ASME 9 - Introduction These articles are intended as a very general guide to ASME 9. They are a collection of my own personal notes which were written to aid my understanding of the code. There are certain exceptions in the code that are not covered in these articles, therefore you are urged to study the code carefully before using its rules to carry out any welding qualifications. qualifications.
Contents: y y y y y y y y y
Brief Introduction Download ASME suggested forms Procedure Qualification Record (PQR) Welding Performance Qualification (WPQ) ASME definitions for welding processes, consumables and welding positions ASME Approval Range Calculator ASME P Material Numbers Graphic Representation of Welding Positions Multi Process Welding Procedures QW200.4 and QW 451.1
Brief Introduction Welding qualifications to ASME 9 are for use with the ASME boiler and pressure vessel code or the ASME pipe work codes. For use with any other code or standard agreement between all contracting parties should be obtained. The ASME boiler and pressure vessel code embraces its own QA system which revolves around satisfying the rules of the code. This demonstrates that an accredited accredited fabricator has some degree of competence permitting them to perform a large amount of their own inspection without the involvement of an Independent Inspection Body, which would be required by other standards for similar inspections. This is why welding qualifications were were usually carried out under the ASME code because it does not require independent inspection. A f abricator can qualify its own procedures and welders using the ASME code rules. Howe However ver this may not be acceptable to the European Pressure Equipment Directive which requires all welding qualifications in inspection categories categories two and above to be approved by a Notified Body. ± Article II: Welding Procedure Qualifications, QW ± 200.2 However there is nothing stopping anybody using any of the rules of the ASME code without being ASME approved, but to prove your competence in welding an Independent Inspection Body is recommended to approve your welding tests. The advantage of ASME 9 is that it¶s very workable and v ery comprehensive, if you have a question you will almost certainly find an answer somewhere in the code, which is more than can be said for its European equivalent EN ISO 15614-1 (formerly EN288-3). The ASME code may at first glance appear complex and v ery legalistic but once you understand the
basic rules they are very easy to apply in practice. Its main advantage is that it requires very few welding procedures unlike EN ISO 15614-1 which requires a ridiculous number if it is applied correctly. The main advantages of ASME welding procedures are: All joint types approve each other. i.e. A double sided weld approv es a single sided weld and vice versa. No limits on diameter approval for pipe. A plate procedures can be used to weld any diameter of pipe Materials and welding consumables are listed in groups, unfortunately only American grades are included! Any butt weld will qualify all fillet weld sizes on any parent metal thickness. A welding procedure qualified in one position approves all positions unless im pact tests are required then only a vertical up approves all positions. The code covers wide range of welding processes and appli cations such as hard facing, stud welding, brazing etc. If you have difficulty in appreciating the above advantages you need to understand the basic philosophy behind welding procedure tests described in the µBasic Guide¶. The main advantages of ASME welder approval tests are:There is no minimum parent metal thickness, only maximum, and they are applied to the deposited thickness of the weld not the parent metal thickness. There is no upper limit on diameter approval, only a lower limit. Any butt weld approval will qualify all fillet weld sizes on any parent metal thickness. {Unfortunately unlike EN287 a butt weld carried out in the flat position will not qualify a fillet weld in the conventional horizontal position, to qualify this, your butt weld approval must include the horizontal position}. The main problem with the ASME code is that it treats all welding processes separately and imposes separate restrictions for each on both procedures and approvals. It is therefore prudent to check what the code says about the welding process you intend to use before you carry out any welding tests. The ASME code covers a very wide range of welding processes and applications such as hard facing, stud welding, brazing etc. Application standards such as the B31 pipe work code may impose additional requirements and limitations in some cases. The code is divided into 4 parts as follows: QW100
General introduction to testing requirements etc.
QW200
Procedure Qualification details.
QW300
Performance Qualifications (Welder Approvals) details.
QW400
Welding Data. This is the biggest section of the code and covers data for both procedure and performance qualifications. It includes :y y y
y
Material and consumable data Test requirements. Approval ranges for thickness, diameter, joint configuration and welding positions Definitions used in the code.
