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Conoco-SP 880130SECTION 6 - CONSTRUCTION WELDING SPECIFICATION 6.2 6.3 SCOPE This specification applies to the welding of pipe, valves, flanges, fittings and other equipment for the installation of or modification to Company's facilities. Specifically excluded is welding of full-encirclement split repair sleeves, stopple connections, permanent branch connections and weld + end couplings to pressurized operating liquid filled pipelines. The standards of acceptability to be applied to welds tested destructively or non-destructively are also defined. The purpose of this specification is to define the minimum standards required for the production of high quality weldments. CODES AND STANDARDS As a minimum, all welding performed under this specification shall meet the requirements of the following codes and this specification. In the event of a conflict between D.O.T. Part 195 and any referenced material in this specification, the requirements of D.O.T. Part 195 shall prevail unless the requirements of the referenced material are more stringent, in which case the requirements of the referenced material shall govern. Department of Transportation, Title 49, Part 195, Transportation of Hazardous Liquids by Pipeline. ASME/ANSI 31.4, Liquid Transportation Systems for Hydrocarbons, Liquid Petroleum Gas, Anhydrous Ammonia, Alcohols, Most Recent Edition. and API Standard 1104, Standard for Welding Pipelines and Related Facilities 15th Edition, 1980. MATERIALS This specification shall apply to the welding of pipe, fitting valve and flange material listed in Exhibit E and conforming to: ~ API Specification 5L, API Specification For Line Pipe ASTM A105, Standard Specification For Steel Pipe Flanges & Flanged Fittings ASTM A105(F42), Standard Specification For Steel Pipe Flanges & Flanged Fittings ASTM A106 (Gr. B), Standard Specification For Seamless Carbon Steel Pipe For High Temperature Service. Page 2 6.4 6.5 6.6 ASTM A234-WPB (Y42)(Y52), Standard Specification For Piping Fittings of Wrought Carbon Steel & Alloy Steel For Moderate & Elevated Temperatures ASTM A694 (F52)(F60)(F65), Standard Specification For Forgings, Carbon & Alloy Steel, For Pipe Flanges, Fittings, Valves, & Parts For High-Pressure Transmission Service Materials with chemical andmechanical properties which comply with the above, even:though they are not manufactured in conformance with them. PROCESS Process shall be manual shielded metal arc welding (SMAW), gas metal arc welding (GMAW), a combination of these processes, or submerged arc welding (SAW). Automatic and semi-automatic processes may be used only upon specific prior approval by the Company. WELDING EQUIPMENT Contractor shall furnish all welding equipment and supplies required for the work. All equipment shall be in good working order and subject to approval by Company Representative. Equipment shall be maintained in good operating condition to ensure acceptable welds, avoid'-breakdowns, and protect the safety of personnel. Any equipment which does not meet the approval of the Company Representative or is incapable of producing satisfactory welds shall be removed from the job and replaced with acceptable equipment at Contractor's expense. WELDING MATERIALS AND SUPPLIES Ail welding materials and supplies shall be stored in a manner that will prevent damage from moisture or contamination from oil, grease or other deleterious elements. Coated electrodes, filler metals, shielding gases and fluxes shall be stored and handled in accordance with the manufacturer's recommended practice. Coated electrodes shall be stored in sealed original metal containers until ready for use. Those in opened containers shall be protected from deterioration and excessive moisture changes. Electrodes which show surface oxidation or fractured coatings shall be removed from the work site. Low hydrogen electrodes EXX18 and EXX18-1 when removed from sealed containers shall be stored in rod ovens at temperatures between 250 - 300 d~grees Fahrenheit. Any Dlectrode of 6.7 Page 3 low-hydrogen classification which has been exposed to the atmosphere for more than one hour shall be dried again as recommended by the manufacturer. Argon and carbon dioxide shielding gases shall be kept in the containers in which they are supplied, firmly anchored during storage and away from temperature extremes. Any welding materials or supplies which in the opinion of the Company Representative are damaged, contaminated or unsuitable for use shall be replaced with acceptable materials or supplies at the Contractor's expense. WELDING PROCEDURES Ail welding performed under this specification shall be performed in accordance with a Qualified Welding Procedure Specification. Contractor shall use Company's Qualified Welding Procedures (Attachment XXX) except that Contractor, at its option, may elect to qualify Alternate Welding Procedures. Alternate Welding Procedure qualification shall be in accordance with API 1104 and the requirements of this specification, including preparation of a written Welding Procedure Specification, welding of the test weld(s), and destructive testing of the test weld(s). All costs for preparation and qualification of Alternate Welding Procedures shall be born by Contractor. 