2Codes and Standards Learning Activities Read Handbook 412-464 View Slides;Read Notes,Listen to lectureDo on-line workbookDo homeworkLesson ObjectivesWhen you finish this lesson you will understand:Codes and Standards and Standards Writing BodiesWelding Procedure Development and QualificationsKeywordsCodes, Specifications, Recommended Practices, Guides, Classifications, Methods, ANSI, ISO, Welding Procedure Specification (WPS), Procedure Qualification Record (PQR), Welder Performance Qualification
3IntroductionTypes of StandardsCodes are generally applicable to processes and indicate the mandatory use of materials or actionsSpecifications are generally associated with a product and indicate the mandatory use of materials or actionsRecommended practices and guides are offered primarily as aids to the userClassifications and methods provide lists of established practices or categories for processes or productsShall/willShould/mayThere are a number of different types of standards that are generally written by consensus standards writing bodies. These bodies are made up of volunteers who are experts in the field and represent all facets of the industry. The standards are written and presented for public review and vote so that they truly become the best consensus documents with wide expertise. These standards fall into 6 major categories: Codes are generally associated with a process and they spell out MANDATORY use of materials or actions. Specifications likewise are mandatory but they are generally associated with a product. Recommended practices and guides are documents offered as an aid to the practitioner to help in manufacturing. Classification and methods provide lists of established practices or products.T
4Code Writing Agencies This Table is in the Welding Handbook Above is a table of code writing bodies and their addresses presented here for your future reference. This table in larger size is available in the Welding Handbook. As a practicing engineer you will want to get to know what areas of welding expertise each of these standards writing bodies represent. You may also want to participate on the groups and subgroups who write the standards. This is an excellent way of participating in the industry for the benefit of the industry. Just write and volunteer.
5What is Covered by Standards IntroductionWhat is Covered by StandardsProductsPiping - American Petroleum InstituteFiller metals - American Welding SocietyShips - American Bureau of ShippingPressure vessels and boilers - American Society of Mechanical EngineersBridges - American Institute of Steel ConstructionHealth & SafetyTerminologyTesting ProceduresAs we have already seen, there is a whole variety of things that are coved by standards including products and consumables used to make products, manufacturing processes, health and safety concerns in the workplace, terminology so that all engineers talk the same language, and even testing procedures to confirm the quality of the manufactured product as we discussed in the last module. Each standards writing body takes responsibility for these items within their own sector of the industry.T
6In some cases, a single standards writing body may have standards which are applicable to a wide variety of products such as the American Welding Society (AWS) listed above. In other cases, the applicable standards may reside in very few standards writing bodies. This table give you a feeling for responsibilities and overlap.
7American National Standards Institute (ANSI) IntroductionAmerican National Standards Institute (ANSI)Coordinating organization for the U.S. voluntary standards systemThere are approximately 10,000 American National Standards, which encompass nearly every field and disciplineANSI standards are developed and used voluntarily; they become mandatory when adopted or referenced by a governmental bodyIn recent years, an organization called the American National Standards Institute (ANSI) has been attempting to coordinate all these standards and writing bodies. This is helping to reduce overlap of responsibilities. The standards thus generated are used by individual manufacturers on a voluntary basis unless they a specifically stated in the terms of a contractual agreement or when adopted by a governmental agency. In a contract, the year of issue of the standard is referenced and that becomes the official workmanship standard for the part even if the standard is subsequently updated, unless the contract is amended to the new update. A second organization the International Organization for Standardization (ISO) has also been established. The purpose of this organization is to promote uniform international trade.International Organization for Standardization (ISO)Establishment of Uniform Standards for International TradeT