Procedure Qualification Record (PQR)
PQR's are not required if Standard Welding Procedures are used, see below for details. This document contains details of the welding test, it must include details of all the parameters listed as variables in tables QW250 to QW265 for each process involv ed and all the destructive test results. The relevant variables for each type of welding process are clearly defined in tables QW250 to QW265. The left hand column of each table defines the section and paragraph where each variable and its application to the table is explained in the code. Welding Variables Variables used in a welding procedure test are divided into 3 categories :y
y
y
Essential Variables Are variables that have a significant affect on the mechanical properties of a joint. They must not be changed except within the limits specified by this code. e.g. Material thickness range, Material Group etc. Non-Essential Variables
Are variables that have no significant affect on mechanical properties. They can be changed without re qualification of the PQR. Supplementary Variables Are variables that have an affect on the impact properties of a joi nt. They are classed as Non-Essential if impact testing is not required
All variables listed as essential, non-essential or supplementary should be addressed on both the WPS and the PQR. If any of the v ariables do not apply to the particular application then they should be specified as not applicable. Joint Configuration Either plate or pipe can be used for the test piece (plate approves pipe and vice v ersa ref. QW211), any welding position approves all positions providing no impact tests are required ref. tables QW250 to QW265 and any joint geometry approves all geometry's, e.g. single V, double V, U prep, backed or unbacked. A butt or groove weld approves branch and fillet welds but not the converse, ref. QW202. Non pressure retaining fillet welds in pipe or plate can be tested but they must be double sided if plate and at least the
dimensions illustrated in QW462.4a, ref. QW202.2c. Pressure retaining branch welds must be qualified by groove (butt) welds. Material Grouping Materials are assigned P numbers in QW420; a test in one P number approves all materials listed under that P number, except where impact tests are required then approval is restricted to materials listed in the group number within the P number. Other P number groupings are permissible ref. QW424.1 for details. Ref QW 424.1 for further details. It is normally permissible if the material is not listed in QW422 to assign it to a P number which lists materials with the same metallurgical and m echanical properties although this is not in strict conformance with the code. Typically BS1501 151 430A low carbon steel could be regarded as P1 and stainless steels such as 316, 304 as P8. Note P5, 9 & 10 are divided into sub groups e.g. 5A, 5B etc., Treat each sub group li ke a separate P Number Dissimilar materials are acceptable providing they are compatible. For example P1 to P8, but this does not cover P1 to P1 or P8 to P8. Note S numbers are for pipe work to B31, a P number covers an S number but not the converse Consumables The ASME code uses its own specifications for consumables SFA which is almost identical to the AWS specification. NOTE
A change in consumable is only permissible providing it has the same F number and A number (if applicable) as the P.Q.R.
Thickness Limits
Thickness limits Groove welds. See QW451 f or precise details. y y
When Impact tests are required the minimum thickness approved is restricted. See QW403.6 More than one PQR may be required to qualify dissimilar thickness
The thickness little 't' of deposited weld metal for each process involved is approved from 0 to 2x the t except:y
y
MIG/MAG (GMAW/FCAW) dip transfer weld of deposited thickness less than ½" approves maximum thickness of 1.1 x t only Ref: QW255 (QW403.10) If any Pass in a single or multi-pass weld > ½" then the thickness approval equals 1.1xT
Dissimilar Thickness QW202.4:- The thicker and thinner part must be qualified, Except P8 and P4X the thinner part can be qualified if no Impacts and test coupon > 6mm thick. Thickness limits for fillet welds as per QW 462.4a or QW462.4d qualify all fillet weld sizes on all base material thicknesses and all diameters in one test. T esting
Requirements (Ref QW 463 for location of specimens)
Unlike EN288 there is no requirement for any non-destructive testing such as radiography or MPI/DPI, although I would recommend radiography for butt welds. The testing requirement for groove welds are as follows:y
y
Two Transverse tensile tests (QW150). Two Root bends and Two face bends unless the plate thickness exceeds 3/8" then 4 side bends are required. All bend tests should be done to QW160 using the correct former ref. QW466 to an angle of 180 degrees. Longitudinal (all weld) bend tests are not recommended unless the base/weld materials differ markedly in bending properties. See QW 466 for exceptions and precise details.
