THE PRACTICAL REFERENCE GUIDE for WELDING INSPECTION MANAGEMENTTed visual inspection of pressure vessels and pressure piping

visual inspection

~ S T D * A W S P R G V T - E N G L 1777 ~ E 07842b5 0539375 T LI American Welding Society @ The Practical Reference Guide for Visual Inspection of Pressure Vessels and Pressure Piping ``,``-`-`,,`,,`,`,,` - Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale STDmAWS PRGVT-ENGL 1999 0784265 051937b 396 E THE PRACTICAL REFERENCE GUIDE for WELDING INSPECTION MANAGEMENTVisual Inspection of Pressure Vessels and Pressure Piping Ted V Weber Principal Consultant Weber & Associates ``,``-`-`,,`,,`,`,,` - This publication is designed to provide information in regard to the subject matter covered It is made available with the understanding that the publisher is not engaged in the rendering of professional advice Reliance upon the information contained in this document should not be undertaken without an independent verification of its application for a particular use The publisher is not responsible for loss or damage resulting from use of this publication This document is not a consensus standard Users should refer to the applicable standards for their particular application American Welding Society 550 N.W LeJeune Road, Miami, Florida 33126 Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale STD-AWS PRGVT-ENGL 1999 W 0784265 0539377 222 AUTHOR NOTES Visual inspection (VT) is one of the more important inspection methods used to ensure the quality of both new fabrication, as well as equipment and piping after some period of service It is used in all industries, and should be considered as the basic inspection method prior to the selection of any other inspection method A phrase that puts VT in the proper perspective follows: “lt has been shown repeatedly that an efective program o visual inspection, conducted by properly trained personnel, f will result in the discovery o the vast majority of those defects which would otherwise be discovered later by some more f expensive nondestructive test method.” Note the emphasis on proper training; without such training, the inspector often only looks at things without actually inspecting them, and critical discontinuities are often overlooked It is to that end, the training of visual inspectors, that this Guide was prepared Proper visual inspection requires inspector training in many disciplines and the training should be a continuous, ongoing process New technologies useful to visual inspection are continuing to be developed, and these must be incorporated into the overall inspection efforts to optimize results It was once stated that, “lnspectors must have been haEfcrazy to have selected inspection as a lifetime career!” While many of us may agree with that statement in part, most would agree that inspection is a very challenging and catisQing career path, and we remain quite proud to be called inspectors Ted V Weber Hendersonville, Tennessee Photocopy Rights Authorization to photocopy items for internal, personal, or educational classroom use only, or the internal, personal, or educational classroom use only of specific clients, is granted by the American Welding Society (AWS) provided that the appropriate fee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, Tel: 978-750-8400;online: http: //www.copyright.com O 1999 by the American Welding Society All rights reserved Printed in the United States of America ``,``-`-`,,`,,`,`,,` - Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale ~ STD-AWS PRGVT-ENGL 1999 ~~ W 0784265 0519378 Lb9 m TABLE OF CONTENTS Page No Introduction New Fabrication Base Metals and Filler Metais Welding Procedure Qualification Personnel Qualification Inspection Planning Repairs and Re-inspection Production Welding-New Fabrication Fabrication Codes In-Service Inspection Annex A-Technical and Scientific Organizations Annex -1998 ACME Boiler and Pressure Vessel Code Sections Annex C-Discontinuities Annex &Selected References ``,``-`-`,,`,,`,`,,` - Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS iii Not for Resale 10 12 14 19 22 23 28 S T D - A W S PRGVT-ENGL 2999 = 0784265 0529379 OT5 E Introduction In one version of a perfect world of manufacturing, there are no inspectors None are needed because each and every person in the workforce has been so thoroughly trained, possesses and applies all the necessary personal attributes, and is paid a reasonable salary such that all manufacturing mistakes are completely eliminated Think of that perfect scenario: a manufacturing world without mistakes Some of today's quality approaches reach for that ideal goal and have developed precepts that considerably reduce online inspection requirements The concept of "continuous improvement" is an important part of that quest for perfection, and is found in many quality-concept documents One approach to quality is found in the documents, modified by American organizations, commonly referred to as IS0 Standards These often become the basis for "IS0 Certification," which many manufacturing sites obtain and market as part of their these IC0 quality proquality program In the U.S., gram standards and guides are published under the combined authority of ANSI (American National Standards Institute), IS0 (International Organization for Standards), and the ASQ (American Society for Quality), as "Q" documents Two of these are Q9004-1, Quality Management and Quality System Elements-Guidelines, and Q9001, Quality Systems- Model for Quality Assurance in Design, Development, Production, installation, and Servicing (see Figure 1) A thorough understanding of these two quality documents is very helpful in organizing a Quality Assurance program for fabrication companies Additional ASQ documents covering fabrication quality are Q9002, Quality Systems-Model for Quality Assurance in Production, installation, and Servicing, and Q9003, Quality Systems-Model for Quality Assurance in Final inspection andTest Their cost is minimal and can be obtained from the American Society for Quality, 611 East Wisconsin Avenue, Milwaukee, WI 53202 However, as much as these new quality programs have improved quality in many areas, in our lessthan-ideal, real world, there still remains a need for skilled inspectors Most have seen various versions of the old saying, "People whaf you inspect, not what you expect." While that statement appears to be quite cynical, many critical manufacturing efforts still follow that credo with great success Inspection will continue to be a necessary skill for AMERICAN NATIONAL STANDARD AMERICAN S U FMI QUAUTY O M 611 EAST W6co" AMNUE MLWMJKEE.WISCONCIN 