6.7.1 ALTERNATE WELDING PROCEDURE QUALIFICATION Alternate Welding Procedure Specifications shall be established by Contractor then submitted to Company for approval at least two weeks prior to qualification testing. Contractor shall request from and use Company's "Welding Procedure Specification" forms for this purpose. An approved Alternate Welding Procedure Specification shall be qualified by joining two job sized pipe nipples following all details of the Procedure Specification as they will be applied to construction welding. Company may require more than one test weld for Alternate Welding Procedure Specifications with wide variable ranges. It is suggested that Contractor make several test welds to establish practical welding variable ranges before submitting final Alternate Welding Procedure Specification to Company for approval. All procedure weld tests,shall be conducted in the presence of a Company Representative. Page 4 6.8 6.9 6.10 Welding procedures which have been established, approved, and qualified shall not be changed in any way without approval of Company. Re-qualification may be required for any change. MATERIAL DEFECTS AND DAMAGE Contractor shall take precautions during all material handling operations to prevent damage to pipeline components including pipe, fittings, flanges, valves, and other items.~ Material containing surface defects or damage that may affect its strength or serviceability shall not be welded into the pipeline. These include: gouges, dents, buckles, laminations, split ends, hard spots, roll-ins, blisters, cracks, or other defects. The material containing the surface defect or damage shall be set aside for inspection and disposition by the Company Representative. If it is determined the defect or damage was not caused by Contractor's action then Contractor will be reimbursed for removing or correcting the defect or damage as directed by Company Representative. WEATHER CONDITIONS Welding shall not be done whenever the quality ~f a completed weld would be impaired by weather conditions such. as rain, snow, dew point, high winds, blowing sand or dust. During cold weather the interior of the pipe shall be free of snow or slush. The effects of cold weather can be minimized by the use of preheat and controlled cooling in accordance with this specification. The use of shelters, windshields or umbrellas may make conditions acceptable for welding. These protective devices, if used, should not be removed until the weldment has cooled enough to be touched by a bare hand. Pipe surfaces in the welding groove and vicinity shall remain dry until the weld is completed and has cooled to ambient temperature. The Company Representative shall decide if weather conditions are suitable for welding. WELDER QUALIFICATION 6.10.1 TESTING Each welder, and each welding unit and operator on automatic welding, shall pass a welder qualification test. Welders assigned to work in Oklahoma shall have a valid state certificate. All aspects of qualification shall meet the requirements of API Standard 1104, Sections 3.0 a~d 9.6 except the 6.10.2 6.10.3 6.10~4 Page 5 requirements of Section 6.10.7 of this specification shall be considered in addition to those of API 1104. Judgement as to failing or passing rests entirely with the Company Representative who will conduct the tests. His decision will be final and irrevocable. The welder shall use the same welding technique and proceed with the same speed he will use if he passes the test and is permitted to do production welding. Upon successful qualification the welder will be issued a "Welder Qualification" document by the Company which will identify those processes the welder is permitted to use. Unless otherwise excepted by Company, this qualification will remain valid for 6 months from date of test provided the necessary provisions of API 1104 are met and spot checks by the Company are satisfactory. At the option of the 'Company Representative, the welder may be qualified by radiographic inspection in lieu of the destructive tests. RETEST If, in the mutual opinion of the Company Representative and Contractor Representatives, failure of a welder to pass the test was a result of unavoidable conditions or conditions beyond welders' control, such a welder may be given a second opportunity to qualify. No further retest shall be permitted. EQUIPMENT AND SUPPLIES The Contractor shall furnish all equipment and supplies required for the test, including a tensile testing machine capable of measuring the load at which a tensile specimen fails. The machine should be equipped with a 1-3/4 inch plunger for guided bend tests. The Company shall furnish the Contractor joints of pipe for the purpose of making test nipples. Contractor shall furnish certification of the accuracy of the tensile test machine. Certification shall be .by an independent testing company and conducted within nine months of the contract award date. .WELDING OF TEST JOINT - BUTT JOINT Two job size pipe nipples shall be joined by following the details listed in the Qualified Welding Procedure Specification(s). The Company Representative will Page 6 6.10.5 6.10.6 6.10.7 decide whether the butt joint will be in a fixed horizontal or vertical plane or inclined at some angle. Normally the test will be in the fixed horizontal position or inclined at some angle less than 30 