Welding of Pipelines and Related Facilities PDF

WELDING OF PIPELINES AND RELATED FACILITIES 3 3.1.2 back weld repair Repair weld made at the back side of a groove weld. 3.1.3 branch weld Completed groove and/or fillet weld joining a set-on or set-in branch pipe or a set-on or set-in branch fitting to a run pipe. 3.1.4 company Owner company or t...

WELDING OF PIPELINES AND RELATED FACILITIES 3 3.1.2 back weld repair Repair weld made at the back side of a groove weld. 3.1.3 branch weld Completed groove and/or fillet weld joining a set-on or set-in branch pipe or a set-on or set-in branch fitting to a run pipe. 3.1.4 company Owner company or the engineering agency in charge of construction. NOTE A company may act through an inspector or another authorized representative. 3.1.5 contractor That which includes the primary contractor and any subcontractors engaged in work covered by this standard. 3.1.6 cover pass repair Repair to the weld face located and contained within the external reinforcement, including external undercut. 3.1.7 defect Imperfection of sufficient magnitude to warrant rejection based on the acceptance criteria in this standard. 3.1.8 double repair Second repair in a previously repaired area of a completed weld; typically referred to as a “repair of a repair” or a “rerepair.” 3.1.9 full thickness repair Repair weld originating from the weld face that penetrates completely through the weld thickness. 3.1.10 grinding Mechanical means to remove weld metal using abrasive methods. 3.1.11 imperfection Discontinuity or irregularity that is detectable by methods outlined in this standard. 3.1.12 indication Evidence obtained by nondestructive testing. 3.1.13 internal concavity IC Bead that is properly fused to and completely penetrates the pipe wall thickness along both sides of the bevel but whose center is somewhat below the inside surface of the pipe wall. NOTE The magnitude of concavity is the perpendicular distance between an axial extension of the pipe wall surface and the lowest point on the weld bead surface. 4 API STANDARD 1104 3.1.14 mechanized welding Process where parameters and torch guidance are controlled mechanically or electronically but may be manually varied during welding to maintain the specified welding conditions. 3.1.15 multiple repairs More than one individual repair area location in a completed weld. 3.1.16 partial thickness repair Repair weld originating from the weld face or root bead surface extending into the weld but does not completely penetrate through the weld thickness. 3.1.17 position welding Welding in which the pipe or assembly is not rotating while the weld is being deposited. 3.1.18 qualified welder Welder who has demonstrated the ability to produce welds that meet the requirements of Section 5, Section 6, or Section 10 of this standard. 3.1.19 qualified welding procedure specification Tested and proven detailed method by which sound welds with suitable mechanical properties can be produced. 3.1.20 radiographer Person who performs radiographic operations. 3.1.21 repair Any grinding or welding on a completed weld to correct an individual defect or accumulation of defects in the weld that has been rejected by visual or nondestructive testing in accordance with acceptance criteria in this standard. 3.1.22 repair area One individual repair location in a completed weld that may include a single defect or accumulation of defects. 3.1.23 repair procedure Tested and proven detailed method by which sound repairs with suitable mechanical properties can be produced. 3.1.24 repair weld Weld made to repair a defect (or defects) found in a completed weld. 3.1.25 rework During the welding or after the weld has been completed, the removal of an imperfection that requires grinding and/or welding that is performed prior to visual or nondestructive testing of a completed weld. NOTE Rework is not a repair. WELDING OF PIPELINES AND RELATED FACILITIES 5 3.1.26 roll welding Welding in which the pipe or assembly is rotated while the weld metal is being deposited at or near the top center. 3.1.27 root bead First or stringer bead that initially joins two sections of pipe, a section of pipe to a fitting, or two fittings. 3.1.28 semiautomatic welding Arc welding with equipment that controls only the filler metal feed. The advance of the welding is manually controlled. 3.1.29 stacked defects Individual imperfections aligned in the radial (through thickness) direction, at the same circumferential location, and exceed the acceptance standards. 3.1.30 weld Completed weld joining two sections of pipe, a section of pipe to a fitting, or two fittings. 3.1.31 welder Person who makes a weld. 3.2 Acronyms and Abbreviations For the purposes of this standard, the following acronyms and abbreviations apply. A welding current (amp) a imperfection height (in. or mm) AC alternating current AI accumulation of imperfections BT burn-through C carbon c imperfection half length (in. or mm) CE carbon equivalent CO2 carbon dioxide CP cluster porosity Cr chromium CTOD crack tip opening displacement Cu copper CVN Charpy V-Notch D pipe outer diameter (in. or mm) DAC distance amplitude correction DC direct current dn J integral to CTOD conversion factor (unitless) DWE double-wall exposure 6 API STANDARD 1104 DWV double-wall viewing D/t pipe diameter-to-wall thickness ratio E Young’s modulous (ksi or MPa) ECA engineering critical assessment ESI elongated slag inclusion EU undercutting adjacent to the cover pass EW electric resistance