5u202 Figure ANSVISO/ASQC Q9001-1994 decades to come, especially in the fabricating industries, and visual inspection will certainly continue on the front line of that inspection effort In the broad field of Quality Assurance, the control of welding operations and fabrication of process equipment encompasses many technical disciplines including engineering design, materials selection, welding processes, welding procedures, nondestructive inspection, and corrosion mechanisms Visual inspection plays an important role in all of these and it requires proper training of personnel to provide the necessary function of quality control at each stage of fabrication as well as continued inspections during the life of the component Inspector certification programs, such as the AWS CWI and SCWI certifications, have been developed to ensure a basic minimum qualification of the visual inspection personnel (see Figure 2) Other organizations such as the American Petroleum Institute (API), the National Association of Corrosion Engineers (NACE), and the American Society for Nondestructive Testing (ASNT),have developed AWS Practical Reference Guide ``,``-`-`,,`,,`,`,,` - Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale Slang terms and incorrect terminology often lead to confusion and errors So, a second requirement is to know and understand the proper terminology pertinent to a given industry Proper terminology includes the mechanical aspects of stress, strain, strength, ductility and many others that aid in describing the mechanical properties of the materials used in manufacture It also includes the necessary terminology of welding and fabrication processes, including joint and weld geometry and welding processes as well as typical discontinuities Various base and weld metal discontinuity types have been defined by AWS and are described in AWS 81.10, AWS B1.ll, AWS A3.0, and in the convenient AWS publication The Everyday Pocket Handbook for Visual Inspection and Weld Discontinuities-Causes and Remedies (see Figure and Annex D-Selected References) Excerpts from some of these are found in Annex C-Discontinuities Knowledge of corrosion terms is also required when completing in-service inspections of pressure equipment Corrosion terms can also be found in several of the references noted in Annex D-Selected References Figure AWS QC1-96-Standard for AWS Certification of Welding Inspectors certification programs for general and/or specific industries Additionally, several industries and private companies have produced industry-specific or in-house training programs to train the inspectors on their particular needs Nuclear power industries have such programs, as the petroleum, petrochemical, and aerospace industries Visual inspection is learned through experience; almost everyone has the inherent capability to see things, but visual inspection requires a more thorough observance of details that requires considerable training, and the learning curve is usually very experience-intensive.One of the first requirements of a visual inspector in the fabricating realm is to be able to read and interpret engineering drawings Unless the inspector has this first capability, the requirements of the fabrication cannot be properly determined Many inspectors learn blueprint reading in school, either in a drafting or engineering An important third requirement for the visual inspector is a thorough knowledge of the fabrication codes pertaining to the various industries The petroleum industry relies on API specifications, the railroad industry relies on the AAR standards, and building construction relies on the AWS structural codes Almost every industry has specific codes that pertain to their particular needs and the inspector must have access to, and be familiar with, the applicable codes A fourth requirement is precise documentation of inspection results Verbal statements regarding inspections usually have little value; the inspection results must be documented such that they can be referred to months or years later with absolute understanding and clarity With today’s computer technology, there is little or no excuse not to have complete, clear, legible, and retrievable documentation of inspection results readily available as needed Today’s technology also includes the excellent digital cameras that permit photographs of the equipment or condition to be easily inserted into the records Video cameras are another method of AWC Practical Reference Guide Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale ``,``-`-`,,`,,`,`,,` - drawing course; others learn on the job The method of learning to interpret fabrication drawings is not the important issue Rather, it is the interpretation itself that must be included as part of an inspector’s skills STD-AWS PRGVT-ENGL 1999 E 07842b5 0519381 The Everyday Pocket Handbook for Visual Inspection and Weid DiscontinuitiesCauses and Repairs Compiled as a useful tool for on-the-job welding personnel by the AWS Product Development Committee Figure The Everyday Pocket Handbook for Visual Inspection and Weld Discontinuities-Causes and Repairs recording inspection results As one inspector noted, ”in today‘s world, if it’s not written down, it hasn’t happened!” It is certainly recognized that the actual requirements for thorough visual inspection may vary from one industry to another, but all visual inspection contains the four basic requirements noted above that must be met to inspect an item to the desired and required level Inspection not only applies to the original fabrication of the components, but extends to the in-service inspections as weli Fitness for purpose inspections must often continue for the life of the component, and this usually requires some form of periodic inspection, performed to written guidelines, to ensure the continued safe operation of the item Most are somewhat familiar with the stringent rules for continued inspection for aircraft; they receive periodic inspections after a set number of hours of operation Many pressure vessel codes have similar requirements but usually have longer time periods between inspections It is not the purpose of this Guide to repeat in great detail all the visual inspection procedures found in these other documents Rather, practical approaches to the broad topic of visual inspection will be covered, both for new fabrication and in-service inspections The emphasis will be on piping and vessels for pressure containment New Fabrication A good starting point for any new fabrication project is close communication between the manufacturing personnel and the design groups To use a