8International Organization for Standards (ISO) Professional Society StandardsInternational Organization for Standards (ISO)80 countries, standards, ANSI is the U.S. representativeISO (ANSI/ASQC Q90) is a series of quality management and assurance standards in manufacturingDesigned for manufacturing sectorEC has adopted ISO 9000 and prefers US suppliers that are ISO 9000 certifiedDoD, DuPont, 3M, AT&T are asking suppliers to comply with ISO 9000ISO Factors to be Considered When Assessing Firms Using Welding as a Prime Means of FabricationOver 80 countries have agreed to use the over 4000 universal stands supported by ISO. This makes international trade much easier than before this organization was in existence. One of the most popular ISO standards are the 9000 series which deal with the production of quality parts. You will hear more about this series of standards later in the welding engineering curriculum.T
9Health & Safety ANSI/ASC Z49.1-1988 Safety in Welding and Cutting Health and SafetyHealth & SafetyANSI/ASC Z Safety in Welding and CuttingIncluded in the General Industry Standards of OSHASpecifically covers arc, oxyfuel gas, resistance weldingHealth and Safety in Welding and Allied Processes 4th edition, ed. N.C. Balchin and H. R. Castner, McGraw-Hill Inc. 1993A more or less universal code for health and safety has been issued by ANSI and it bears mentioning separately because of the paramount importance of this subject. It is ANSI Z49.1 Code. A second source of safety and health information which you might want to consider reading is the Balchin and Castner book listed above.T
10American Welding Society (AWS) Standards Professional Society StandardsAmerican Welding Society (AWS) StandardsDefinitions and Symbols (A)Filler Metals (A5)Qualification and Testing (B, C, and D)Welding Processes (C)Welding Applications (D)The American Welding Society is one of the most important code writing bodies that you as a welding engineer will need to have some experience with. AWS divides is standards into several categories which they designate with a letter code as illustrated above. Thus the D1.1 Structural Welding Code falls under a welding application type standard.T
11Definitions and Symbols Professional Society StandardsDefinitions and SymbolsANSI/AWS A2.4 Symbols for Welding, Brazing, and Nondestructive ExaminationCommunication between designers and fabricatorsJoint geometry, weld contour, surface finishANSI/AWS A3.0 Standard Welding Terms and DefinitionsStandard terms for use in written and oral communication conveying materials joining informationNon-standard termsThe AWS A2.4 welding symbols standard you have already seen when we reviewed the welding symbol module, and the A3.0 terms and definitions we have have been using all course long. These two standards in particular allow engineers to talk to each other without confusion and you should get in the practice of using proper terms and symbols.T
12ANSI/AWS D1.1 Structural Welding Code: Steel Professional Society StandardsANSI/AWS D1.1 Structural Welding Code: SteelGuidelines for design of welded joints as well as prequalified joint geometriesStatically loaded structuresDynamically loaded structuresTubular sectionsDetails the processes used with particular jointsHow to qualify welding procedures and personnelOutlines quality and inspection in welded constructionFiller metal recommendationsThe D1.1 structural welding Code for Steels is another of the most quoted standards. Note that it give information about processes and joints, about qualification procedures, about inspection and about filler metal requirements. One of the most important parts is the extensive listing of prequalified joint geometries. This saves the practicing engineer considerable amount of time in that he/she does not have to run a bank of joint qualification tests for every new weld. Please take some time to skim through the D1.1 Code in the Library.T
13AWS D1.1 Prequalified Joint Design Professional Society StandardsAWS D1.1 Prequalified Joint DesignHere is an example of one of the prequalified joints listed in the D1.1 Code. Note that all the information about how to make acceptable welds with several different welding processes are presented here for this particular joint geometry.T
14ASTM (American Society for Testing and Materials) Professional Society StandardsASTM (American Society for Testing and Materials)Specifications cover virtually all materials used in industry and commerce, but not welding consumablesAnnual Book of ASTM Standards, 15 sections (65 volumes)1 - Iron and Steel2 - Non-ferrous3 - Metal test methods and analytical proceduresSpecification of groups of similar steel (A)A36 - general construction steelsA387 - chromium-molybdenum steel for elevated-temperature service in piping and pressure vessel systemsASTM maintains the responsibility for the specification and testing proceducres for all types of materials (metals, ceramic, organic, glass, etc.). They have 65 volumes of standards for all of these materials. The three most often used by welding engineers are the Iron and Steel volume, the non-ferrous volume and the volume on test methods.T
