Double-weld exposure for single welded to be visible on the radiograph of a pipe viewing weld whose weld thickness is 0. Be demonstrated by the contractor to prove the application of the procedure and system B. Be proven on welds containing defects and acceptable imperfections produced by approved welding procedures on actual production pipe material C. Be proven to be as accurate as radiographs made of the demonstration welds D. Be documented by detailing the di ferences between the radiographic and ultrasonic examination of the demonstration welds E.
Section 1 2. The quality of test welds shall be determined by both destructive testing and nondestructive testing and shall meet the requirements of subsection 5. The use of nondestructive testing is in addition to the destructive tests required in Section 5. The list is the same as that in subsection 5.
Subsection 1 2. Section 1 2 b Paragraph 1 2. Paragraph 1 2. Similar to Section 6, welding operators shall be qualifed by welding a test coupon which shall be tested either by d estru cti ve m eth od s or n on d estru cti ve m eth od s, or both , an d sh al l m eet th e req u i rem en ts of su bsecti on.
In addition, welding operators shall be qualifed on the type of equipment to be used in prod u cti on wel d i n g. They are: a A ch an g e from on e wel d i n g process, m od e of tran sfer, pol ari ty, or m eth od of appl i cati on to. A welding operator who qualifes in the fxed position shall also be qualifed to perform welds i n th e rol l ed posi ti on. A record shall be made of the tests and results required by subsection 1 2.
A form similar to that shown in Figure 2 on page 1 1 should be used, but any form is suitable as long as it records all of the required in formation. A list o f qualifed operators and the procedures for which they are qualifed shall be maintained. An operator may be required to requalify if a question arises about his competence.
Production welds shall be inspected and tested in accordance with Section 8. Section 12 CWI Seminar. Is required B. Must be of the internal type A. A change from V groove to U groove C. Must be of the external type B. An increase in the time between the end. Section 1 2 E. Must be specifed in the procedure of the fll passes and the start of the cap pass D.
An increase in the range o f gas f ow 1 2. A change in the plasma gas orifce specifcation for mechanized welding diameter processes? Pipe wall thickness B. Direction of welding C. Postweld cleaning D. Welding process E. Pipe diameter. Subsection 6. Subsection 1 1. Subsection 1 3. Does not need to be recorded B. Need not be addressed if current and voltage are recorded C.
May be changed at the discretion of the welding operator D. Must be recorded for each pass E. If the required tests are acceptable, the welding variables at which these two test welds are made will establish the maximum and minimum values permitted for welding voltage, welding current, axial speed, time intervals in the weld cycle, and upset stroke on the resulting welding procedure.
The number of specimens depends on the outside diameter of the pipe, with larger diameter pipe Section 1 3. In order to locate the notch on the bond line, however, the edges of the nick break specimen must be polished and macroetched to reveal the bond line. Other than that, the preparation and testing for nick break tests are the same as previously described in S ec ti o n 5.
The preparation, testing, and acceptance criteria are the same as previously described for side bend tests in Section 5. Th e reco rd. Th ey. Section 13 CWI Seminar. Section 1 3 This paragraph lists the essential variables for the qualifcation of welding procedure specifcations. Th ey are:. A list o f qualifed operators and the procedures for which they are qualifed shall be m ai n tai n ed.
Rejected welds must be removed from the line. Paragraph 1 3. Section 1 3. This is the temperature above which the ferrite-to-austenite transformation is complete. This heat treatment must be followed by controlled cooling or still-air cooling.
Other defects may be removed by grinding, chipping, or gouging or a combinatoin of these , followed by a repair weld in accordance with Section 1 0. All repair welds must be approved by the company. Section 1 3 E. Al l of th e above are correct 1 3. After f ash removal and postweld heat treatm en t.
Before fnal heat treatment B. Axi al speed tol eran ces D. After m ech an i cal testi n g. Pi pe m ateri al E. Not less than 24 hours after the weld D. Fi l l er m etal h as cool ed to room tem peratu re. This heat from a f ash butt qualifcation weld, the treatment must meet which of the maximum size slag inclusion allowed is: ollowing requirements?
H ow many and what type of test specimens are A. ISIs are not allowed tests B. Unlimited tests and 4 side bend tests C. It must be determined by testing 1 3. A change in welding position B. A change in welding current tolerance C. A change in pipe material D.