petrochemical process as an example, the manufacturing group knows the task it wants to perform whether it is to manufacture polyester sheeting material, polyethylene pellets for molding machines, or acids to use as ingredients for other manufacturing processes The group conveys its desired result to the design group and after several discussions and iterations, the final design of the component is completed During this design stage, it is very helpful to have input from the welding and metallurgical engineers as well as the inspectors to assist in a design that first of all can be fabricated, and secondly, inspected adequately All too often, designs are too quickly put together only to find out the materials selected pose tremendous difficulty in AWS Practical Reference Guide ``,``-`-`,,`,,`,`,,` - Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale STDmAWS PRGVT-ENGL 1997 0784265 0537382 b7T welding, or the design makes it impossible to thoroughly inspect ``,``-`-`,,`,,`,`,,` - The design of each separate component for a complex process is sometimes done in a rather random fashion For example, a vessel is needed to mix the raw ingredients and is designed by the pressure vessel group Then a distillation column is needed and is designed by the distillation column designers A heat exchanger is needed and is designed by the heat exchanger designer When insufficient communication exists between these various groups, it can lead to costly redesign, or material changes, to incorporate exactly what is needed Figure A typical petrochemical complex showing the complexity and variety of pressure vessels and piping arrangements A far better approach is to have good liaison between the various design sections through a project manager to ensure compatibility of each component, especially regarding the materials of construction and corrosion issues The selection of materials incorporates many different aspects including cost, availability, strength, weldability, and corrosion resistance Selection of the correct material may require fabrication and corrosion testing to ensure suitability Visual inspection of these corrosion tests may be an initial inspection requirement for the project, and requires an understanding and knowledge of the various corrosion tests by the inspector Often these are done to ASTM specifications and the inspector must have ready access to them Pressure containment usually requires the use of welding operations in the manufacturing of the piping and vessels needed In the fabrication of new equipment, the welding operations usually get considerable attention up front There are several reasons for this, but they often include the general lack of knowledge of welding techniques by many of the engineering staff as well as previous experiences with weld failures A list of the initial requirements for fabrication inspection will usually include the following: Base Metals and Filler Metals These should be purchased to specifications listing all the necessary requirements, with a supporting Material Test Report requirement on the purchase order These necessary requirements usually include the mechanical properties, chemistry, size, shape, manufacturing method, surface finish, heat treatment, and quantity Base metals are often ordered to ASTM, ASME, or API specifications; filler metals are usually ordered to AWS specifications Specific items may require additional data, such as the protective coatings for corrosion resistance of steel products or shipping container requirements for low-hydrogen electrodes, and all the materials should always be inspected upon receipt to ensure compliance Often, for critical applications, check analyses on the chemistry or mechanical properties may be made to reflect a higher degree of certainty For filler metals, this may require the preparation of a weld sample to a specification for chemical or mechanical testing, with its preparation witnessed by an inspector Once the proper materials have been received and confirmed, it is imperative that storage of these materials maintains their proper identification (ID) There are many different systems used for maintaining the ID of materials Coding by different paint colors can be an acceptable method for materials control, but consideration should be given to the effects of sun and weather on the color Color changes occur with exposure to sun, and this must be recognized Color changes over time have led to mistakes in alloy identification Weather can also cause deterioration of the materials, and protection may be needed during storage Piping is often ink marked every three or four feet along its length with its specification, grade, heat number, etc., which helps maintain its identification Plate is often stamped or paint marked with its ID on one corner Consider what happens if a portion of the plate is used Often, the corner with the AWS Practical Reference Guide Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS m Not for Resale ~ STD-AWS PRGVT-ENGL 1999 m 07842b5 0539383 52b ``,``-`-`,,`,,`,`,,` - Figure ASME Section II, Part A, covering ferrous material specifications Section II, Part B of the same code covers nonferrous materials Figure ASME Section II, Part Cycovering filler metals The AWS Filler Metal Specifications were adopted for use in Part C marking is taken for use and this requires the remarking of the “drop” or remainder Inspectors should, and often do, play a role in this remarking Other items such as forgings, castings, or subassemblies may require bar coding, stamping, tagging, or segregation to maintain their identity ways depending on the code requirements in effect for the project In some codes, test weldments must be made and tested to qualify a procedure Other codes may permit the use of “canned” welding procedures or the use of mockups The inspector must be familiar with the procedure qualifications and ensure they are met completely and satisfactorily Welding Procedure Qualif ¡cation Once the base materials have been received, confirmed, and stored properly, the next item requiring attention for fabrication of pressure containment equipment is the qualification of welding procedures (This step may be the initial step in the entire process if the fabricator has little or no experience with the materials to be used.) A welding process is selected and a preliminary Welding Procedure Specification is usually prepared However, these procedures can be qualified in several different Two of the more common procedure qualification approaches are those found in the AWS standard B2.1:1998, and the ASME Boiler and Pressure Vessel