15American Society of Mechanical Engineers (ASME) Professional Society StandardsAmerican Society of Mechanical Engineers (ASME)Boiler and Pressure Vessel Code has 11 sections and is referenced by most states, major cities in the U.S., Canadian provinces, a number of federal agenciesBefore fabricating a boiler or pressure vessel, a company must have a quality control system and a manual describing itASME issues a Certificate of Authorization and a code symbol stampUnique in that it required 3rd party inspection independent of fabricator and userUses same steel designations as ASTMThe boiler and pressure vessel code of the American Society of Mechanical Engineers is another of the most used sources of welding procedures. Updates to this code in all 11 volumes are issued often and engineers responsible for pressure vessel manufacture must maintain an awareness of these changes. Often problems found in the field or on the shop floor are submitted to ASME as “code cases” which will get a thorough investigation by the code body and decisions rendered. Many of these result in changes to the code.T
16Boiler and Pressure Vessel Code Professional Society StandardsBoiler and Pressure Vessel CodeSection II- Materials Specifications for base metals, filler metals, fluxesSection V - Nondestructive ExaminationSection IX - Welding and Brazing Qualifications for personnel and proceduresDelineates a P number grouping of steels for the purpose of welding qualificationP1 - carbon-manganese steels with a minimum UTS of ksiP5 - alloy steels with % chromium, <10% total alloyAll steels within a P number can be welded with the same procedureThe section of the Pressure Vessel Code most often used by welding engineers are listed above.T
17Professional Society Standards Other StandardsAmerican Petroleum Institute (API) Standard Welding of Pipelines and Related FacilitiesQualifications of Welding Procedures and WeldersInspection and nondestructive testingRepair and removal of defectsUnified Numbering System (UNS)Cross references the numbering systems from different countriesOver 3500 metals, alloys, and filler metalsDesignated SAE HSJ1086 / ASTM DS56The API 1104 for welding of pipelines is a third most popular welding code. When candidates for certification as welding inspectors take their written exam, they usually specify one of the three codes listed:AWS D1.1 Structural Welding CodeASME Pressure Vessel Code, orAPI 1104.T
18Turn to the person sitting next to you and discuss (1 min.): What does being a “third party consensus standards writing body” mean?
19Qualification & Certification We have been mentioning the qualification and certification of welding procedures and welding personnel above, but now let’s take a look at the procedures set up by the standards to perform these qualifications and certifications.
20Welding Procedure Specification (WPS) A document that provides in detail required weldingconditions for a specific application.Procedure Qualification Record (PQR)A record of actual welding conditions used to produce anacceptable test joint and the results of the qualification tests.The system to do these qualifications and certifications have three major parts. They are:the procedure qualification recoded (PQR) which is a written record of the weld procedure and the tests performed on the weld to ascertain that the procedure did indeed produce an acceptable weld.The welding procedure specification (WPS) which is the document detailing the proper procedure and required welding conditions to make the weld. The WPS is the document often giving to the welder who is told to reproduce this procedure in the welds performed.The welder performance qualification and certification is record of the test given to the welder which proves that the welder is capable of making quality welds. It does not guarantee that the welder will make perfect welds each weld but certifies that the welder is capable of doing quality work. Thus final weld inspection should not be ignored in any quality weldment production.Welder Performance Qualification-CertificationA record of a welder’s or welding operator’s ability to producewelded joints that meet prescribed standards
21The list of standards above are some of the standards which require qualifications and certifications as part of their standard operating procedures.