Annex A ofers an alternative way to determine acceptance criteria by means of fracture mechanics analysis and ftness for purpose considerations alternatively called engineering critical assessment for ECA. These alternative acceptance criteria permit larger imperfections, but require additional testing.
These alternative criteria apply only under the following conditions: a Circum ferential girth welds between pipes of equal specifed wall thickness. In order to use Annex A, a stress analysis must be performed to determine the maximum axial design stress anticipated during construction, installation, and operation. This analysis must include consideration of potential dynamic loads on girth welds, such as loads from closure of check valves. Paragraph A2.
The essential variables for welding procedures to be used with this annex, however, are very di ferent and have more restricted. They are listed below: a A change in the welding process, mode of arc transfer, or method of application. Paragraph A. The tension test specimen geometry shown in Figure A. Charpy V-notch impact testing of both the weld metal and the heat-afected zone is also required. For each location in the weldment, three specimens shall have the notch located in the.
Annex A coarse-grained heat-afected zone and three shall have the notch located on the weld centerline. All specimens shall be tested at the lowest design temperature. The average absorbed energy for each set of three specimens shall be no less than 30 ft-lbs and the minimum absorbed energy for each set o f three specimens shall be no less than 22 ft-lbs.
These criteria apply to both full-sized and subsized specimens. The location and orientation of the crack-tip opening displacement CTOD specimens required for this test are shown in Figures A. Both the weld and the heat-afected zone must be tested. For each location in the weldment, fatigue precracks shall be located in the center of the weld and in the coarse-grained heat afected zone. The qualifcation criteria in paragraph 1 2.
The minimum CTOD value of all six specimens must be greater than 0. Welders must be qualifed in accordance with Section 6. For mechanized welding, the welding operators must be qualifed in accordance with subsection 1 2. This will typically require the use of ultrasonic testing. Regardless of the NDT method employed, its accuracy must frst be established see paragraph 1 1.
Option 1 is described in paragarph A. Planar imperfections have sharp ends that can easily propagate to failure in the presence of a transverse tensile stress, particularly i f the stress is cyclic in nature. These f aws are the most critical type in any pressurized pipe. Volumetric imperfections, addressed in paragraph A. Buried volumetric imperfections, such as slag or porosity, contained in high-toughness material are less likely to cause a catastrophic failure than are planar imperfections.
These buried volumetric imperfections can be treated conservatively like they are planar and more dangerous or by the simplifed method o f Table A.
In this table, limits are given for the height or width and length, for both porosity and slag, for pipe of a given wall thickness, t. The acceptance criteria for unrepaired arc burns are given in Table A. Arc burns that contain cracks visible to the eye or on conventional radiographs are not covered by this annex and shall be repaired or removed.
When multiple imperfections exist in close proximity, they may behave as one. Figure A. If a repair is indicated, any interacting imperfections shall be repaired in accordance with A.
Annex A. The type, location, and dimensions of all accepted imperfections must be recorded. This information must be stored with radiographs or other pipeline inspection records. Imperfections that violate the rules of this annex shall be repaired or removed according to Sections 9 and 1 0.
Subsection A. External exposure of buried pipe to A5. Which of the following mechanical carbonates and nitrates in the soil has tests is required for the qualifcation o f been shown to produce: welding procedures when the use of the alternative girth weld acceptance criteria A.
A few cases of axi al cracki n g in Annex A is authorized by the company? M an y cases of ci rcu m feren ti al cracki n g. Th e CTOD fractu re tou g h n ess test. Th e CVN tou g h n ess test. Axi al cracki n g d u e to axi al stress C. Annex A E. Th e ten si on test.
Using the simplifed method o f Table A. How many options are available in Annex girth weld is: A for the determination of acceptance limits for planar imperfections? What is the primary purpose of Annex A? Ch arpy V N otch i m pact testi n g. The maximum depth permitted for an B. To d el i n eate between ci rcu m feren ti al an d. Which of the following is used to sp eci f cat i o n s fo r u se i n servi ce. A vi su al wel d i n specti on. Each month B.
By radiographic testing C. By Charpy V-Notch impact testing E. In the presence of state regulators. Typically, validated ftness- for-purpose criteria provide for:. Higher tensile and yield strength values B. More generous acceptance criteria for imperfections Annex A.