Code, Section IX (see Figures and 8) Either may be acceptable but if an ASME Code fabrication is being produced, Section IX is required for procedure qualification Too often, once a welding procedure has been qualified, it disappears into the dark corners of some office and is never seen again except during formal audits While a master list of procedures with current copies should be maintained in an office, AWS Practical Reference Guide Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale S T D O A W S PRGVT-ENGL 1779 111 0784265 0519384 4b2 m ANSVAWS ü2.1!1998 An A m o r i m N a ỵ i m l Siandard Specification for Welding Procedure and Performance Figure ASME Section IX also covers qualification of procedures and personnel for welding copies of those welding procedures should also be placed in binders or protected with plastic covers and made readily available at the shop floor to the welding and inspection personnel This simple step often eliminates many procedural mistakes during fabrication The inspector should be familiar with the period of validity for the welder to remain qualified; this period is usually noted in the applicable code Most welder qualifications are valid for a six-month period, meaning that the qualification is valid as long as the welder performs the same welding process to which he or she qualified If a welder does not perform any documented welding with the qualified welding process in the speciried time period, the welder is no longer considered qualified Some companies adhere strictly to the code qualification requirements; other retest their welders once a year regardless of the code requirements or continuing use of the process There are several software programs available that aid the tracking of welder qualifications Central certification of welders is another option that allows a company to maintain records on qualification Independent third party certifications of welders can provide value by in-, troducing rigorous standardized procedures for Personnel Qualification Once the necessary welding procedures have been qualified, the next step is to qualify the welders and welding operators to the applicable code The inspector has a key role to play in this activity; many codes require the witnessing and documentation of both the welder performance tests and the mechanical testing of the resulting welded test specimens by an inspector Most codes and other standards cover both the procedure qualification and the welder performance testing AWS Practical Reference Guide Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale ``,``-`-`,,`,,`,`,,` - Figure ANSVAWS 82.1 :1998 can be used for welding procedure and personnel qualification S T D * A W S PRGVT-ENGL 3999 random spot examinations, and these are defined in ACME B31.3 as follows: 100%-complete examination of all of a specified kind of item in a designated lot m 07642b5 0539392 539 In-Service Inspections Inspecting piping and equipment that has been in service for some period of time presents several unique aspects that must be considered, such as: Random-omplete examination of a percentage of a specified kind of item in a designated lot Which code will be used as the guideline? Spot-a specified partial examination of each of a specified kind of item in a designated lot; e.g., a part of the length of shop-fabricated welds in jacketed pipe Expected corrosion rate, if any Experience history-type pected, if any of deterioration ex- Frequency of inspection needed Random Spot-a specified partial examination of a percentage of a specified kind of item in a designated lot Type of inspection required Decontamination required for internal inspection Plus others aspects As one moves down the list, the amount of inspection given is decreasing ACME B31.3 specifies one of the above inspection categories depending on the fluid service category selected previously by the engineer The three codes often used for in-service inspections of petrochemical and refinery piping and equipment are: It is also helpful to note the separate definitions given for Inspection and Examination Often we mistakenly use these words interchangeably B31.3 defines them as follows: API 510, Pressure Vessel Inspection Code: Mainfe- Inspection applies to functions performed for the owner by the owner’s inspector or the inspector’s delegates An owner’s inspector conducts inspections for the owner Examination applies to quality control functions performed by the manufacturer (for components only), fabricator, or erector An examiner is a person who performs quality-control examinations Inspection by the owner does not relieve the manufacturer, fabricator, or erector of the responsibility for: Providing materials, components, and workmanship in accordance with code requirements and engineering design Performing all required examinations Preparing suitable records of examinations and tests for the inspector’s use To summarize this brief section on codes, the welding inspector must have copies of, or access to, the applicable codes, read and understand them, and apply the applicable requirements to the welding operations As shown above, the various new fabrication codes can differ dramatically on their requirements for welding inspection National Board Inspection Code (NBIC), A Manual for Boiler and Pressure Vessel Inspectors name Inspection, Rafing,Repair, and Alteration API 570, Piping lnspecfion Code: Inspection, Repair, Alteration, and Rerating of ln-Service Piping Systems Each of the above has developed Inspector Certification programs that are pertinent to the specific codes As always, certifications lend credibility to any inspection program and are encouraged Often, for petrochemical plants, annual or biannual inspections called ‘turnarounds’ or ’shutdowns’ are scheduled to permit necessary inspections, repairs, equipment modifications, or other work that cannot be done while the plant is operating These events usually require considerable preplanning to complete the required inspections and repairs in the shortest time available to minimize production losses Work is typically scheduled to continue around the clock and the inspection work is done in shifts This approach requires careful attention to the communication procedure between successive shifts to ensure completion of all inspections and repairs A variety of shift arrangements are possible for continuous work schedules: scheduling three 8-hour shifts for the 24-hour day has the advantage of permitting the oncoming shift to overlap briefly with the off-going shift for communication relay, both written and verbal Another approach used