or electric induction weld FAC failure assessment curve FAD failure assessment diagram HAZ heat-affected zone HB hollow bead porosity H2S hydrogen sulfide i number ith cyclic stress, from 1 to k IC internal concavity ICP inadequate cross penetration ID inside diameter IF incomplete fusion IFD incomplete fusion due to cold lap IP inadequate penetration without high-low IPD inadequate penetration due to high-low IQI image quality indicator ISI isolated slag inclusion IU undercutting adjacent to root pass J heat input (joules per in.) Je elastic part of J integral (ksi in. or MPa mm) k total number of cyclic stress levels KI stress intensity factor [ksi (in.)1/2 or MPa (mm)1/2] Kr toughness ratio in FAD format (unitless) LB linear buried Lr stress ratio in FAD format (unitless) L cutoff r cutoff stress ratio in FAD format (unitless). LS linear surface Kr toughness ratio Mn manganese Mo molybdenum MPS manufacturing procedure specification NDT nondestructive testing n strain hardening exponent (unitless) Ni nickel Ni number of cycles at the ith cyclic stress level WELDING OF PIPELINES AND RELATED FACILITIES OD outside diameter Pr normalized applied stress or load level, Pr = σa/σ f (unitless) PWHT postweld heat treatment S welding arc speed (in. per minute) S* is the spectrum severity SAWH submerged-arc helical weld SAWL submerged-arc longitudinal weld SCC stress corrosion cracking SMTS specified minimum tensile strength SMYS specified minimum yield strength Sr stress ratio SWE single-wall exposure SWV single-wall viewing t specified pipe wall thickness (in. or mm) T transverse TCG time-corrected gain V vanadium V welding arc voltage (volt) VC volumetric cluster VI volumetric individual VR volumetric root WT wall thickness Y/T yield-to-tensile ratio α ratio of pipe diameter to wall thickness, α = D/t (unitless) β ration of imperfection length to pipe circumference, β = 2c/πD, (unitless) ∆σ i ith cyclic stress range, in kips per in.2 (ksi) δe elastic part of CTOD (in. or mm) δmat CTOD toughness (in. or mm) εt uniform strain (unitless) η ν ratio of imperfection height to pipe wall thickness, η = a /t, (unitless) Poisson’s ratio (unitless) π pi σa σc σf σ t, T σ y, Y maximum axial design stress (ksi or MPa) plastic collapse stress (ksi or MPa) flow stress of the pipe material (ksi or MPa) ultimate tensile strength of the pipe material (ksi or MPa) specified minimum yield strength of the pipe material, or SMYS, (ksi or MPa) 7 8 API STANDARD 1104 4 Specifications 4.1 Equipment Welding equipment, both gas and arc, shall be of a size and type suitable for the work and shall be maintained in a condition that ensures acceptable welds, continuity of operation, and safety of personnel. Arc welding equipment shall be operated within the amperage and voltage ranges given in the qualified welding procedure specification. Gas welding equipment shall be operated with the flame characteristics and tip sizes given in the qualified welding procedure specification. Equipment that does not meet these requirements shall be repaired or replaced. 4.2 Materials 4.2.1 Pipe and Piping Components This standard applies to the welding of pipe and piping components that conform to material and product specifications including, but not limited to: a) API specifications, b) ASME International specifications, c) ASTM International specifications, d) Manufacturers Standardization Society (MSS) specifications, e) American National Standards Institute (ANSI) specifications. This standard also applies to materials with chemical and mechanical properties that comply with one of the specifications listed in Items a) through e) above, even though the material is not manufactured in accordance with the specification. 4.2.2 Filler Metals and Fluxes 4.2.2.1 Types All filler metals and fluxes shall conform to one of the following, except as provided below: a) AWS A5.1, b) AWS A5.2, c) AWS A5.5, d) AWS A5.17, e) AWS A5.18, f) AWS A5.20, g) AWS A5.23, h) AWS A5.28, i) AWS A5.29. Filler metals and fluxes that do not conform to the specifications above may be used provided the welding procedure specifications involving their use are qualified. WELDING OF PIPELINES AND RELATED FACILITIES 9 4.2.2.2 Storage and Handling Filler metals and fluxes shall be stored and handled to avoid damage to them and to the containers in which they are shipped. Filler metals and fluxes in opened containers shall be protected from deterioration, and filler metals that are coated shall be protected from excessive changes in moisture. Filler metals and fluxes that show signs of damage or deterioration shall not be used. 4.2.3 Shielding Gases 4.2.3.1 Types Atmospheres for shielding an arc are of several types and may consist of inert gases, active gases, or mixtures of inert and active gases. The purity and dryness of these atmospheres have great influence on welding and should be of values suitable for the process and the materials to be welded. The shielding atmosphere to be used shall be qualified for the material and the welding process. 