degrees. The test weld for an operator of automatic welding shall be in a fixed horizontal position. The welder should be given enough time to adjust the current on the welding machine by welding beads on scrap steel. VISUAL INSPECTION OF TEST WELDS - BU'l'l' JOINT The Company Representative shall inspect the progress of a welder or welding operator during welding of the test weld. The speed of welding should approximate the speed of a construction weld. The weld shall meet all the visual examination requirements for acceptance criteria prescribed by API 1104. The size, shape and contour of the root and cover beads shall show good workmanship. Failure to meet the above-noted shall be cause to disqualify the welder. No additional testing is necessary. TEST SPECIMENS Ail specimens may be oxygen-cut or machine-cut. Specimens in the field will be oxygen cut with a coupon-cutting machine. Specimens removed to be sent to a laboratory shall be cut slightly larger to allow for irregularities in the torch drag line. The Company Representative shall carefully mark each specimen as soon as it is removed. Specimens shall be allowed to air cool to ambient temperature before testing. Dunking specimens in water is not permitted. Contractor shall furnish coupon-cutter. DESTRUCTIVE TESTING 6.10.7.1 TENSILE TEST RESULTS In addition to the requirements of API 1104, Paragraph 2.623, if a specimen breaks in the weld or at the junction of the weld and the parent metal, and also fails to develop the minimum specified tensile strength of the parent metal, the welder shall be disqualified. Page 7 6.10.7.2 NICK-BREAK TESTS In addition to the requirements of APi 1104 a welder shall be disqualified if any specimen shows defects exceeding the limitations of API 1104, Paragraph 2.633. 6.10.7.3 ROOT AND FACE BEND TESTS Welds in high test line pipe (API Spec. 5LX) may not bend the full U shape. These shall be considered acceptable if the specimens which crack are broken apart and their exposed surfaces meet the requirements of the nick-break test. Should one of the bend.test specimens fail to meet'these requirements and in the opinion of the Company Representative the lack of penetration Occurring is not representative of the weld, the test specimen may be replaced by an additional specimen adjacent to the one that failed. The welder shall be disqualified if the additional specimen also shows defects exceeding the specified limits. 6.11 ARC BURNS The preferred remedy for an arc burn shall be removal by cutting out a cylindrical portion of the pipe containing the arc burn and replacing it with another cylinder of pipe suitably qualified by inspection or testing. An exception is an arc burn on the cap of a weld which is not serious and may be repaired. On a case by case basis, Company Representative may permit Contractor to repair an arc burn by grinding. Request by Contractor shall be made in advance of any work and the Contractor shall have all necessary equipment on site to perform the repair. The arc burn and associated metallurgical notch if removed by grinding shall not reduce the remaining wall thickness to less than that permitted by the material specification. The ground area shall be smooth with edges blending into the adjacent pipe surface. After visible evidence of the arc burn has been removed by grinding, complete removal of the metallurgical notch can be determined by swabbing the ground area with a 20 percent solution of ammonium persulfate. A blackened spot is evidence of a metallurgical notch and indicates that additional grinding is Page 8 necessary. If after grinding the remaining wall thickness is less than that permitted by the material specification, the portion of pipe containing the arc burn shall be removed as a cylinder. Wall thickness in the ground area shall be verified with a Contractor furnished ultrasonic thickness gage unless other suitable method is approved by Company Representative. All areas exposed to the ammonium persulfate solution shall be thoroughly swabbed with fresh water, rinsed and dried. An arc burn is defined as a discontinuity consisting of any localized remelted metal, heat-affected metal, or change in the surface profile of any part of a weld or base metal resulting from an arc. "Trail" where a perceptible indentation is present from arc impingement shall be considered as an arc burn under these specifications. Arc burns are caused by an energized electrode, by a connection or broken insulation in the welding leads, or by a grounding clamp. Removal or repair of arc burns caused by Contractor shall be at Contractor's expense. 6.12 GROUND CONNECTION AND ELECTRODE HOLDER Ail ground connections shall be securely attached to avoid arc burns on the pipe. Whenever possible, connections shall be placed in the V-groove joint. To further avoid arc burns, electrode holders and electrode leads shall be fully insulated when used for repairing welds on the inside of the pipe. On manifold or pump station construction, the ground connection shall be located as close to the work as practicable to avoid arcing on pump shafts, flange facings and other machined surfaces. Ground connections shall not be made to any pump shaft, motor shaft or coupling nor shall a ground connection be tacked or welded to the work piece being welded. 