is to 14 AWS Practical Reference Guide ``,``-`-`,,`,,`,`,,` - Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale ~ ~ S T D * A W S PRGVT-ENGL 1999 0784265 0519393 475 I Pressure Vessel Inspection Code: Maintenance Inspection, Rating, Repair, and Alteration API 610 EIGKTH EDTTION,JUNE 1097 Figure 14 National Board Inspection CodeA Manual forBoiler and Pressure Vessel Inspectors (NBIC) Many governing agencies and codes require an Authorized Inspector for boilers and pressure vessels, usually referring to one certified as a National Board Inspector working to the NBIC The NBIC covers installations other than those covered by API 510 unless the jurisdiction rules otherwise ``,``-`-`,,`,,`,`,,` - have two 10-hour shifts, with a two-hour span between the shifts to permit radiographic inspection to occur with minimum personnel available This two-shift approach does present more difficulty on relaying equipment or inspection status since the verbal link does not occur, but it has been used successfully when written communication is done well Figure 15 API 51O Petroleum and petrochemical process equipment integrity must conform to 51O Anticipated problems to be found Repairs likely to be needed Spare parts required Time allotment necessary for completing all required work Inspection personnel required Inspection equipment and supplies required Typically, in preplanning, if equipment history reports and corrosion data are available, they are carefully reviewed in an attempt to realistically estimate the following: Welding personnel required Other issues (asbestos removal, vessel entry standbys, etc.) AWS Practical Reference Guide 15 Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale 078ir265 05393ïir 3 Appropriate safety equipment-gloves, hard hat, goggles, safety shoes, safety harness or wristlets This approach, if done by experienced personnel, usually minimizes or eliminates the unexpected surprises that can cause extended delays in restarting the plant A good preplanning effort is usually time and effort well spent, often resulting in considerable savings by avoiding extended production losses The inspection personnel used for shutdown work needs to have considerable background and training in safety procedures, the particular chemical or manufacturing process, equipment inspection, and repair experience Often the equipment must be entered to complete a thorough visual inspection and this requires safe entry procedures and appropriate standby personnel to ensure the safety of all personnel entering the vessels or piping Knowledge of the manufacturing process, the process chemistry, and the equipment being inspected generally lead to completion of the appropriate inspections Repair experience is also very helpful since the inspector is often the person most familiar with the equipment internals and the person who not only finds the initial equipment deterioration or damage and assists with the repair procedure, but he/she must also follow up on re-inspecting the field repairs Standby personnel on hand with radio, air horn, etc Appropriate ladders to facilitate entry (scaffolding may be required) SCBA (Self-contained Breathing Apparatus) available at vessel entry site Once all of the safety considerations have been satisfied, the inspector must check the inspection equipment to make sure the necessary tools are on hand There are several personal items each inspector should have to aid the visual inspection: Good flashlight, with fresh batteries, and the capability to be focused to a spot Small scraper, such as a stiff putty knife Sharp scribe-a tungsten-pointed one is excellent, or a stainless-steel dental pick, or both lox magnifier-lighted ones are available Pencil magnet 10-12 foot tape Entering and inspecting pressure vessels must be carefully done to comply with the required safety procedures as well as to find any existing damage Prior to entering a process vessel, the following steps must be completed as a minimum: Six-inch machinist’s scale Note pad and pen for notes, sketches Small tape recorder for dictation of conditions (optional but very helpful) A management-authorized vessel-entry form A belt pack to contain the above Vessel cleaned and decontaminated Vessel blanked out from all piping Vessel checked for explosive tendencies and flammability Vessel checked required for oxygen content-21% Lock, tag, and try of agitators or other mechanical devices Removal of ail radioactive monitoring equipment if they present a personnel hazard Mechanical ventilation of vessel if required by permit A management-authorized flame permit if welding is to be done Most of the above items are readily available, but several of the specialty items can be purchased from inspection supply firms such as Metallurgical Supply, Houston, Texas Additional visual inspection items such as borescopes, digital or 35mm cameras, video cameras, and video probes can be very useful for recording inspection results for future comparison Black-and-white camera technology is often adequate, but color cameras are usually better for documenting corrosion damage While this equipment can be purchased, rental is often the most economical approach The next item to check is the equipment’s identification; it must be confirmed by checking its ID plate Some operating functions in a manufacturing plant are such that more than one identical unit is available for a particular function Examples of this are equipment duplicates that fill the need to take 16 AWS Practical Reference Guide Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale ``,``-`-`,,`,,`,`,,` - S T D e A W S PRGVT-ENGL 9 S T D * A W S PRGVT-ENGL 3999 it in kind, or there may be spare pumps for a particular location to permit replacement of seals A spare unit having its own ID is put into place and operations continue It is imperative that each unit’s ID be confirmed before the inspection begins Many feel the vessel entry access port should be the starting point for the vessel inspection; careful examination prior to entering ensures it is not forgotten as you exit the vessel later (In one case, the entry nozzle was not inspected, and the existing corrosion damage that was overlooked caused a leak and a very expensive and unscheduled shutdown on startup.) Typically, flange faces, nozzle necks, and nozzle attachment welds are inspected for mechanical or corrosion damage as the inspector makes the initial entry Once within the vessel, it is carefully and thoroughly inspected for mechanical and corrosion damage Vessel inspections may require removal of internal manways between different levels, or baffling