The testing requirement for fillet welds on plate is 5 macro sections only, for Pipe fillet welds 4 macro sections. No fracture test required.
Welding Procedure Specifications (WPS) This document details the practical application of the Procedure Qualification Record (PQR). It should contain enough information to give direction to the welder and should address all v ariables associated with the welding process defined in QW250 including non essential and supplementary. A WPS can combine welding processes from other PQR's but all the relevant variables must be addressed including parent metal thickness. There is an exception to this rule for root runs from PQR's that are greater than 1.5 inches thick (38.1mm), see code for details.
Standard Welding Procedures Specifications (SWP's) Standard welding procedures listed in annex E of ASME IX can be purchased from the 'American Welding Society' and used without qualifying a PQR. Section V of ASME IX gives details of essential variables and restrictions. A successful welder performance qualification must be carried out to demonstrate the SWP's before a manufacturer can use it.
Welder Performance Qualification (WPQ)
Materials The purpose of this test is to determine the welders ability to deposit a sound weld therefore the base material is not considered as critical as it is in the PQR. Hence a performance test on any m aterial in P groups 1 to 11 approves all those groups and sub groups, also P34 and P4X (P40-P49). Providing a compatible consumable exists with the same F number used in the qualification test. (QW423.1) Note a single sided weld is classed as a weld without backing and a double sided weld or weld with sealing run is classed as a weld with backing Consumables The F number cannot be changed without re qualification of the welder except that for performance qualification only using SMAW (MMA) F numbers up to and including 4 approve all lesser F numbers for double sided or welds with backing only. One Consumable from F41 To F45 approves any of these consumables, except SAW. Ref.QW404.11. Note 'A' numbers do not apply to welder approval tests. Variables For each welding process there is a list of essential variables in QW352 to QW357 and QW360 for welding operators, these are not necessarily the same as the ones f or the PQR. Essential variables cannot be changed. Explanations of all these variables is given in section IV of the code. Diameter and Thickness Ranges Diameter limits for all circular welds including groove welds, branch welds and fillet welds is giv en in QW452.3. there are no upper limits on diameters approved and pipe covers plate Note for branch welds the diameter considered for the above limits is the one containing the weld preparation. Thickness limits, groove welds. The thickness limit only applies to the deposited weld metal thickness not the plate thickness and any groove weld approves all fillet weld sizes. For t greater than 12.5mm there is no restriction on the size that can be welded (Providing the test weld deposit contains at least 3 layers of weld).
Thickness limits, fillet welds. A test on plate greater than 3/16" approves all base metal thicknesses and fillet weld sizes ref. QW452.5. (Note the above diameter limits apply unless the fillet weld is qualified by a groove weld) Joint Configuration Joint geometry, a double V (or U) is considered the sam e as a joint with backing and does not qualify a single V (or U) without backing, but a single full penetration joint without backing qualifies all joint configurations. Approval Range Extent of approval is v ery well explained in QW461.9. Take particular note of welding positions which are also explained in QW461, for example to qualify a fillet weld in the normal horizontal-vertical position with a groove weld, the groove weld must be qualified in at least the 2G position. The welding positions defined in QW461.1.& QW461.2 should be referred to in the WPS. The position
designations: 1G ,2G ,3G ,4G ,5G ,6G (Groove Welds) and 1F ,2F ,3F ,4F (Fillet Welds) are test positions Period of Validity/Renewal of Qualifications (QW 322.2) Providing the welder uses the process for which he is qualified and there is no reason to question his ability then his qualification lasts indefinitely. If the welder does not use the welding process f or which he is qualified for a period of 6 months or more then he must perform a new test in pipe or plate, any parent material, thickness and position, if successful all the welder approvals for that welding process are renewed in one t est. T esting
Requirements Test requirements for groove welds QW452 consists of either:y
One face bend and one root bend except for welding positions 5G & 6G which require 4 bends (Ref QW452.1 Note 4). If the plate exceeds 3/8" side bends may be used. See QW 466 for precise details and exceptions.