CVN acceptance criteria D. Qualifcation o f welding procedures to be used with Annex A shall be in accordance with:. Annex B: In-service Welding B. This annex provides welding practices for making repairs to and installing appurtenances on piping systems that are in service.
Of particular importance are the welds that melt into the carrier pipe since they cool at an accelerated rate due to the quenching efect of the f uid f owing through the carrier pipe.
The welds that melt into the carrier pipe are either fllet welds or branch connection welds. Fillet welds are used to join the ends o f encirclement sleeves to the carrier pipe. Welding attachments onto in-service pipelines poses two major risks: 1 burning through the pipe wall and 2 hydrogen cracking. Burning through the pipe wall is unlikely when the wall thickness is 0.
Although Annex B explains how to prevent both of these problems, the major focus of Annex B is on the prevention of hydrogen cracking. Annex B. For hydrogen cracking to occur, three conditions must be satisfed simultaneously: 1 hydrogen in the weld, 2 a crack susceptible microstructure and 3 a tensile stress acting on the weld. Conversely, to prevent hydrogen cracking, one of these must be reduced or eliminated.
Since these welds are made on pipelines that have been in service, hydrogen is always present and cannot be reduced to su f cient levels. In addition, residual tensile stresses are present in every weld due to the inherent shrinkage resulting from solidifcation and subsequent cooling from high temperatures. As a result, the primary technique used to prevent hydrogen cracking in in-service welds is the prevention of a crack-sensitive microstructure.
To make matters worse, in-service welds are made onto pipe carrying f owing f uids which accelerate the cooling rate and, therefore, promote the formation of crack-sensitive phases in steels, particularly martensite. Because of this combination of factors, the most efective approach for preventing hydrogen cracking in in-service welds is the use of a welding procedure that has a high enough heat input to overcome the quenching efects of the f uid f owing through the carrier pipe.
As an alternative, temper bead welding sequences are also efective at producing multi-pass welds in which the heat-afected zone in the carrier pipe has a tempered microstructure, known to be more resistant to hydrogen cracking. This subsection lists the essential variables and tests required to qualify in-service welding procedures. Paragraph B. One o f these variables is the carbon equivalent of the carrier pipe to be welded.
The pipeline operating conditions must also be addressed on the procedure specifcation. This can be addressed by speci fying the f uid type and its f ow rate. Again, conditions may be grouped.
For procedures designed to overcome the quenching efect of the f owing contents by using a su f ciently high heat input, the heat input range should be specifed. The minimum value o f this range should be that used to weld the procedure qualifcation coupon.
For procedures designed to overcome the quenching efect of the f owing contents by using a temper bead sequence, the weld deposition sequence, including bead size and overlap, should be specifed. The required heat input range for each temper bead layer should also be specifed on a temper bead procedure specifcation.
For in-service welds, specifed minimum yield strength is no longer an essential variable, meaning that in- service welding procedures are valid for all pipe grades. However, since hydrogen cracking is more likely. Annex B on pipe materials having greater hardenability as measured by the carbon equivalent , an increase in the carbon equivalent over that used to qualify the procedure is now an essential variable. So, for in-service welds, the MTR of the carrier pipe to be welded should be available so that the carbon equivalent can be calculated from the listed composition.
When the in-service welding procedure is qualifed, the carrier pipe used in the test coupon should have a carbon equivalent no less than that of the production carrier pipe. Ideally, the carrier pipe used for the qualifcation test should have a very high carbon equivalent. In that case, the in-service welding procedure would be qualifed for a large range of carbon equivalents, up to and including that used in the qualifcation test weld.
For in-service fllet and branch welds, pipe wall thickness is no longer an essential variable, so these procedures are qualifed for all wall thicknesses; however, the note in paragraph B. Finally, for in-service welds, pipeline operating conditions are an important essential variable, with an increase in the severity of the conditions being cause for requalifcation.
So, the procedure should be qualifed under the most severe quenching conditions. By the same logic, paragraph B. This condition has been shown to produce thermal conditions more severe than typical in-service welding applications. Therefore, a procedure qualifed under this condition qualifes for all in-service conditions.
In general, in-service welds that melt into the carrier pipe, including repairs to weld depositions, will be tested using the nick break tests described in subsection 5. The additional tests required in this table are macrosection tests, detailed in paragraph B. Longitudinal seam welds of full-encirclement sleeves should be tested with the tension tests, bend tests and nick break specimens required in subsection 5.