22Pre-Qualified Procedures (Some Codes Permit - Example AWS D1.1 Code)Based on the reliability of certain proven proceduresspelled out by the applicable code or specificationUse Written Procedures From CodeAll Essential Variable SpecifiedWeld Qualification Tests Not RequiredEmployer Accepts Responsibility for UseDeviations Negate Prequalified StatusWe have mentioned pre-qualified Procedures in the past. As seen above, when the welding engineer is using a pre-qualified procedure, all the essential variables are specified and the engineer can just accept the procedure without any qualification testing required. HOWEVER, if there is any variation in variables as specified, a re-qualification testing program may be required also.
23Basic Steps in Qualification of a Procedure 1. Prepare a preliminary WPS2. Prepare and weld a suitable test weldment using WPS3. Conduct required NDT and Destructive Tests4. Evaluate Results of prep, welding, testing5. Document results on PQR6. Issue approved PQR7. Issue approved WPSList above are the basic steps needed to qualify a new or modified procedure. Note the amount of effort required to come up with a candidate WPS, make welds to test that candidate, test the welds made and record the results, all before issuing an approve WPS. Note also, that a qualified welding engineer is usually held responsible for performing all these steps to the “letter of the law” and then issuing the approved WPS.
24PQR - WPS Variables Considered Base MetalWelding ProcessFiller MetalType of Current/RangeVoltageHeat InputTravel SpeedJoint Design and TolerancesJoint and Surface PrepTack Weld/Grind Off?Welding DetailsElectrode SizePassesWeavePosition *Preheat and InterpassPeeningSecond Side PrepPost Weld Heat TreatRecords (If Required)The variable usually considered and recorded in the PQR and WPS are listed above. Some of these may vary code to code, so be careful when issuing the approved WPS.Check Specific Code for List of Essential Variables(Essential Variable Must Be Included in the WPS)
25Position is one of the essential variable almost always specified because of the varying degree of difficulty in making welds in some positions when compared to others. Often, a welder who qualifies in the harder positions is allowed to make welds in the less difficult positions, but again check the specific code being used rather than assuming.
26Note for pipes, rotation in some cases is allowed thus the positions have an additional qualifier
27PQRPage 1This is an example of the front page of a typical PQR. Note the degree of specification listed for the way the weld was made.
28PQRPage 2The back page of that PQR lists the result of the destructive and non-destructive test run on the weld made to determine that indeed the front page welding conditions resulted in an acceptable weld. If defects are found in this weld, it is either the problem with the conditions set to make the weld or the ability of the particular welder making the weld. It is advantageous to use your best welder for these tests. A defect required that the weld be remade or a different set of weld parameters be tried.
29Tests Commonly Used for PQR’s The type of destructive and NDE test used to test the welds made and recorded in a PQR are listed above. Some codes require certain types of these test, other make some optional.
30WPSOnce an acceptable PQR has been recorded, the welding engineer can issue a Welding Procedure Specification (WPS) using the welding conditions documented in the PQR. DO NOT DISCARD THE PQR. You might need the results of the tests recorded in the PQR to prove that you did do the testing in case of a dispute or a law suit.
31Welder Performance Qualification Duration Of Qualification VariablesWelding ProcessFiller MetalPositionJoint DetailsThicknessTechnique(Qualifying in a more difficult positionmay qualify in an easier position)This brings us to the last step, that of qualifying and certifying the competence of the welder. The important variables are listed above. If the welder is asked to weld with one of these variables differing from the condition under which he/she took the qualification test, a re-test may be required. (See the specific code under which your company is working). A welder who has qualified stays qualified for some limited amount of time (usually on the order of months) if that welder has not made welds with those exact variable during that time. Again check the code for time limits on certification.Duration Of QualificationDependent upon Code(Usually inactivity of 3 to 6 months required requalification)
32Performance Qualification Record This is a sample of a performance qualification record for a welder. Note that each welder may have many such records depending on how many variations of conditions he/she has tested under. Also, a Performance record should be maintained for each welder on your payroll. Computer programs to keep track of welder performance qualifications are available and often help in large operations.
33Above is listed variable which when they are changed may require a redo in procedure or performance qualifications.
34Run the “Welding Procedure Specification” from the “Demonstration Page” of the WE300 Web Page