6.13 LONGITUDINAL WELD SEAM OFFSET Longitudinal seams in adjoining lengths of longitudinally arc-welded pipe shall be located in the top quadrant of the line and within 30 degrees from the top center, unless otherwise required under the bending requirements of this contract specification. Successive joints shall be rotated to right or left to avoid aligning the seams in.adjoining joints. 6.14 TRANSITION JOINTS Prefabricated transition nipples, designed inaccordance with ASME/ANSI B31.4 code, shall be installed at designated locations where the adjoining nominal pipe wall thicknesses 6.15 Page 9 vary more than 3/32-inch. The nipples shall not be less than one-half pipe diameter in length. Tie-in welds should not be made at a transition joint, the addition of a short length of pipe is recommended. Internal tapering may also be accomplished in the field with the use of a mechanical pipe-end-prep machine suited for this purpose. PIPE ENDS 6.15.1 MILL BEVELS Pipe joints will be furnished with ends beveled to 30 degrees plus 5 degrees minus 0 degrees with a root face or land of 1/16-inch plus or minus 1/32-inch. 6.15.2 FIELD BEVELS Pipe ends shall be field beveled by machine tool or machine oxygen cutting to conform to the dimensions shown in the Approved Welding Procedure Specification. Bevels or cuts shall be made in a plane perpendicular to the longitudinal pipe axis. The cost of beveling shall be borne by the Contractor except to eliminate pipe manufacturing defects or other defects not caused by'the Contraetor. Field beveling shall be accomplished by one of the following methods listed below in order of preference. 1. POWERED PORTABLE MECHANICAL PIPE END PREP MACHINE The machine should be accurately positioned and aligned for out-of-roundness of the pipe. A sharp cutting tool is essential and the cut should be chatter,free, non-scalloped and burr-free. 2. STRAP-ON PORTABLE OXYACETYLENE BEVELING MACHINE The band or saddle should be of the proper size and configuration to align the cutting head at desired angle tO pipe allowing no movement other than circumferentially. Torch cut shall produce a high quality smooth surface free of tenacious slag. Torch flame adjustment is critical. A carburizing flame, produced by an excess of acetylene, introduces carbon into the steel which contributes to cracked welds. Carburizing flame cuts shall be rejected. 3. HAND HELD OXYACETYLENE CUTTING TORCH Page 10 In some instances (with Company Representative's prior approval) manual torch cutting may be acceptable provided that the surface finish of the cut is ground by power grinder/sander, or hand filed to the quality of finish and dimensions of a cut made by machine. 6.16 JOINT PREPARATION The area to be cleaned should extend at least one-inch from the end of the bevel on both the inside and outside surfaces. The surfaces to be welded shall be smooth, uniform, free of fins, burrs, laminations, tears, scale, slag, rust or grease and completely dry. Cleaning shall be done with power operated brushes, grinders, sanders or by hand filing. Power brushes shall be of stainless steel and power grinding discs shall not contact the pipe beyond the weld area. 6.17 ~CLEARANCE The working clearance around the pipe for above ground welding should not be less than 16-inches. When the pipe is welded in the trench and especially at tie-ins, the bell-hole shall be sized generously to provide the welder or welders ready access to the joint so that their skill is not hampered. Water shall be pumped out of the bell hole to aid the comfort of the welder and to avoid water splashing onto the weld. 6.18 LINE-UP CLAMPS 6.19 Internal expanding type line-up clamps shall be used wherever practical for pipe sizes 10-3/4-inches O.D. and larger. External clamps may be used for pipe diameters less than 10-3/4-inches O.D. or where the use of an internal line-up clamp is impractical. Internal line-up clamps shall be retained in position, the pipe shall be supported firmly and not moved until 100% of the root bead has been deposited. External line-up clamps shall not be removed until segments of the root bead are deposited uniformly along the circumference of the pipe with a minimum accumulative length of 50% of the circumference. ALIGNMENT - OFFSET Line-up clamps shall be used to fit, align and retain the joint in position during root bead welding. The clamps shall remove out-of-roflndness and provide a uniform joint fit-up Page 11 (high-low) which, for pipe of the same nominal wall thickness, does not exceed 1/16-inch. The root opening shall be as shown in the Qualified Welding Procedure specification to ensure complete root penetration, free of burn-through along the circumference of the join%. Once welding of the root bead is started, hammering on the pipe at that joint is prohibited. Hammer blows to all pipe should be held to a minimum and never used to yield pipe ends to fit. Improper angle of hammer strikes produce stress concentrators (defects) and will be evaluated under the "Material Defects and Damage!' section of this specification. In some cases for pipe of different nominal wall thicknesses where the offset between internal edges of abutting pipe ends exceeds the 3/32-inch maximum permissible offset and there is access to the inside of the pipe for welding, the transition may be made with a tapered