Branch and sleeve welds should be tested with the nick break tests in Section 5. These are shown schematically in Figure B. They may be machine cut or oxygen cut oversized. These weld cross sections shall then be ground, polished, etched with a suitable etchant and examined visually without dye penetrants and with little or no magnifcation typically at 1 0X or less.
Two of the four macroetch specimens for branch and sleeve welds and both of the specimens for weld deposition repair shall be examined by hardness testing in accordance with ASTM E At least fve indentations shall be made in the coarse-grained HAZ at the toe of each weld cross section using a Vickers indenter and a 1 0 kg load to determine the maximum hardness.
Specifc specimens may be cut for these tests or the remaining portion of the nick break specimens can be used. Both options are shown in Figure B. When remnants of the sleeve or branch welds are used, the sleeve and branch welds must be removed to, but not below, the surface of the sleeve.
Undercut should not be removed. This is identical to the requirements in paragraph 5. The acceptance criteria for these bend specimens is exactly the same as that found in paragraph 5.
A welder with only that qualifcation is qualifed for in-service welding in accordance with the essential variable limits of subsection 6.
However, this annex modifes those qualifcation ranges as explained in the next few paragraphs. I f that qualifcation test is welded on pipe less than 1 2. I f that qualifcation test is welded on pipe 1 2. A welder who meets both the multiple qualifcation requirements of subsection 6. Welders who perform weld deposition repairs are limited based on the positions in which they perform the test welds.
Similar to the weld coupon required for the procedure qualifcation test, flling the carrier pipe with f owing water during welding should produce conditions equal to or more severe than typical in-service conditions.
Welders qualifed on such a coupon are therefore qualifed for all typical in-service applications. The coupon should also be welded following either the heat input, temper bead, or weld deposition repair welding procedure, as applicable. Annex B Paragraph B. For longitudinal seam welds in full encirclement sleeves, the type and number of test specimens required for welder qualifcation are listed in Table B. Factors such as operating pressure, f ow conditions, and minimum wall thickness in the area to be welded should be considered.
For saddle and sleeve welds, the gap between the sleeve and the carrier pipe should be minimized to permit easy fusion of the carrier pipe. Weld metal build-up on the carrier pipe is one way to minimize any gap that might be present.
Clamping devices are recommended. For longitudinal butt welds of full encirclement sleeves, the root opening should be su f cient to permit full penetration. Use o f a mild steel back-up strip or suitable tape may be necessary to prevent penetration into the carrier pipe.
Recommended welding sequences, sleeve designs and geometries are provided in paragraph B. For full encirclement sleeves requiring circum ferential fllet welds, the longitudinal seams should be completed before beginning the sleeve welds to minimize the residual stresses on the sleeve welds.
When making the circum ferential fllet welds, one sleeve weld should be completely welded before beginning the other. Regardless of the type of ftting used, the welding sequence should always be chosen to minimize residual stresses. In-service welds must meet the acceptance criteria of Section 8 except for the additional or alternative requirements in subsection B. Since hydrogen cracking is the primary weld quality concern and most hydrogen cracks are located under the weld bead and do not break the surface, the inspection method must be able to detect underbead and toe cracks.
A combination of magnetic particle and ultrasonic testing is recommended for inspecting sleeve-to-saddle and branch-to-carrier pipe welds. Radiographic testing is not a good candidate for detecting these types of cracks. Since it takes time for hydrogen trapped in the weld to di fuse to the coarse-grained region of the HAZ to cause the cracking, it is important to establish a suitable delay time after welding prior to inspection to ensure that inspection is conducted after the cracking has had adequate time to develop.
For weld deposition repair, the weld length is defned as the maximum weld length in the direction in which the f aw is oriented. The requirements in Section 1 0 apply to the repair and removal of defects found in in-service welds. The two main concerns with welding on B4. For the qualifcation testing o f in-service in-service pipelines are: branch and sleeve weld procedures, each macrosection test specimen: A. Burn-through and hydrogen cracking B.
Weld cooling rates and the weld A. Should be ground on both sides to at sequence least a grit fnish and etched C. Yield strength o f the pipe and fttings B. Should be ground on both sides to at D. Tensile strength of the pipe and the weld least a grit fnish and etched sequence C. Should be ground on at least one face to.
