performing the inspection, natural or artificial lighting shall be adequate to illuminate the surface being examined to a minimum of fifty (50) foot cans. Illumination form any one of the following light sources or a brighter light source is adequate:

Light Source2D Cell60 Watt75 Watt100 Watt

FlashlightBulbBulbBulb

Maximum Source to Object

Distance in inches (mm)10 (254)10 (254)13 (381)18 (457)

-If possible, the surface being inspected shall be viewed without visual aids. However, visual aids such as mirrors, magnifying lenses, etc. may be used if access to the surface being examined is not easily achieved.

-Personnel performing direct visual inspections shall have access sufficient to place the eye within 24 inches (610 mm) of the surface to be inspected and at an angle not less than 30 degrees to the surface to be inspected. If the use of visual aids is required, the resolution capability shall be at least equivalent to that obtainable by direct visual observation.

This may be demonstrated by the inspector being able to see a fine line, 1/32 inch (.8 mm) wide or less, or other artificial flaw on the surface (or a surface similar to that being examined) in the least discernible (viewable) location of the area being examined).

-If required by the applicable Code or Standard, inspect joints after fit-up, but before welding, for correct weld edge prep, gap and alignment.

-After welding, inspect welds for surface indications and appearance and measure at representative locations for adequacy of size, concavity, convexity (if applicable), reinforcement and length using gauges and measuring tapes.

-Where readily accessible for viewing without visual aids, inspect the root surface of single sided welds to determine the amount of penetration (protusion) or concavity (suck up).

5.2 Visual inspection requirements for ASME Section VIII Code division 1 & 2 pressure vessels

Scope

This procedure contains the ASME Section VIII Code visual inspection acceptance criteria requirements for complete welds and is to be used with the applicable standard or contract X or N general Visual Inspection Technique Procedure VI5.

Reference

1992 ASME Section VIII Code or with any of the following Addenda: 92, 93, 94

1995 ASME Section VIII Code or with any of the following Addenda: 95, 96

Acceptance Criteria

-As welded surfaces are permitted, provided the surface of welds are sufficiently free from coarse ripples, grooves, overlaps, and abrupt ridges and valleys.

-The surface condition of the finished weld shall be suitable for proper interpretation of radiographic and other required nondestructive examinations when these examinations are required by contract drawings.

-Undercut shall not exceed 1/32 inch (0.8 mm) or 10% of the nominal thickness of the adjoining surface, whichever is less.

-The surface of butt welded joints may be flush with the base material or may have uniform crowns. The height of reinforcement for each weld surface shall not exceed the following:

Nominal WallMaximum Reinforcement, I (mm)

Thickness (T), In. (mm)Circumferential JointsOther

In pipe and tubingWelds

Division 1Division 2Div. 1 & 2

Less than 3/32(2.4)3/32(2.4)3/32(2.4)1/32(0.8)

3/32 to 3/16(2.4 to 4.8) incl.1/8(3.2)3/32(2.4)1/16(1.6)

Over 3/16 to (4.8 to 12.7), incl.5/32(4.0)1/8(3.2)3/32(2.4)

Over to 1(12.7 to 25.4) incl.1/8(3.0)5/32(4.0)3/32(2.4)

Over 1 to 2 (25.4 to 51) incl.1/8(3.0)5/32(4.0)1/8(3.2)

Over 2 to 3(51 to 75) incl.1/4 (6.4)5/32(4.0)5/32(4.0)

Over 3 to 4(76 to 102) incl.1/4 (6.4)5/32(4.0)7/32(5.6)

Over 4 to 5(102 to 127) incl.1/4 (6.4)1/4(6.4)1/4(6.4)

Over 5 (127)5/16 (7.9)5/16(7.9)5/15(7.9)

-Concavity on the root side of a single side welded circumferential butt weld is permitted when the resulting thickness of the weld is at least equal to the thickness of the thinner member of the two (2) sections being joined and the contour of the concavity is smooth.

-Offset of final butt welded joints shall not be greater than that shown in the following Table

NOTE:t is the nominal thickness of the thinner section of the joint.