weld. The slope of the weld should not be less than 1:4 or more than 1:2 in accordance with ASME/ANSI 31.4. Electrode holders and leads shall be fully insulated when used for welding inside the pipe. The above-noted treatment shall be approved by Company Representative on a case by case basis prior to the start of work. 6.20 PREHEATING Preheating of the pipe and fittings shall be carried out to the satisfaction of the Company Representative. When the term "Preheat" is used in this specification, it is meant to cover both "Preheat Before Welding" and "Concurrent Heat During Welding". Preheating may be accomplished by suitable methods as listed, provided that it is uniform and that the temperature does not fall below the prescribed minimum during the actual welding operation. Preheat does not necessarily mean the addition of heat from external sources. An effective form of preheat is using the residual heat from previous welding passes. When heat from external sources is required the following methods are preferred in this order: 1. PROPANE OR BUTANE HEATING Torch heating with a single burner or ring burners employing "softer" flames such as propane or butane. 2. OXYACETYLENE HEATING Oxyacetylene torches outfitted with "rose-bu~" heating tips utilizing a "neutral" flame~shall be used. A "carburizing" flame, produced by an exce~s of acetylene imparts carbon into the weld and shall not be used. Heating with cutting torch tips is prohibited. 6.21 Page 12 3. RESISTANCE HEATING Finger elements or blankets heated by electrical resistance in nickel chromium wires inside ceramic sleeves and powered by a welding machine. These are made by "Cooperheat". 4. INDUCTION HEATING This method must be approved by the Company before Using. TEMPERATURE CONTROL The temperature shall be carefully controlled by monitoring with pyrometric crayons such as "Tempilstiks" (sulfur and lead-free type), "Tempilabels", direct reading magnetically attached surface thermometers or thermocouple pyrometers. Care shall be taken not to exceed 400"F when methods 1, 2, 3, or 4, previously mentioned, are used. 6.22 CONTROLLED COOLING During extremely cold weather, especially in northern states during the winter, precautions shall be taken to lower the weld cooling rate through the use of insulating covers. Excessive cooling rates during inclement weather will~ significantly impair weld quality and contribute to the-. formation of cracks. 6.23 DISSIMILAR MATERIALS When welding dissimilar materials having different preheating requirements, the material requiring the higher preheat shall govern. 6.24 STRESS RELIEVING Not required. (This is only for wall thicknesses above 1-1/4-inches.) 6.25 AREA TO BE PREHEATED Uniform heat shall cover a band 6-inches wide on each side of the proposed weld. 6.26 CONDITIONS FOR PREHEATING PIPE AND FITTINGS Page 13 Pipe Classification API Std. 5L Grade B ASTM A106 Grade B API Std. 5L X-42, X-46, X-52, X-56 X-60, X~65 Material & Welded Fittings ASTM A105 ASTM A106 Grade B ASTM A234 ,' Minimum I Maximum Wall I Preheat I Preheat Thickness I Temp. I Temp. 0.344 Inches & 250OF Under Over 0.344 [ 250°F Inches WPB(Y42)(Y52) ASTM A694 (F52)(F60) (F65) 0.344 :Inches & Under Over 0.344 Inches 250OF 300OF 400OF 400OF 400OF 400eF JAmbient I Temp. ~ When I Temp. lis below , 40OF ~ When J Temp. lis below ~ 50~F ~ When J Temp. lis below ~ 50OF ~ When I Temp. 'is below , 50OF 6.27 WELDING SAFETY Pipeline construction paralleling high voltage electric transmission lines may produce dangerous electrical capacitative effects. To avoid shock hazards the pipe should be grounded. One method of grounding is to install a 1/2-inch diameter copperweld rod into the ground and connected to the pipe with insulated #8 stranded copper wire with a C-clamp. All grounding methods shall be approved by the Company Representative in advance. 6.28 MINIMUM NUMBER OF WELDERS Contractor shall assign an adequate number of qualified welders to the job to ensure all work is performed in accordance with this specification and good pipeline construction practices. The minimum number of welders that shall work simultaneously on a weld is as follows: Production Welds 4" Thru 8" 10" Thru 18" 20" Thru 28" 30" Thru 36". Root Bead 1 Hot Pass 1 Filler & Cap 1 2 3 4 2 2 2 2 2 2 6.29 Page 14 Tie-In Welds The minimum number of welders for tie-ins from 6-inch thru 36-inch pipe is two. Tie-in welds, once started shall be completed without interruption. MAXIMUM TIME LAPSE BETWEEN BEADS When preheating is required - start the hot pass immediately after completion and cleaning of stringer bead. Always within 3 minutes. The filler beads and cap shall always be completed before the weld area temperature drops below the prescribed minimum or additional preheating shall be required. When preheating is not required - time lapse between root bead and hot pass Shall be 5 minutes maximum. Time lapse between hot pass and first filler bead to completion of the cap may be up to 14 hours maximum, unless otherwise authorized by the Company Representative. 6.30 CLEANING BETWEEN BEADS Ail scale, slag and weld splatter shall be removed from each bead and groove. Cleaning shall be done with power operated rotating grinding discs and wire brushes. Power brushes shall be stainless steel. Grinding shall not contact the pipe beyond the weld area. Metal removed during cleaning shall not so change the geometry of the joint as to adversely affect its strength. Disc grinding shall be used to improve the root bead contour. 