Annex B E. Joint ft-up and the weld sequence at least a grit fnish and etched D. Should be ground on at least one face to at least a grit fnish and etched B2. For in-service welds on a full- E. Shall be machine cut encirclement ftting:. The circumferential welds should B5. For in-service welder qualifcation for be completed before beginning the longitudinal seam welds on pipe with a longitudinal seams 0.
The circumferential welds need not be number o f test specimens required are: made C. The longitudinal seams should be A. One tensile test, one nick break test and completed before beginning the two side bends circumferential welds B.
Two tensile tests, two nick break tests D. The weld sequencing is not important and two side bends E. Related or by a combination of these processes using a manual, semi- automatic, or Fill Api Download, download blank or editable online. Sign, fax and printable Form Popularity api pdf free download form. Fill Online. At the discretion of the company, additional types and number of tests may be required.
When the production welding procedure was qualified with Charpy impact testing, Charpy impact testing shall also be performed to qualify partial thickness and full thickness repair procedures. As noted in Table 5, when wall thickness is over 0. NOTE Dependent on pipe material or welding process, the company may require additional cooling time prior to destructive and nondestructive testing.
The time delay specified in The addition or change in the interpass temperature requirements used to weld the test joint. The repair procedure shall be qualified in the fixed position on a segment of a full- circumference test weld for each repair type to be qualified in the location s specified by the company.
The repair weld shall be a minimum of 8 in. A single test joint may be used to qualify more than one type of repair procedure. Details for each repair procedure shall be recorded with the complete results and circumferential location of each repair. Qualification of repair procedures may be required in the presence of the company.
Weld reinforcement on tensile test specimens shall not be removed for cover pass repairs. The use of optical devices or dye penetrants is not necessary. Any defects shall be within the applicable individual size limits specified in Section 9. If a cross section shows defects that are not associated with the repair weld portion of the completed weld, an additional cross section shall be evaluated.
If the additional cross section contains other defects, the qualification test is unacceptable. The minimum required number of indentations shall be made using a Vickers indenter and a kg load, or less at locations shown in Figure 21 through Figure 26, or made at locations otherwise specified at the discretion of the company. If subsequent repairs e. Maximum hardness values for repair welds shall not exceed those given in Table 6 unless otherwise specified by the company.
NOTE When hardness testing is required, chemical analysis is performed to determine the carbon equivalent of the base materials. Each test of weld metal or HAZ shall consist of at least three valid specimen tests performed at or below the minimum design temperature. The exact size of the specimens depends on the weld thickness but the largest possible size shall be selected. The notch shall be oriented in the through- thickness direction.
The welder shall be qualified according to the requirements of 6. When a repair procedure is required by Welders shall be qualified using a completed weld to make a repair weld following all the details of the repair procedure. The repair weld shall be deposited in the fixed position on a segment of a full-circumference test weld for each repair type to be qualified in the location s specified by the company.
A single completed weld may be used to qualify more than one type of repair. Details of the repair welder qualification shall be recorded and maintained with the complete results of the qualification test for each type and location of repair to meet the requirements of 6. The destructive testing requirements in 6. The total number of specimens and the test to which each shall be submitted are shown in Table 7.
As noted in Table 7, when wall thickness is over 0. A welder who fails to pass the repair welder qualification test s shall be permitted to retest as described in 6. If any of the following essential variables are changed, the repair welder using a repair procedure shall be requalified: a any change from one repair type to another, except when changing from a full thickness repair to any partial thickness repair; b a change in filler metal group see Table 1 ; c an increase in depth of the repair area greater than two times the deposited repair weld thickness in the repair welder qualification test; d a change in position from that for which the repair welder has already qualified e.
Inspection of repairs shall be performed as specified by the company. Welding inspection personnel shall meet the requirements of 8. Repairs shall be documented and maintained by the company. Visual inspection is considered adequate when the defect was rejected by visual means and repaired by grinding without additional welding.
Repairs shall be considered acceptable when the repair area meets the standards of acceptability of Section 9 or more stringent acceptance criteria specified by the company. Repair of the total length of defect s rejected by Annex A alternative acceptance criteria is required. A partial length repair of a defect is prohibited. A detailed procedure for the production of images shall be established and recorded. Radiographic film produced by the use of this procedure shall have the density see Images produced by other systems shall have the requisite sensitivity to define clearly the essential wire diameter of the proper image quality indicator IQI.