Note:-
y
Bend Tests can in most cases be replaced by Radiography {See Below}.
Radiography is optional and must be supplemented by bend tests when using GMAW (MIG/MAG) with dip transfer (Short Circuiting Arc) or when welding some special materials. Ref. QW304.
Note:-
Ultrasonic Examination in lieu of Radiography is not permitted Test requirements for fillet welds in pl ate ref. QW452.5:y
One macro section (QW 184) and One fracture test (QW 182).
The location where each specimen has to be taken is defined in QW463 Radiography Ref QW 191 y y
A length of at least 6" m ust be examined for plate or the entire circumference for pipe. If the pipe circumference is less than 6" then more samples must be welded up to a maximum of 4. Ref QW 302.2.
Visual Examination Ref QW 302.2 & QW 190 Performance test coupons must show complete joint penetration with full fusion of the weld metal and base metal. The welder performance test must follow a properly qualified W.P.S. Once qualified the welder must always work within the extent of approval of any properly qualified W.P.S. and his W.P.Q. The welder who qualifies the P.Q.R. is automatically approved within the limits specified in QW304, QW305 and QW303. Ref QW301.2. Specialist Processes Such as corrosion resistant overlay or hard facing are covered in QW 453. Procedure variables are defined with all procedure variables in QW252 and in QW380 for welder
approval. Min base thickness approved = size welded or 1", QW 453 Min Deposit Size Approved:- Point Where Chemical analysis taken No upper limit QW402.16 (462.5a) Welding Positions QW405.4 Performance Qualification approves all deposit thickness¶ No min.QW381
ASME Definitions, Consumables, Welding Positions ASME P Material Numbers Explained
ASME has adopted their own designation for welding processes, which are very different from the ISO definitions adopted by EN24063.
Designation OFW SMAW SAW GMAW FCAW GTAW PAW
Description Oxyfuel Gas Welding Shielded Metal Arc Welding (MMA) Submerged Arc Welding Gas Metal Arc Welding (MIG/MAG) Flux Cored Wire Gas Tungsten Arc Welding (TIG) Plasma Arc Welding
Straight polarity = Electrode - ve Reverse polarity = Electrode + ve ASME F Numbers F NUMBER
GENERAL DESCRIPTION
1 2 3 4 5 6 2X 3X 4X 5X 6X 7X
Heavy rutile coated iron powder electrodes :- A5.1 : E7024 Most Rutile consumables such as :- A5.1 : E6013 Cellulosic electrodes such as :- A5.1 : E6011 Basic coated electrodes such as : A5.1 : E7016 and E7018 High alloy austenitic stainless steel and duplex :- A5.4 : E316L-16 Any steel solid or cored wire (with flux or metal) Aluminium and its alloys Copper and its alloys Nickel alloys Titanium Zirconium Hard Facing Overlay
Note:- X represents any number 0 to 9
ASME A Numbers These refer to the chemical analysis of the deposited weld and not the parent material. They only apply to welding procedures in steel materials.
A1
Plain unalloyed carbon manganese steels.
A2 to A4 Low alloy steels containing Moly and Chrome Moly A8
Austenitic stainless steels such as type 316.
ASME Welding Positions Graphic Representation Note the welding progression, (vertically upwards or downwards), must always be stated and it i s an essential variable for both procedures and performance qualifications. Welding Positions For Groove welds:Welding Position Flat Horizontal Vertical Upwards Progression Vertical Downwards Progression Overhead Pipe Fixed Horizontal Pipe Fixed @ 45 degrees Upwards Pipe Fixed @ 45 degrees Downwards
T est
Position 1G 2G 3G 3G 4G 5G 6G 6G
ISO and EN PA PC PF PG PE PF HL045 JL045
Welding Positions For Fillet welds:Welding Position Flat (Weld flat joint at 45 degrees) Horizontal Horizontal Rotated Vertical Upwards Progression Vertical Downwards Progression Overhead Pipe Fixed Horizontal
T est
Position
1F 2F 2FR 3F 3F 4F 5F
Welding Positions QW431.1 and QW461.2 Basically there are three inclinations involved. y y
Flat, which includes from 0 to 15 degrees inclination 15 - 80 degrees inclination
ISO and EN PA PB PB PF PG PD PF
y
Vertical, 80 - 90 degrees
For each of these inclinations the weld can be rotated from the flat position to Horizontal to
overhead.