Section Thickness, in. (mm)Joint Categories

AB,C, & D

Up to 1/2 (12.7), incl.1/4 t1/4 t

Over to (12.7 to 19), incl.1/8 in. (3.2) t

Over to 1-1/2 (19 to 38), incl.1/8 in. (3.2)3/16 in. (4.8)

Over 1-1/2 to 2 (38 to 51)1/8 in. (3.2)1/8 t

Over 2 (51)Lesser ofLesser of

1/16t or 3/8 in. (9.5)1/8t or in. (19)

-Any offset within the allowable tolerance of the Table shall be faired at a three to one taper over the width of the finished weld, or if necessary, by adding additional weld metal beyond what would otherwise be the edge of the weld.

-Fillet Welds

Fillet welds may vary from convex to concave

The size of the fillet weld shall be determined as follows:

-Cracks or other linear indications in welds are unacceptable.

6.0 Marking & Reports

6.1 General marking and reports

The provisions for marking and reports, UG115 through UG120, shall apply without supplement to welded pressure vessels.

6.2 Placement of location markers (film interval numbers or identification numbers) and film identification

Place location markers, which are to appear as images on the film, on the surface near the weld ate the film intervals for multiple exposures or the approximate center point of the film location for single exposures. The location of the markers shall be marked permanently on the surface of the part when permitted (shall be with a low stress centerpunch) or on a record drawing. In this manner, the area of interest on a radiograph may be accurately traceable to its location on the surface of the part. It also provides evidence on the radiograph that the area being examined has been obtained, When permanent marking is not allowed, use temporary marking such as a paint stick or equal.

6.2.1Lead number location markers (film interval numbers or identification numbers), which are to appear as images on the film, shall be placed on the material adjacent to the weld at the marks located in 5.1 and as follows:

6.2.2Location markers shall be placed on the source side when radiographing joints in:

-Flat components or longitudinal joints in cylindrical or conical components;

-Curved or spherical components whose concave side is toward the source and when the source to material distance is less than the inside radius of the component;

-Curved or spherical components whose convex side is toward the source.

6.2.3Location markers shall be placed on the film side when radiographing joints in curved or spherical components whose concave side is toward the source and when the source to material distance is greater than the inside radius.

6.2.4Location markers may be placed on either the source side or film side when radiographing joints in curved or spherical components whose concave side is toward the source and the source to material distance equal the inside radius of the component.

6.2.5As an alternative to source side placement, location markers may be placed on the film side when the radiograph shows coverage beyond the location markers to the extent demonstrated as follows:

6.2.6Markers for pipe welds shall be lead numbers as follows:6.2.7For single wall viewing, circumferential number tapes shall be used. The 0 numbers shall be placed on the 0 point on the pipe and the remaining numbers located clockwise (or counter-clockwise) around the outside of the pipe. A minimum number of markers shall be used to provide evidence that the required coverage has been obtained.

6.2.8For double wall viewing, at least one location marker shall be placed on the source side surface adjacent to the weld for each exposure.

6.2.9Permanently mark each film with the following information:

Contract Number

Pipe Line Identification

Joint identification number

Film interval numbers or identification numbers

Re-shot, repair shot or tracer shot identification (RS, R1, T1, Etc,)

Manufacturers name or symbol

Welder or operators identification (if not on check list or record drawing)

Date of the Radiograph

7.0 Hydropressure testing

7.1 Hydrostatic test for underground piping

As indicated in Erection procedure (page 7):

7.1.1For the pipes, the pressure shall first be gradually brought to the testing value, later shall be lowered to the calculated value and maintained for the time needed to allow, where possible, visual control of the welding; shall then be brought to test value and maintained with this value for at least 10 minutes, and anyhow for the time needed in order to make a careful exam of all the welded joints and expansion joints that may need tightened.

7.1.2 If the hydraulic test reveals unacceptable local deformation or transuding for lack of penetration, scoring, cracks, porosity or other, the faulty element shall be repaired and re-examined.

7.1.3 The pressure, during the hydraulic test shall be recorded continually with a manometer.

7.2 Final hydraulic test

7.2.1 Test methods

7.2.1.1After the completion of erection, and an accurate internal control of the piping in order to ensure that no extraneous materials remained inside, the pipes shall be submitted, before starting, to the static tests of hydraulic pressure.

7.2.1.2 For the tests execution, the downstream cut-off may be carried out with the machine valves when the seal is already checked and the relative base foundations verified also for the loads resulting from the tests; when these conditions are not respected, flanged bottoms shall be used, the piping shall be filled with water through the bottoms with pump connections, the air discharge and the manometer. Safety valves shall be gagged, provisions shall be made to limit maximum pressure applied during test.