The following criteria shall be used to evaluate images: a an acceptable image quality that is free from fog and from processing irregularities that could mask the image of actual imperfections, b the prescribed IQI and the essential wire diameter, c a satisfactory identification system, d an acceptable technique and setup, e compatibility with acceptance standards. All requirements that refer to the quality of the resulting images shall apply equally to X-rays and gamma rays.
The use of radiographic testing and the frequency of its use shall be at the option of the company. The company and the radiographic contractor should agree on the radiographic procedure or procedures to be used prior to the performance of production radiography.
The company shall require the contractor to demonstrate that the proposed procedures produce acceptable images and shall require the contractor to use such procedures for production radiography. A copy of the record shall be furnished to the company for its records.
The record may be in the form of writing, a sketch, or both. As a minimum, each procedure shall include the applicable details listed in For multiple-film techniques, the way in which the film is to be viewed shall be specified. When the OD of the piping containing the weld is 3. When smaller diameter, thicker wall pipe is radiographed, additional exposures should be made to minimize the distortion of imperfection images at the ends of the radiographs.
The IQI shall be made of a material that is radiographically similar to the material being welded. At the option of the company, smaller wire diameter IQI than those specified above may be used, provided the required radiographic sensitivity is obtained.
The image of the essential wire diameter shall appear clearly across the entire area of interest. One shall be within 1 in. When the film length to be interpreted is 5 in. When a repaired weld is radiographed, an additional IQI shall be placed across each repaired area. Separate blocks shall be made of the same or radiographically similar material and may be used to facilitate IQI positioning.
The thickness of the separate block material should be the same as the thickness of the weld. The IQI may be placed above the surface of the pipe or held in position between the surface of the pipe and the imager by a fixture attached to the imager or scanning device.
Acceptability of such IQI placement shall be demonstrated during procedure qualification. Radiographers shall report to the company all defects observed in the images unless the company requires that all imperfections observed be reported. The radiographer shall indicate whether the weld meets the requirements of Section 9. The company shall determine the final disposition of the weld.
The company may specify the identification procedure to be used. Whenever more than one image is used to inspect a weld, identification markers shall appear on each image and adjacent images shall overlap. The last reference marker on each end of the image shall appear on the appropriate adjacent images in a way that establishes that no part of the weld has been omitted.
If any question arises about the condition of the unexposed film, sheets from the front and back of each package or a length of film equal to the circumference of each original roll shall be processed in the normal manner without exposure to light or radiation. If the processed film shows fog, the entire box or roll from which the test film was removed shall be discarded, unless additional tests prove that the remaining film in the box or roll is free from preexposure fog exceeding 0.
It shall be equipped to prevent light, coming from around the outer edge of the radiograph or through low density portions of the radiograph, from interfering with interpretations. The protection and monitoring shall comply with applicable federal, state, and local regulations. The company and the NDT contractor should agree on the magnetic particle testing procedure or procedures prior to the performance of production testing.
The company shall require the contractor to demonstrate that the proposed procedures will produce acceptable results and shall require the contractor to use such procedures for production testing.
The company and the NDT contractor should agree on the liquid penetrant testing procedure or procedures prior to the performance of production testing. The use of ultrasonic testing and the scope of its use shall be at the option of the company.
The company and the ultrasonic contractor should agree on the ultrasonic procedures before the performance of production testing. The company shall require the ultrasonic contractor to demonstrate the proposed procedures to produce acceptable and accurate results and shall require the contractor to use such procedures for production testing.
Caution is advised when this method is applied to in-service weld inspection due to potential parent material and surface imperfections that can interfere with the use of the ultrasonic technique. All surfaces to be ultrasonically scanned shall be in the uncoated condition. For new construction projects, the coating cutback bare pipe length at pipe ends necessary for ultrasonic scanning should be specified prior to the pipe being coated.
Pipe seams should be ground flush with the pipe surface for the distance necessary for ultrasonic scanning. The record shall be in the form of both writing and sketches. The ultrasonic testing personnel shall perform examinations in accordance with qualified and approved procedures see Personnel responsible for testing shall be capable of determining the acceptability of circumferential butt welds in accordance with the acceptance criteria as listed in 9.