4.2.3.2 Storage and Handling Shielding gases shall be kept in the containers in which they are supplied, and the containers shall be stored away from extremes of temperature. Gases shall not be field intermixed in their containers. Gases of questionable purity and those in containers that show signs of damage shall not be used. 5 Qualification of Welding Procedures with Filler Metal Additions 5.1 Procedure Qualification This section applies to the qualification of welding procedures using manual welding and semiautomatic welding using filler metal additions. Section 12 applies to the qualification of welding procedures using mechanized welding with filler metal additions. Section 13 applies to the qualification of welding procedures for automatic welding without filler metal additions. When a welding procedure specification uses a combination of manual/semiautomatic and mechanized welding, the requirements of Section 5 and Section 12 apply to their portions of the welding procedure specification. Before production welding is started, a detailed welding procedure specification shall be established and qualified to demonstrate that welds with suitable mechanical properties (such as strength, ductility, and hardness) and soundness can be made by the procedure. The quality of the welds shall be determined by destructive testing. These procedures shall be adhered to except where a change is specifically authorized by the company, as provided for in 5.4. 5.2 Record The details of each qualified procedure shall be recorded. The record shall show complete results of the procedure qualification test. Forms similar to those shown in Figure 1 and Figure 2 should be used. The record shall be maintained as long as the procedure is in use. 5.3 Welding Procedure Specification 5.3.1 General The welding procedure specification shall include the information specified in 5.3.2 where applicable. 5.3.2 Specification Information 5.3.2.1 Process The specific process, method of application, or combination thereof shall be identified. 10 API STANDARD 1104 Reference: API 1104, 5.2 (The “sample form” usage does not exclude adding other details.) WELDING PROCEDURE SPECIFICATION NUMBER _______________ For ________________________________________ Welding of _________________________________________________ Pipe and fittings Process ____________________________________________________________________________________________________________ Material ____________________________________________________________________________________________________________ Pipe outside diameter and wall thickness __________________________________________________________________________________ Joint design ________________________________________________________________________________________________________ Filler metal and number of beads ________________________________________________________________________________________ Electrical or flame characteristics ________________________________________________________________________________________ Position ____________________________________________________________________________________________________________ Direction of welding __________________________________________________________________________________________________ Number of welders ___________________________________________________________________________________________________ Time lapse between passes ____________________________________________________________________________________________ Type and removal of lineup clamp _______________________________________________________________________________________ Cleaning and/or grinding ______________________________________________________________________________________________ Preheat/postweld heat treatment ________________________________________________________________________________________ Shielding gas and flow rate _____________________________________________________________________________________________ Shielding flux _______________________________________________________________________________________________________ Speed of travel _________________________________ Plasma gas flow rate ____________________________________________________ Plasma gas composition _______________________________________________________________________________________________ Plasma gas orifice size ________________________________________________________________________________________________ Sketches and tabulations attached _______________________________________________________________________________________ Tested ______________________________________________ Welder _____________________________________________ Approved ___________________________________________ Welding supervisor ____________________________________ Adopted ____________________________________________ Chief engineer _______________________________________ 1/16 in. (1.6 mm) 1/32 in. to 1/16 in. (0.8 mm to 1.6 mm) T Approximately 1/16 in. (1.6 mm) 1/16 in. ± 1/32 in. (1.6 mm ± 0.8 mm) Standard V-bevel Butt Joint Approximately 1/8 in. (3 mm) 5 4 3 2 T 1 Sequence of Beads NOTE Dimensions are for example only. ELECTRODE SIZE AND NUMBER OF BEADS Bead Number Electrode Size and Type Voltage Amperage and Polarity Figure 1—Sample Welding Procedure Specification Form Speed WELDING OF PIPELINES AND RELATED FACILITIES 11 COUPON TEST REPORT Date __________________________________________________ Test No. __________________________________________ Location _____________________________________________________________________________________________________ State__________________________________________________ Weld Position: Roll Ƒ Fixed Ƒ Welder ________________________________________________ Mark ____________________________________________ Welding time____________________________________________ Time of day _______________________________________ Mean temperature _______________________________________ Wind break used ___________________________________ Weather conditions _____________________________________________________________________________________________ Voltage ________________________________________________ Amperage ________________________________________ Welding machine type_____________________________________ Welding machine size _______________________________ Filler metal ___________________________________________________________________________________________________ Reinforcement size _____________________________________________________________________________________________ Pipe type and grade ____________________________________________________________________________________________ Wall thickness __________________________________________ Outside diameter___________________________________ 1 2 3 4 5 6 7 Coupon stenciled Original specimen dimensions Original specimen area Maximum load Tensile strength Fracture location Ƒ Procedure Ƒ Welder Ƒ Qualifying test Ƒ Line test Ƒ 4XDOL¿HG Ƒ 'LVTXDOL¿HG Maximum tensile ______________ Minimum tensile ______________ Average tensile ______________ Remarks on tensile strength tests ________________________________________________________________________________ 1. __________________________________________________________________________________________________________ 2. __________________________________________________________________________________________________________ 3. __________________________________________________________________________________________________________ 4. __________________________________________________________________________________________________________ Remarks on bend tests _________________________________________________________________________________________ 1. __________________________________________________________________________________________________________ 2. __________________________________________________________________________________________________________ 3. __________________________________________________________________________________________________________ 4. __________________________________________________________________________________________________________ Remarks on nick break tests _____________________________________________________________________________________ 1. __________________________________________________________________________________________________________ 2. __________________________________________________________________________________________________________ 3. __________________________________________________________________________________________________________ 4. __________________________________________________________________________________________________________ Test made at ___________________________________ Tested by ______________________________________ NOTE Date _________________________________________________ Supervised by __________________________________________ Use back for additional remarks. This form can be used to reporWHLWKHUDSURFHGXUHTXDOL¿FDWLRQWHVWRUDZHOGHUTXDOL¿Fation test. Figure 2—Sample Coupon Test Report 12 API STANDARD 1104 5.3.2.2 Materials The materials to which the procedure applies shall be identified. API 5L pipe, as well as materials that conform to other product specifications, may be grouped (see 5.4.2.2), provided that the qualification test is made on the material with the highest specified minimum yield strength (SMYS) in the group. 5.3.2.3 Diameters and Wall Thicknesses The ranges of specified outside diameters (ODs) and specified wall thicknesses over which the procedure is applicable shall be identified. Examples of suggested groupings are shown in 6.2.2 d) and 6.2.2 e). 5.3.2.4 Joint Design The specification shall include a sketch or sketches of the joint that show the angle of bevel, the size of the root face, and the root opening or the space between abutting members. The shape and size of fillet welds shall be shown. If a backing is used, the type shall be designated. 5.3.2.5 Filler Metal, Flux, and Number of Beads The sizes and classification number of the filler metal and flux and the minimum number and sequence of beads shall be designated. For any filler metals with a G suffix designator only, the manufacturer and trade name shall also be designated. 5.3.2.6 Electrical Characteristics The current and polarity shall be designated, and the range of voltage and amperage for each type and size of electrode, rod, or wire shall be shown. 5.3.2.7 Flame Characteristics The specification shall designate whether the flame is neutral, carburizing, or oxidizing. The size of the orifice in the torch tip for each size of rod or wire shall be specified. 5.3.2.8 Position The specification shall designate roll or position welding. 5.3.2.9 Direction of Welding The specification shall designate whether the welding is to be performed in an uphill or downhill direction. 5.3.2.10 Time Between Passes The maximum time between the completion of the root bead and the start of the second bead, as well as the maximum time between the completion of the second bead and the start of other beads, shall be designated. 5.3.2.11 Type and Removal of Lineup Clamp The specification shall designate whether the lineup clamp is to be internal or external or if no clamp is required. If a clamp is used, the minimum percentage of root bead welding that shall be completed before the clamp is released shall be specified.