6.31 PIPE SUPPORT Ail position welds shall be made over or at the side of the ditch with the pipe resting on skids, earth berms or suitable supports to prevent movement. These supports shall be arranged to prevent toppling resulting from longitudinal pipe expansion and shall be padded to protect the pipe coating from damage. 6.32 ROOT (STRINGER) BEAD WELDING 6.32.1 SHIELDED METAL ARC WELDING (SMAW) The entire root bead shall be deposited with the pipe in-a stationary position during roll or position welding. The movement of pipes during root bead deposition is forbidden. Welders shall commence 6.33 Page 15 welding simultaneously with the work evenly spaced along the pipe circumference. Tack welding is not permitted. The practice of "skating" the electrode with high current to fuse the gap is prohibited. Root pass travel speed on most pipes should be about 15-18 inches per minute. Root beads should have a smooth internal bead about 1/16-inch high and 3/16-inch wide. Two beads shall neither be started nor stopped at the same location. Skimpy beads may be rejected. 6.32.2 GAS METAL ARC WELDING (GMAW) To, preserve weld integrity with this process, the welding arc shall be protected against strong drafts that disperse the shielding gas. Travel speed should be about 15-inches per minute using 0.035 inch wire and 100% carbon dioxide at 35 CFH. Excessive wire "stick-through" or "whiskers" protruding along the interior of the root bead may be cause for weld rejects. The practice of ejectin~ the filler wire through the gap of the joint with the hand qun before the arc is struck may be cause for welder dismissal. HOT PASS (SECOND BEAD) WELDING The root bead joint shall not be subjected to high stresses until the hot pass has been completed. High stresses induced by the cantilever load effect of a pipe joint/double-joint or other lifting operations shall be limited. The root bead shall be cleaned rapidly and thoroughly with power brush and disc grinder. A 5/32-inch thick disc grinder may be used to improve the bead contour. The hot pass shall follow immediately, always within five minutes after completion of the root bead to take advantage of the residual heat. When a delay is encountered between root and hot pass beads, the joint shall be preheated to a minimum of 250°F and a maximum of 400°F before the hot pass is started. 6.34 FILLER BEAD(S) WELDING Ail filler beads shall be made in rapid sequence without allowing the joint to cool. Two beads shall not be started or stopped at the same location. Each bead shall circle the joint before another bead is started. Interpass cleaning shall be with powered stainless steel wire brushes. Any bead deposition faults, such as may be found at starts and stops, shall be removed by grinding. 6.35 FINISH BEAD (COVER PASS OR CAP) WELDING Page 16 The cover pass shall not be started until all of the filler beads are completed. The weld surface shall merge smoothly into the pipe surface with complete fusion. The surface finish of the cover pass shall have closely spaced uniform ripples with a continuous convex cross section. The weld reinforcement shall not be less than 1/32-inch and not more than 1/16-inch above the. pipe surface. The width of the cover pass is determined by the width of the V-groove. The cover pass shall overlap the groove by 1/16-inch on each side. High top buttons shall be ground off to blend with the bead contour. Surface pinholes shall not be spot welded by localized arc impingement. A pinhole may be repaired with a stripper bead at least 2-inches long. The finished bead shall be thoroughly cleaned of slag and weld spatter. 6.36 IDENTIFICATION OF WELDERS 'AND WR?.DING OPERATORS 6.37 The Company Representative will assign an identifying number or letter to each qualified welder and welding operator to mark the section of a weld which he has made. The number or letter and the name of the welder or welding operator will be recorded by the Company Representative. When a welder or welding operator is terminated from the work, his identifying s!anbol shall be voided'and not duplicated. Marking of welds shall be with weather proof crayons. Steel die stamping of the pipe for this purpose is prohibited. WELD QUALITY INSPECTION The quality of welding will be monitored by one or more of the following methods: visual, radiographic or other non-destructive methods, or destructive testing. Other non-destructive methods including magnetic particle and liquid penetrant may be used for maintenance and repair welding. The Company will inspect all welds visually and any or all welds radiographically. 