The company has the right, at any time, to require personnel to demonstrate their capabilities to perform to the requirements of the qualified procedure. A procedure demonstration report shall be generated and the results documented prior to use on actual field welds.
The demonstration process shall be as follows. Changes in wall thickness, bevel design, acoustic velocity, welding process, repair welds, and other variables that can have an effect on the detectability and resolution of the system shall require additional demonstration welds from other corresponding approved welding procedures. Welder qualification welds may be used. Differences in detectability and resolution between ultrasonics and radiography shall be noted.
If required by the company, destructive testing of the weld sample shall be made to discover or confirm the results. In addition, the procedure shall accurately determine the acceptability of welds in accordance with the criteria listed in 9.
The reference standard shall also be used to determine the actual sound beam velocity, refracted angle, and sound path distance in the pipe material to be inspected. Unknown velocity and refracted angle shall be determined when welds in pipe of different chemistry specifications, wall thickness, diameter or from more than one pipe and rolling or piercing manufacturer are to be inspected. This may be accomplished by using two probes of the same nominal angle and frequency with the probes directed toward one another see Figure When a difference is noted in velocity, angle, or sound path distance, another reference standard shall be made from the different pipe material.
For automated ultrasonic testing and when required by the company for manual ultrasonic testing, flat bottom holes shall be machined into a sample of the pipe to be inspected. This sample shall be used as calibration reflectors in addition to the N10 notches at the inside and outside surfaces. The diameter of each flat bottom hole should be approximately equal to the thickness of one welding fill pass. The flat reflecting surface of each hole shall be installed at the same angle and position as the weld joint preparation for each fill pass required by the welding procedure.
Additionally, planar reflectors or flat bottom holes shall be installed at the weld centerline position with their flat reflecting surfaces vertical to the weld. All reflectors should be spaced apart so that no two will be within the beam spread of one probe simultaneously. For testing on other than new construction, a pipe sample of the same grade, wall thickness, and OD as the pipe to be inspected shall be used to make the reference standard.
A transfer technique using probes of the same nominal angles and frequencies to be used for inspection shall be carried out to determine actual full skip distance, actual refracted angle, and attenuation in the material to be inspected see Figure All interfering partial and full beam reflectors shall be noted datum location and distance from the weld edge and recorded on the examination record. The company may elect to waive this requirement in lieu of lamination checks performed by the mill.
Verify that the outside notch echo peak is at or near zero depth reading. This will establish that refracted angle and velocity settings are sufficiently accurate. Automated ultrasonic testing of the parent material shall be performed by using the same calibration method and evaluation level as that used for manual compression wave or by a different technique if demonstrated to be equal to or better than the manual method.
Measure the surface distance between the transducer exit points. Half the surface distance divided by measured wall thickness equals the refracted angle tangent. Without changing instrument settings, repeat this process on pipe with unknown velocity, refracted angle, and attenuation to determine any differences.
Figure 29—Transfer Procedure After the reference sensitivity, scanning sensitivity, and evaluation sensitivity and levels have been established, they shall be qualified and then incorporated into the final procedure and in the final qualification report.
Evaluation sensitivity should be the same as scanning sensitivity. Other automated techniques, reference reflectors, reference sensitivities, scanning sensitivities, evaluation sensitivities, and evaluation levels may be used if demonstrated to be equivalent to the pulse-echo technique for the detection and evaluation of weld imperfections. Two pipe lengths, full joints or nipples, shall be joined by following all the details of the welding procedure specification.
The quality of the weld shall be determined by both destructive and nondestructive testing and shall meet the requirements of 5. Should a welding procedure qualification utilize a manual weld or semiautomatic pass as outlined in These procedures shall be adhered to except where a change is specifically authorized by the company, as provided for in This record shall show complete results of the procedure qualification test.
This record shall be maintained as long as the procedure is in use. This shall include the type of welding technology and a description of the equipment to be utilized. Materials may be grouped see 5. V or U , the angle of bevel, and the size of the root face and root opening. If a backup is used, the type shall be designated. These may include the location and angle of arc for submerged arc welding, the contact-tube-to-work distance, and the oscillation width and frequency.
Changes other than those listed in NOTE The groupings specified above in Changes in filler metal may be made within the groups specified in An increase or decrease in the range of flow rates established for the shielding gas also constitutes an essential variable. A change in the method of cooling after welding resulting in a higher rate of cooling also requires requalification of the welding procedure.