which may obstruct the view of portions of the vessel Often, ladders or scaffolding are required to gain access to all of the interior surfaces Inspection of surfaces usually requires accessibility within an arm’s length; long-distancevisual inspection is usually not adequate since damage may be overlooked Some inspectors take the position that if they cannot touch a surface, they cannot adequately inspect it D 07842b5 0539395 248 for equipment damage without complete insulation removal When the equipment inspection is complete, all results should be documented and discussed with the appropriate management and maintenance personnel Needed repairs are planned and discussed with the welding or mechanical supervision to ensure that all damaged areas are well understood as to their location, extent of damage, and required repairs Often, the inspector will revisit the equipment location or even reenter the vessel with the repair personnel to point out exactly what is required Once all repairs are completed, they must be re-inspected Piping presents a difficult inspection task because of several reasons: fluid velocities can create erosion or corrosion problems on the interior; there may be so much of it, it often is not readily accessible at ground level; it is often insulated, and usually is too Piping Inspection Code When damage is found, it should be noted and described in some manner to permit accurate reportage later The damaged surfaces should also be marked legibly if further action is required during the shutdown For carbon steels, a soapstone marker is quite good for marking; stainless steels and other bright alloys may require a paint marker When using paint markers, it is imperative they not contain high sulfur, chlorides, zinc, lead or other elements whose residue can cause damage to the metals during subsequent cutting or welding operations After the vessel interior is inspected, the exterior must also be examined for deterioration This can be very difficult and costly if the vessel is insulated as so many process vessels are Damaged insulation is often the first indication that insulation removal and inspection may be required If water can find its way into the insulation via damaged vapor barriers, the resulting moist, hot conditions can cause severe corrosion of the external surfaces Radiography and ultrasonic testing are often used to inspect API 570 SECOND EDITION OCTOBER IC98 Figure 16 API 570 This code applies to maintaining the piping integrity of chemical service piping AWS Practical Reference Guide 17 ``,``-`-`,,`,,`,`,,` - Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale ``,``-`-`,,`,,`,`,,` - small to permit personnel entry for internal inspection Again, as for pressure vessels, damaged piping insulation is often an indication that further external inspection is necessary after insulation removal RT and UT are very helpful in determining the condition of piping, both internally and externally When making spot inspections on piping, primary attention is often given to those areas more likely to suffer erosion/ corrosion such as locations of changes in fluid direction at elbows, or areas of high turbulence, such as branch connections or valve and pump installations Experience will often dictate the trouble spots within a piping system Piping suffering from corrosion and wall thinning may no longer be adequate for containing design pressures Sometimes it is possible to re-rate the maximum pressure permitted to a lower value, but often, piping suffering from wall thinning is replaced This same approach can be used for wall thinning of vessels A design engineer is given the current condition of the piping or vessel and through calculations determines the safe working temperatures and pressures for the damaged equipment Summary Several aspects of pressure containment equipment inspection have been reviewed Distinction was made between those national codes pertaining to the design and fabrication of new pressure equipment and those with applicability to maintaining equipment and piping integrity after the items have been placed in service There are numerous technical references that treat the subject in much greater detail, and the serious inspector is encouraged to seek these out and increase his or her knowledge and understanding of the entire inspection process I have developed the very strong feeling that inspection does not cost money; it saves money Management should look at their inspection forces not as a drain on the economics of their business, but as one of the more important divisions that protect them from poor quality often leading to bankrupting lawsuits 18 AWS Practical Reference Guide Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale Annex A-Technical I I I l and Scientific Organizations Abrasives Engineering Society (AES) P.O Box 3157 Butler, PA 16003 (724) 282-6210; fax 282-6210 American Iron and Steel Institute (AISC) 1101 17th Street, N.W Washington, DC 20036-4700 (202) 452-7100; fax 463-6573 Aluminum Association (AA) 900 19th Street, N.W Suite 300 Washington, DC 20006 (202) 682-8000; fax 682-8115 American National Standards Institute (ANSI) W 42nd Street 13th Floor New York, NY 10036-8002 (212) 642-4900; fax 398-0023 America Society for Testing Materials (ASTM) 100 Barr Harbor Drive W Conshohocken, PA 19428 (610) 832-9500; fax 832-9555 American Nuclear Society (ANS) 555 N Kensington Avenue La Grange, IL 60526 (708) 579-8200; fax 579-8283 American Association of State Highway & Transportation Officials (AASHTO) 444 N Capital Street, N.W Suite 249 Washington, DC 20001 (202) 6245800; fax 624-5806 American Bureau of Shipping (ABS) Two World Trade Center 106th Floor New York, NY 10048 (212) 839-5000; fax 839-5130 American Gas Association (AGA) 1515 Wilson Boulevard Arlington, V 22209 A (703) 841-8400; fax 841-8406 American Institute of Mining, Metallurgical and Petroleum Engineers (AIME) Three ParkAvenue New York, NY 10016-5598 (212) 419-7676; fax 371-9622 American Institute of Plant Engineers (AIPE) 8180 Corporate Park Drive Suite 305 Cincinnati, OH 45242 (513) 489-2473; fax 247-7422 American Institute of Steel Construction (AISC) One E Wacker Drive Suite 3100 Chicago, IL 60601-2001 (312) 670-2400; fax 670-6573 American Petroleum Institute (API) 1220 L Street, N.W Washington, DC 20005-8029 (202) 682-8000; fax 682-8115 Amencan Railway Engineering Association (AREA) 50 F Street, N.W Suite 7702 Washington, DC 20001-2183 (202) 639-2190; fax 639-2183 American Society for NondestructiveTesting (ASNT) 1711 Arlingate Lane Columbus, OH 43228-0518 (614) 274-6003; fax 274-6899 American Society for