7.2.1.3 The piping shall be filled with water and maintained for the required length of time to permit in services leak testing. All bolts of the expansion joints shall be adjusted.

7.2.1.4 If during tests appear seal defects, the defectous elements, if possible, shall be repaired in accordance to the specifications or a replace may be requested. The hydraulic test of the piping section where the defectous element was found shall be repeated.

7.2.1.5 The pressure shall be gradually brought to test value and so maintained for 30 minutes; then lowered to the value corresponding to maximum static level in the load chamber or in the piezometer well; at this pressure through visual control the junctions carried out during the site assembly shall be checked; at last the pressure shall be brought back to test value and maintained for the required time to carry out the piping inspection.

7.2.1.6 If during test appear resistance or seal defects, the defectous element, if possible, shall be repaired in accordance to the specification of paragraph 7.4 or a replacement may be requested.

The hydraulic test of the piping section where the defectous element was found shall be repeated.

PAINTING PROCEDURE

Index:

1.0 Field blasting & painting procedurePag.35

1.1 ScopePag.35

1.2 Surface preparationPag35

1.3 PaintingPag.35

Technical Data: Navitar ASPag.36

Technical Data: Jotabar ZEPPag.39

Technical Data: Primastic UniversalPag.42

2.0 Field Touch-Up RequirementsPag.45

3.0 Inspection RequirementsPag.45

4.0 General Painting requirementsPag.45

4.1 Paint bucketsPag.46

1.0 Field blasting & painting procedure

1.1 Scope

This procedure covers the material, surface preparation, coating system and general standard requirement for the Field cleaning, blasting and painting of the Penstocks. In areas, where Penstock will be buried (at power houses) the external coating shall be the same as internal coating.

1.2 Surface preparation

Internal and external will be sand blasted in accordance with the S.S. Grade 2-1/2, white metal.

1.3 Painting

Internal surface:two (2) coats of Epoxy coal-tar NAVITAR AS for a total thickness of dry film of 400 micros.

External surface: one (1) coat of Zinc-rich epoxy primer JOTABAR ZEP for a total thickness of dry film of 50 microns;

two (2) coats of high solids modified epoxy PRIMASTIC UNIVERSAL for a total thickness of dry film of 90 microns.

The total external surface will have a total dry film thickness of 140 microns.

NAVITAR AS

PRODUCT:Navitar ASDESCRIPTION: Navitar AS is 3 solventless, twopack epoxy coaltar coating which may be applied by ordinary airless spray in a high film thickness.

RECOMMENDED USE:Submerged steel structures, buried concrete or steel structures. Excellent protection against corrosion, Excellent in combination with cathodic protection.

TECHNICAL INFORMATION:

Colour:Dark Brown/Black

Solids (% by volume)::90 (2

Flash point : 75 C ( 2 (Setaflash)

Flexibility :Good

Gloss: Semiflat

Water resistance: Excellent

Chemical resistance: Good

Solvent resistance: Good (discoloration)

Abrasion resistance: Good

Application range typical :Film thickness per coatTheoretical spreading rate

in micronsm2/l

DryWet

200 400225 4454.5 2.3

3003303.0

APPLICATION DATA:

Application methods:Airless spray, Brush may be used for smaller areas

Miring ratio:2 parts Comp. A (base) to be mixed thoroughly with

(by volume):1 part Comp. B (curing agent)

Pot life (23 C):1 hour (Reduced at higher temp.)

Thinner/Cleaner:Jotun Thinner No. 17

Guiding data airless spray

Pressure at nozzle:20 MPa (20150 kp/cm2 2800 psi)

Nozzle tip:0.53 0.79 mm (0.0210.031")

Spray angle:4080

Filter:Check to ensure that filters are clean

NAVITAR AS (cont.)

SURFACE

PREPARATION:Clean dry and undamaged shopprimer or blast cleaning to Sa 2. (ISO 85011:1988/SS 05 5900). Power tool cleaning to min. St 2 (SIS 05 5900) may be acceptable for minor touchup work subject to exposure conditions.