The completed weld shall be tested by destructive methods, nondestructive methods, or both, and shall meet the requirements of 6. Should a welding procedure qualification utilize a manual or semiautomatic pass as outlined in The tensile strength tests shall not be replaced by nick break tests see 6.
Prior to the start of welding, each welding operator shall have received adequate training in the operation of the welding equipment. If the welding procedure involves more than one operation, welding operators shall be qualified on the type of welding equipment that will be used in production welding. Changes in the essential variables described in Welders shall be qualified if all tests are acceptable. This form should be developed to suit the needs of the company but must be sufficiently detailed to demonstrate that the qualification test meets the requirements of this standard.
A list of qualified operators and the procedures for which they are qualified shall be maintained. An operator may be required to requalify if a question arises about their competence. At least two welds shall be made by joining pipe lengths, full joints, or nipples and by following all the details of the welding procedure specification.
The quality of the weld shall be determined by both destructive and nondestructive testing and shall meet the requirements of The minimum number of specimens and the tests to which they are to be subjected are given in Table These specimens shall be prepared and tested as specified in If the specimen breaks in the weld or fusion zone, the observed strength is greater than or equal to the SMTS of the parent metal, and the weld meets the requirements for soundness given in The sides of the specimen shall be macroetched to locate the fusion line.
Edges of the specimen shall be smooth and parallel. Nick Break Test Specimen This record shall show complete results of the procedure qualification test and shall be maintained as long as the procedure is in use. Changes other than those given in The completed weld shall be tested by both radiographic and mechanical test methods, as specified in Each operator shall have received adequate training in the operation of the equipment prior to the start of welding and shall be thoroughly familiar with the equipment they operate.
The frequency of such additional inspections and tests shall be as specified by the company. If any of the welding parameters deviate beyond the tolerances specified in the welding procedure specification, the weld shall be unacceptable.
If the strip chart is found to be unacceptable after welding has been completed, the joint shall be rejected and removed from the line. Other nondestructive tests may also be required by the company. Each production weld shall meet the requirements of The heat treatment cycle shall be documented using a strip chart recorder, and any deviation beyond the ranges specified for heating time, maximum temperature, or cooling rate shall be cause for reheat treatment.
Repair by welding is permitted only by agreement with the company. Such criteria have provided an excellent record of reliability in pipeline service for many years. The use of fracture mechanics analysis and fitness-for-purpose criteria for determining acceptance criteria is an alternative method and incorporates the evaluation of both imperfection height and imperfection length.
Typically, but not always, the fitness-for-purpose criteria provide more generous allowable imperfection length. Additional qualification tests, stress analysis, and inspection are required to use the fitness-for-purpose criteria. Performing analysis based on the principles of fitness-for-purpose is alternatively termed engineering critical assessment, or ECA. The fitness-for-purpose criteria in the prior versions of this annex required a minimum crack tip opening displacement CTOD toughness of either 0.
Improvements in welding consumables and with more precise welding procedures, especially, with the increased use of mechanized welding devices have resulted in higher and more uniform toughness and ductility in most welds.
At the same time, toughness values below 0. Welds with CTOD toughness below 0. The acceptance criteria are revised so that they are commensurate with the measured toughness and applied load levels. This annex includes three options for the determination of acceptance limits of planar imperfections.
In numerical order, the options are increasingly complex in application but offer wider range of applicability. Option 1 provides the simplest methodology. Option 2 allows for the full utilization of the toughness of the materials thus providing a more accurate criterion but requires more calculation. The first two options were developed with a single set of underlying procedures but are limited to applications with a low to moderate fatigue loading as described in A.
Option 3 is not prescriptive, and its consistency could be significantly less than Options 1 and 2. Option 3 should only be exercised, when necessary, by skilled practitioners with demonstrated knowledge of fracture mechanics and pipeline load analysis. DRM is included at the request of the publisher, as it helps them protect their copyright by restricting file sharing. Visit FileOpen to see the full list. This standard covers the gas and arc welding of butt, fillet, and socket welds in carbon and low-alloy steel piping used in the compression, pumping, and transmission of crude petroleum, petroleum products, fuel gases, carbon dioxide, and nitrogen, and, where applicable, covers welding on distribution systems.
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