100 percent of fabrication welds and tie-in welds shall be radiographed for the complete weld circumference and up to 100 percent of production welds may be radiographed. The Company shall determine the frequency of radiographic inspection. At intervals, completed welds may be removed from the line for destructive examination. See paragraph "Test Welds". Welds which do not meet the requirements of the method by which they are tested shall be rejected. Radiographic inspection shall produce indications of defects which can be accurately interpreted and evaluated. Welds subjected to non-destructive testing shall be evaluated on the basis Df the following: 6.37.1 Page 17 STANDARDS OF ACCEPTABILITY - NON-DESTRUCTIVE TESTING API 1104 Section 6 shall be used as the standard of acceptable welds with the following additional provisions: Excessive Wire "Stick-Through" with Gas Metal Are Welding Excessive wire "stick-through" or "whiskers" protruding along the interior of the root bead may be cause for a weld rejection and welder dismissal. The codes are silent regarding this., This wire when loosened by scrapers creates havoc with block valves and equipment. It is caused by ejecting the 0.035 inch wire through the joint gap with the hand gun before the arc is struck. The Company Representative'will determine the acceptable extent of "stick-through". Cracks No weld containing cracks either in the weld or in the heat-affected zone of the parent metal, regardless of size or location, shall be acceptable. ~ Undercuttinq Undercut adjacent to the cover bead on the outside of the pipe shall be eliminated by repair. Undercut adjacent to the root bead shall not exceed 2-inches in a continuous weld length of 12-inches or 1/6 the length of the weld, whichever is smaller. When both mechanical and radiographic measurements are available, the mechanical measurements shall govern. 6.38 REPAIR OR REMOVAL OF DEFECTIVE BUTT WELDS Authorization shall be obtained from the Company Representative prior to any work to repair defects beneath the .surface of the cover pass or internal defects along the root bead. 6.38.1 PROCEDURE TO DETERMINE REPAIRS The radiographer shall immediately notify the Company Representative of any welds which have been rejected by radiography. If the weld cannot be repaired, the Page 18 6.38.2 weld shall be removed. If in the opinion of the Company representative the defect can be repaired he shall notify the Contractor who may choose to either cut out such weld or make repairs. If the Contractor chooses to make the repair, the Company Representative shall be notified so he may observe the Contractor and/or radiographer accurately mark the location and limits of the defect on the weld. REPAIR OF DEFECTS BENEATH THE SURFACE OF THE COVER PASS Cracks - No weld containing a crack either in the weld or in the heat-affected zone of the parent metal, regardless of size or location shall be repaired, all such welds shall be cut-out. Defects beneath the surface of the cover pass specifically defined as slag inclusions, porosity or gas pockets may be repaired provided that the following conditions are met: The defects can be removed without grinding completely through the weld. No single area of defect shall exceed 7% of the pipe circumference length. A given single area may consist of one or more defects. Before such repairs are made, such defects shall be entirely removed to clean metal by grinding. All slag and scale shall be removed. Oxyacetylene torch gouging or air carbon arc gouging shall not be used. Before welding, an area 6-inches on each side Of the repair shall be preheated to a minimum of 300°F and a maximum of 400°F and the minimum temperature maintained during repair welding. Temperature shall be monitored with "Tempilstiks" temperature indicating crayons or "Tempilabel" labels or other direct reading temperature indicating method_ approved by the Company Representative. The repair weld shall be made by manual shielded metal-arc electrodes using dry low-hydrogen electrodes AWS E-7018. The minimum length of repair weld shall be 2-inches in length. The starts and stops of welding passes shall not 6.38.3 Page 19 coincide. Ail repairs shall have at least two passes. Each pass shall be ground smooth and the cover pass shall conform to the contour of the original cover pass. Repairs shall be witnessed by the Company Representative. Repairs shall be radiographed and shall comply with the "STANDARDS OF ACCEPTABILITY - NON-DESTRUCTIVE TESTING" of this specification. No further repairs shall be made in these areas. REPAIRS TO INTERNAL DEFECTS ALONG THE ROOT BEAD - BU%~ WELDS Internal repairs shall be limited to pipes 24-inches O.D.'and larger. Internal defects such as burn-through, craters, incomplete fusion or penetration and high-low may be repaired by back-welding with the following requirements or limitations: High-low resulting in incomplete penetration may be repaired by back-welding not to exceed an accumulative length of 25% of the pipe circumference. b. Other internal defects may be repaired by back-welding not to exceed 8-inches in length. Ce For any repair area 4-inches or longer, a new rod shall be used for each bead. Each bead shall begin and end outside the repair area. The cleaning, preheating, welding and inspection methods are the same as outlined under "Repair of Defects Beneath the Surface of the Cover Pass". Electrode holders and cables shall be' the type which are fully insulated too prevent internal arc burns. 