Multi Process Welding Procedures QW200.4 and QW451.1
Base Metal approval range for the above welded joint is 4.76mm To 52mm Ref QW451.1
If the joint is made of more than one welding process then the maximum deposited thickness each process in the above example is (2 x Deposited Weld Metal t) :- GTAW 12mm and SMAW 52mm (This is because t = T f or this process as t > 19.1mm QW451.1)
If the SMAW deposit in the above qualification was less than 19.1mm, assume 18mm and GTAW 8mm then to weld a joint 52mm thick with 8mm GTAW and 44mm SMAW is not permitted as maximum SMAW deposit would be 36mm
You can delete the SMAW and qualify an all GTAW weld 4.76mm To 12mm thick or delete the GTAW and weld SMAW 4.76mm to 52mm thick, providing all the essential, non essential and supplementary variables are applied to the WPS. (Note the procedure allows the SMAW to be used as a root run but not the welder qualification.)
When tested the deposited weld metal of each process must be included in the tension and bend test specimens and impacts where applicable. Note it is acceptable for the impact test for the GTAW to contain some SMAW in the test specimen.
PICK and MIX QW200.4 b [Note restrictions in QW4 51.1 notes (1)] This applies to test coupons 13mm and thicker and welding processes SMAW, SAW, GTAW, GMAW. A WPS consisting of several processes can be created from different PQR¶s, but the maximum thickness of base metal covered by this WPS can¶t exceed 2 x the thickness of the thinnest test coupon used for each PQR and each process can¶t exceed 2 x its deposited thickness. This applies even if all the processes used for that coupon are not required in this WPS. However the base metal thickness of the PQR used for the root does not hav e to be considered if the WPS is single sided QW200.4 b
Note test coupons 38mm and above approve deposited weld metal and also base metal thickness up to 200mm max QW451.1. (QW403.7 Processe GTAW,SMAW,GMAW,SAW) EXAMPLE
Can the proposed PQR be made from the above example + PQR 2 + PQR 3.
Consider individual deposited thickness 2 x t GTAW 12mm > 6mm. SMAW 60mm > 39mm. GMAW 66mm > 20mm All OK
Consider Plate thickness 2 x T SMAW 60mm <65mm Fail. GMAW 66mm > 65mm OK. GTAW not considered. SMAW procedure can¶t be used for proposed PQR
WELDER PERF ORMANCE QUALIFICATIONS If you want to weld a 30mm plate and your welder qualifications only go up to 15mm use two welders. You can¶t use one welder with two different qualifications for the same process
Welding Qualifications Welding Procedures, Welder Approvals and Welding Procedure Specifications explained.
European Standards An introduction to European Welding Standards. (427Kb pdf File)
Basic Guide A basic introduction to Welding qualifications and why they are required
Welding Procedure Specifications(WPS) Welding Procedure Specifications to EN ISO 15609-1 (formerly EN288 Part 2). Why are they required and what should they include.
ASME Section IX Guidance on the qualification of welding procedures and the performance testing of welders to section 9 of the ASME boiler and pressure vessel code. Approval Range Calculator.
European & ISO Welding Standards These new standards are renumbered and updated versions of the old EN288 series. Information is also provided about the older standards. NEW Approval Range Calculator.
Automatic/Machine Welding Guidance on the qualification of welding operators to EN and ASME Rules
Independant Inspection Authority Royal & SunAlliance is probably one of the most helpful Inspection agencies around.
Return To Main Menu Page
Please Note, whilst I am prepared to answer your questions, I can't supply copies or extracts of standards because they are all subject to copyright law. However copies of most standards can be purchased online from the various standards authorities, see LINKS for their web site addresses. Page last updated 23 October 2009