CONDITION DURING

APPLICATION: The temperature of the substrate should be minimum 15 C and at least 3 C above the dew point of the air. The temperature and the relative humidity should be measured in the vicinity of the substrate. The temperature of the paint should be approx. 20 C at the time of application. If no heating unit is installed on the spray equipment, preheating in a waterbath to 20 C is recommended.

DRYING/

CURING TIME:The drying times are measured according to BS 3900 Part C2 and BS 3900 Part C3.

Drying times are generally related to air circulation, temperature, film thickness and number of coats, and will be affected correspondingly. The figures given in the table are typical with:

* Good ventilation

* Recommended film thickness

* One coat on top of inert substrate

Dry to recoat3

SubstrateSurface1Hard2CuredMinimumMaximum 4

temperatureDryDry

InteriorExterior

10 C24 h48 h14 d48 h-7 d

23C12 h24 h7 d24 h-7 d

35 C4 h6 h3 d6 h-4 d

1. Measured according to BS 3900 Part C2

2. Measured according to BS 3900 Part C3

3. Recommended data given far recoating with the same genetic type of paint.

4. The surface should be free from chalking and contamination prior to application. At interior exposure note that best intercoat adhesion occurs when the subsequent coat is applied before the preceding coat is cured. At exterior exposure the chalking effect especially from the sunlight limits the maximum dry to recoat time.

The given data must be considered as guidelines only. The actual drying time/times before recoating may be shorter or longer, depending on existing coating, generic type, film thickness, system chosen, no. of coats, ventilation, temperature, requirement for early handling and mechanical strength etc. A complete system can be described on a system sheet, where all parameters and special conditions could be included.

TYPICAL RECOMMENDED

PAINT SYSTEM:Navitar AS (diluted 25%) Stripe coat

Navitar AS1 x 300 m (Dry Film Thickness)

NAVITAR AS (cont.)

STORAGE AND PACKING:

STORAGE:The product most be stored in accordance with national regulations. Preferred storage conditions are to keep the containers in a dry space provided with adequate ventilation. The containers should be sealed tightly.

PACKING CONTENT:13 1 Comp. A (base) and 6.51 Comp. B (curing agent)

HEALTH AND SAFETY:Please observe the precautionary notices displayed on the container. Spray under well ventilated conditions. Do not breathe or inhale mist. Avoid skin contact. Spillage on the skin should immediately be removed with suitable cleanser, soap, and water, Eyes should be well flushed with water and medical attention sought immediately.

For detailed information on the health and safety hazards and precautions for use of this product, we refer to the Material Safety Data Sheet

DISCLAIMER:The information in this data sheet is given to the best of our knowledge based on laboratory testing and practical experience. However, as the product is often used under conditions beyond our control, we can not guarantee anything but the quality of the product itself. We reserve the right to change the given data without notice.

VERSION 1/97. ISSUED SEPTEMBER 1997, JOTUN FAINTS NORWAY

THIS DATA SUPERSEDES THOSE PREVIOUSLY ISSUES

JOTABAR ZEP

PRODUCT:JOTABAR ZEPDESCRIPTION: Jotabar ZEP is a twopack zinc-rich epoxy primer.

RECOMMENDED USE:As primer on blast cleaned steel. Jotabar ZEP is used in combination with most sophisticate coating systems to increase the durability

TECHNICAL INFORMATION:

Colour:Grey

Solids (% by volume)::43 ( 2

Flash point : 25 C ( 2 (Setaflash)

Flexibility :Good

Gloss: Flat

Water resistance: Excellent

Chemical resistance: Fair

Solvent resistance: Fair

Abrasion resistance: Good

Application range typical :Film thickness per coatTheoretical spreading rate

in micronsm2/l

DryWet

25 7560 17517.2 5.7

501158.6

APPLICATION DATA:

Application methods:Airless spray, Brush may be used for smaller areas

Miring ratio:2 parts Comp. A (base) to be mixed thoroughly with

(by volume):1 part Comp. B (curing agent)

Pot life (23 C):24 hours

Thinner/Cleaner:Jotun Thinner No. 17

Guiding data airless spray

Pressure at nozzle:15 MPa (150 kp/cm2 2100 psi)

Nozzle tip:0.38 0.53 mm (0.0150.021")

Spray angle:4080

Filter:Check to ensure that filters are clean

SURFACE

PREPARATION:Blast cleaning to Sa 2. (I