Quality (ASQ) 611 E Wisconsin Avenue Milwaukee, WI 53202 (414) 272-8575; fax 272-1734 American Society of Civil Engineers (ASCE) 1801 Alexander Bell Drive Reston, V 20191-4400 A (703) 295-6000; fax 295-6222 American Society of Mechanical Engineers (ASME) Three ParkAvenue New York, NY 10016-5990 (800) 843-2763; fax (973) 882-1717 American Society of Safety Engineers (ASSE) 1800 East Oakton Street Des Plaines, IL 60018-2187 (708) 692-4121; fax 296-9220 AWS Practical Reference Guide 19 ``,``-`-`,,`,,`,`,,` - Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale American Water Works Association (AWWA) 6666 W Quincy Avenue Denver, CO 80235 (303) 794-7711; fax 794-7310 American Welding Society (AWS) 550 N.W LeJeune Road Miami, FL 33126 (305) 443-9353; fax 443-7559 ASM International (ASM) 9639 Kinsman Road Materials Park, OH 44073 (440) 338-5151; fax 338-4634 International Oxygen Manufacturers’ Association (IOMA) P.O Box 16248 Cleveland, OH 44116-0248 (216) 228-2166; fax 228-5810 International Titanium Association (ITA) 1871 Folsom Street Suite 200 Boulder, CO 80302-5714 (303) 443-7515; fax 443-4406 Association of Iron and Steel Engineers (AISE) Three Gateway Center Suite 1900 Pittsburgh, PA 15222 (412) 281-6323; fax 471-4858 Material Handling Industry (MHI) 8720 Red Oak Boulevard Suite 201 Charlotte, NC 28217-3957 (704) 522-8644; fax 676-1199 Canadian Standards Association (CSA) 178 Rexdale Boulevard Rexdale, Ontario M9W 1R3 Canada (416) 747-4000; fax 747-4149 National Association of Corrosion Engineers (NACE) P.O Box 218340 Houston, TX 77218-8340 (281) 228-6200; fax 228-6300 Compressed Gas Association (CGA) 1725 Jefferson Davis Highway Suite 1004 Arlington, VA 22202-4102 (703)412-0900; fax 412-0128 Edison Welding Institute (EWI) 1250 Arthur E Adams Drive Columbus, OH 43221 (614) 486-5000; fax 688-5001 Fabricators’ and Manufacturers’ Association (FMA) 833 Featherstone Road Rockford, IL 61107-6302 (815) 399-8700; fax 399-7279 Institute of Electrical and Electronics Engineers (IEEE) Three ParkAvenue New York, NY 1006 (212) 419-7900; fax 752-4929 Institute of Industrial Engineers (IIE) 25 Technology Park Norcross, GA 30092 (770)449-0460; fax 263-8532 National Board of Boiler and Pressure Vessel Inspectors (NBBPVI) 1055 Crupper Avenue Columbus, OH 43229 (614) 888-8320; fax 888-0750 National Electrical Manufacturers’ Association (NEMA) 1300 N 17th Street Suite 1847 Rosslyn, VA 22209 (703) 841-3200; fax 841-5900 National Fire Protection Association (NFPA) P.O Box 9101 One Batterymarch Park Q u ~ ~ cMA 02269-9101 Y, (617) 770-3000; fax 770-0700 National Institute of Standards and Technology (NIST) 325 Broadway Boulder, CO 80303-3328 (303) 497-3000 20 AWS Practical Reference Guide Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale ``,``-`-`,,`,,`,`,,` - Association of American Railroads (AAR) 50 F Street, N.W Washington, DC 20001 (202) 639-2100; fax 639-2286 Laser Institute (LI) 12424 Research Parkway Suite 125 Orlando, FL 32826 (407) 380-1553; fax 380-5588 STD-AWS PRGVT-ENGL 1999 = National Society of Professional Engineers (NSPE) 1420 King Street Alexandria, V 22314 A (703) 684-2800; fax 836-4875 Robotics Industries Association (RIA) 900 Victors Way Ann Arbor, MI 48106 (734) 994-6088; 994-3338 National Welding Supply Association (NWSA) 1900 Arch Street Philadelphia, PA 19103 (215)564-3484; fax 564-2175 222 Palisades Creek Drive Richardson, TX 75083 Naval Inventory Point Center 700 Robins Avenue Philadelphia, PA 19111 (215) 697-2247; fax 697-5914 Order and Inquiry Desk U.S Government Printing Office Washington, DC 20402 (202)512-1800; fax 512-2250 Resistance Welder Manufacturers’ Association (RWMA) 1900 Arch Street Philadelphia, PA 19103 (215) 564-3484; fax 963-9785 Society of Petroleum Engineers (SPEI (972) 952-9393; fax 952-9435 Society of Women Engineers (SWE) 120 Wall Street New York, NY 10005-3902 (212) 509-9577; fax 509-0224 Steel Tank Institute (STI) 570 Oakwood Road Lake Zurich, IL 60047 (847)438-8265; 438-9766 Uniform Boiler and Pressure Vessel Laws Society (UBPVLS) 308 N Evergreen Road Suite 240 Louisville, KY 40243-1010 (502) 244-6029; fax 244-6030 ``,``-`-`,,`,,`,`,,` - I W t b 0519399 993 AWS Practical Reference Guide 21 Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale = 07842b5 05L9400 435 m S T D O A W S PRGVT-ENGL 1999 Annex B-1998 ASME Boiler and Pressure Vessel Code Sections Division Code for Concrete Reactor Vessels and Containments Division Containment Systems and Transport Packaging for Spent Nuclear Fuel and High-Level Radioactive Waste IV-HEATING BOILERS V-NONDESTRUCTIVE EXAMINATION VI-RECOMMENDED RULES FOR THE CARE AND OPERATION OF HEATING BOILERS VII-RECOMMENDED GUIDELINES FOR THE CARE OF POWER BOILERS VIII-PRESSURE VESSELS Division Division 2-Alternative Rules Division &Alternative Rules for Construction of High-pressure Vessels IX-WELDING AND BRAZING QUALIFICATIONS X-FIBER-REINFORCED PLASTIC PRESSURE VESSELS XI-RULES FOR INSERVICE INSPECTION OF NUCLEAR POWER PLANT COMPONENTS Code Cases: Boilers and Pressure Vessels Code Cases: Nuclear Components ``,``-`-`,,`,,`,`,,` - I-POWER BOILERS II-MATERIALS Part A-Ferrous Material Specifications Part &Nonferrous Material Specifications Part C-Specifications for Welding Rods, Electrodes and Filler Metals Part D-Properties III-RULES IN CONSTRUCTION OF NUCLEAR POWER PLANT COMPONENTS Subsection NCA-General Requirements for Division 1and Division Division Subsection NB Class Components Subsection NC Class Components Subsection ND Class Components Subsection NE Class MC Components Subsection NF Supports Subsection NG Core Support Structures Subsection NH Class 1Components in Elevated Temperature Service Appendices 22 AWS Practical Reference Guide Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale Annex C-Discontinuities (From AWS B1.10,Table 1) Table Common types of discontinuities Remarks Location' ripa of Discontinuity ~ Porosity (a) Uniformly scattered (b) Cluster (c) Linear (d) Piping Inclusions (a) Slag (b) Tungsten WM Incomplete fusion WM, BMNVM Incomplete joint penetration Porosity is also commonly found in the heat-affected zone if base metal is a casting NM BM Also between passes Weld root ~ ~~ Adjacent to weld toe or weld root in base metal Undercut BMMIM Underfill WM Weld face or root surface Overlap BMMIM Weld toe or root surface Laminations BM Base metal, generally near midthickness of section Delamination BM Base metal, generally near midthickness of Section ~~ Base metal surface almost always aligned with rolling direction 10 Seam and laps 11 Lamellar tears BM Base metal, near HAZ 12 Cracks (includes hot cracks and cold cracks) (a) Longitudinal (b) Transverse (c) Crater (d) Throat (e) Toe (4 Root (9) Underbead and heat-affectedzone WM, HAZ WM, HAZ, BM WM WM BMMIM WM BMNVM Weld metal or base metal adjacent to weld interface Weld metal (may propagate into HAZ and base metal) Weld metal at point where arc is terminated Parallel to weld axis 13 Insufficientthroat WM Root surface Weld face ~ ~~ 14 Convexity or weld reinforcement WM Weld face 15 Insufficientleg WM Fillet weld *WM-Weld metal BM-Base metal HAZ-Heat-affected zone BMNVM-Weld interface AWS Practical Reference Guide 23 ``,``-`-`,,`,,`,`,,` - Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale S T D W A W S PRGVT-ENGL 1979 M 07842b5 0519402 208 M Annex C-Disconti nuities (Continued) (From AWS 81.10, Table 2) Table Discontinuities commonly encountered with welding processes I Welding Process I Type of Dlscontinuity Porosity I Slag I Incomplete Fusion Incomplete Penetration I Undercut Overlap Cracks Arc SW-Stud welding PAW-Plasma arc welding SAW-Submerged arc welding GTAW-Gas tungsten arc welding GMAW-Gas metal arc welding FCAW-Flux cored arc welding SMAW-Shielded metal arc welding CAW-Carbon arc welding Resistance RSW-Resistance spot welding RSEW-Resistance seam welding PW-Projection welding FW-Flash welding UW-Upset welding OAW-Oxyacetylene welding OHW-Oxyhydrogen welding PGW-Pressure gas welding X X X X X 1:l X X X CW-Cold welding DFW-Diffusion welding EXW-Explosion welding FOW-Forge welding FRW-Friction welding USW-Ultrasonic welding EBW-Electron beam welding ESW-Electroslag welding IW-Induction welding LBW-Laser beam welding PEW-Percussion welding TW-Thermit welding X X X X X X X X X X X X X X X X X X X X X X 24 AWS Practical Reference Guide ``,``-`-`,,`,,`,`,,` - Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS X X X X X Not for Resale X X X X X X X X X X X X X X X Annex C-Discontinuities (Continued) (From AWS-The Everyday Pocket Handbook for Visual Inspection and Weld L)iscontinuifies-Causes and Remedies) Cracks A crack is defined as “A fracture type discontinuity characterized by a sharp tip and a high ratio of length and width to opening displacement.” Cracks are usually considered the most severe discontinuity because of their tendency to propagate under stress Cracks are usually further described by their location geometry, time of occurrence, or common usage terms; see figure below for AWS crack terminology LEGEND: CRATER CRACK FACECRACK HEAT-AFFECTED ZONE CRACK LAMELLARTEAR LONGITUDINAL CRACK ROOTCRACK 10 11 12 ROOT SURFACE CRACK THROAT CRACK TOE CRACK TRANSVERSE CRACK UNDERBEADCRACK WELD INTERFACE CRACK 13 WELD METAL CRACK Inclusions Inclusions are defined as ”Entrapped foreign solid material, such as slag, flux, tungsten, or oxide The inclusions may be found as single particles, aligned particles, or clustered particles Slag inclusions are frequently found on the weld surfaces, or along the toes of the weld due to improper cleaning techniques Tungsten inclusions are usually subsurface Examples of inclusions are shown below Inclusions on the surface can be detected by VT;subsurface inclusions require UT or RT .I’ Slag Inclusions (darkened areas) Incomplete Fusion Incomplete fusion is defined as ”A weld discontinuity in which fusion did not occur between weld metal and fusion faces or adjoining weld beads.” Incomplete Fusion (IF) can occur on both groove welds and fillet welds The term specificallyapplies to fillet welds where the weld does not extend to the joint root See the figures below AWS Practical Reference Guide 25 ``,``-`-`,,`,,`,`,,` - Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale INCOMPLETE FUSION (6) INCOMPLETE FUSION Incomplete Joint Penetration Incomplete joint penetration is defined as "A joint root condition in a groove weld in which weld metal does not extend through the joint thickness."Note that it applies to groove welds only, notfillet welds Examples of incomplete joint penetration (IJP) are shown in the following figures INCOMPLETE JOINT PENETRATION INCOMPLETE JO¡NT PENETRATION ``,``-`-`,,`,,`,`,,` - Overlap Overlap is defined as "The protrusion of weld metal beyond the weld toe or weld root." Examples are shown below for fillet and groove welds OVERLAP 26 AWS Practical Reference Guide Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale Porosity Porosity is defined as “Cavity-type discontinuities formed by gas entrapment during solidification or in a thermal spray deposit.” The porosity may be surface or subsurface, a single cavity, aligned, or clustered, and is represented by the followmg fig& CLUSTERED SUBSURFACE POROSITY f===¡=l r SCATERED SUBSURFACE POROSITY SCATTERED SURFACE POROSITY Undercut r-9 UNDERCUT UNDERCUT i L?lH AWS Practical Reference Guide 27 Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale ``,``-`-`,,`,,`,`,,` - Undercut is defined as “A groove melted into the base metal adjacent to the weld toe or weld face and left unfilled by weld metal.” Examples are shown in the following figures Annex D-Selected References AWS-The Everyday Pocket Handbookfor Visual Inspection and Weld Discontinuities AWS B1.lO-Guide for the Nondestructive Inspection of Welds AWS B1.11-Guide for the Visual Inspection of Welds AWS A3.û-Standard Welding Terms and Definitions AWC A2.4-Standard Symbols for Welding, Brazing, and Nondestructive Examination AWS B2.1-Specification for Welding Procedure and Performance Qualification AWS-The Practical Reference Guidefor Corrosion of Welds-Causes and Cures NDE Handbook-Non-destructive examination methods for condition monitoring, edited by Knud G Boving, available through AWS NACE-Process Texas Industries Corrosion, available from National Association of Corrosion Engineers, Houston, ``,``-`-`,,`,,`,`,,` - NACE-NACE Corrosion Engineer’s Reference Book, Second Edition, edited by R S Treseder, available from National Association of Corrosion Engineers, Houston, Texas 28 AWS Practical Reference Guide Copyright American Welding Society Provided by IHS under license with AWS No reproduction or networking permitted without license from IHS Not for Resale ... Handbookfor Visual Inspection and Weld Discontinuities AWS B1.lO -Guide for the Nondestructive Inspection of Welds AWS B1.11 -Guide for the Visual Inspection of Welds AWS A3.û-Standard Welding Terms and. .. visual inspections of the fitup, the root pass, and the final weld, and were signed off after each of the three visual inspections This "visual inspection only" approach was used in lieu of the. .. PRGVT-ENGL 1999 0784265 051937b 396 E THE PRACTICAL REFERENCE GUIDE for WELDING INSPECTION MANAGEMENTVisual Inspection of Pressure Vessels and Pressure Piping Ted V Weber Principal Consultant