6.39 TEST WELDS Company shall reserve the privilege of cutting any weld from the pipeline and then have the weld tested by visual and destructive methods. Destructive testing shall consist of Page 20 sectioning the weld into specimens and testing these as outlined in "Welder Qualification, Destructive Testing" paragraph 6.10.7. If the weld is tested and conforms to all Company requirements, the company will reimburse the Contractor the cost of replacing the weld, except that the Company shall be permitted to cut one (1) test weld made by each welder from the line at no cost to the Company. If the test weld shall fail in any of the standard Company tests, the welder may not be permitted to continue welding on the pipeline. If two or more welders participated in making the weld which failed, the Contractor and Company Representative shall determine which welder or welders were responsible for the defective work. Ail welds which fail shall be replaced at no expense to the Company. Company Representatives shall whenever possible cut test welds from the pipeline in such a manner or at such a time so as to result in a minimum replacement cost. If it is not possible to pull the pipe back into position after a weld has been removed, a nipple with a minimum length of seventy-two (72) inches (unless required otherwise by Company Representative) shall be set in and two (2) welds shall be required to close the line. Company Representative reserves the right to cut any of these replacement welds from the pipe if there is evidence of defective workmanship. A record of results of each weld test shall be made jointly by the Company Representative and the Contractor's Representative. When a weld that has met Company's specification has been cut out, except for the one (1) described weld per welder, the Contractor shall be reimbursed for the weld in accordance with the price quoted in Exhibit "B". The record made jointly by the Company Representative and Contractor shall indicate the location of the weld by stake number, the welder's identification and the results of the test. This record shall be signed by Representative of both the Company and Contractor and must be made on the day the test is performed. No reimbursement will be made for any weld not covered by a Contract Work Order. 6.40 RADIOGRAPHY The Contractor Shall Furnish Radiographic Services Radiography will be used to maintain weld quality control. The frequency of inspection will be specified by the Company. All aspects of the radiographic procedure, exposure geometry, penetrameter selection and placement, radiation protection, and film process shall comply with API Standard 1104. Details ~f Contractor's radiographic procedures shall be presented to Company Representative for approval on Company forms entitled "Radiographic Procedure Specification". Page 21 The Contractor shall demonstrate that his radiographic procedures will produce acceptable results before any production radiography is started. 6.40.1 RADIOGRAPHERS Shall be qualified in accordance with the recommendations of the American Society for Non-Destructive Testing Recommended Practice SNT-TC-IA. Only Level II or Level III shall interpret radiographs. Company shall be furnished copies of technicians certification prior to the start of work, 6.40.2 RADIOGRAPHIC SOURCES X-ray machines or radioisotopes. Internal machines shall be used for pipes 12-inch and larger except at tie-ins and station fabrication. 6.40.3 RADIOGRAPHIC FILM Films of high contrast and relatively fine grain which will produce high resolution shall be used. 6.40.4 PROCESSING DEFECTS Radiographs shall be free from mechanical and processing defects. Any films containing artifacts interfering with the interpretation shall be discarded and the welds shall again be radiographed. 6.40.5 FILM PROCESSING Radiographs shall be processed to allow storage of film without discoloration for at least 3 years. 6.40.6 FILM IDENTIFICATION Production radiography shall not start until the Company Representative has specified the identification procedure. The markers shall be placed on the pipe on the downstream side of the weld so that the numbers will be read clockwise when viewed from the upstream side. Whenever more than one film is used to inspect a weld, the markers shall appear on each film and adjacent films shall overlap. 6.40.7 6.40.8 6.40.9 6.40.10 Page 22 RADIATION PROTECTION The radiographer shall be held responsible for the safety of all people and domesticated animals in the vicinity. Each radiation area shall be clearly delineated and shall be conspicuously posted with signs bearing the radiation symbol. REJECTED WELDS The radiographer shall immediately notify the Company Representative of any welds which have been rejected by radiography. REPAIRED WELDS Welds which have.been rejected by radiographic inspection for defects other than cracks and subsequently repaired, shall be re-radiographed. In order to verify repair was made to the defect area, the repair radiograph(s) shall be of sufficient length to provide correlation to the original radiograph for that weld. No further repairs shall be allowed in these areas. RECORDS The radiographer shall maintain daily records to show for each weld radiographed, the x-ray number and location of the weld, the size and type of pipe or fitting, the material specification, the wall thickness, the location and type of any defect and whether the weld is accepted or rejected. The Company will keep a record of qualified radiographers. A copy of the daily records and film of accepted welds shall be handed to the Company Representative each working day. Films shall remain the property of the Company.