In the QW-200.1 paragraphs you are given the definition of a Welding Procedure Specification (WPS); what its contents must consist of, as well as what changes may be made with out re-qualifying the WPS. Also, here you are directed that the format may be of any form desired as long as every essential, nonessential and supplementary essential variable (when required) is included or referenced as outlined in QW-250 through QW-265. That statement permits the use of any computer generated WPS or PQR forms along with any other method the Code user may desire to use. Remember however all of the variables listed for a given process must be addressed correctly.
In the paragraphs of QW-200.2 the same type of information for the Procedure Qualification Record (PQR) is listed as was given for a WPS in the previous paragraph, starting with the definition. As in the WPS, you are given the required contents for a PQR. We are told that changes in a PQR are not permitted except for editorial changes such as the recording of a P-Number incorrectly when filling out the original PQR. Addendum is permitted if it meets the definitions as given in this paragraph. Examples of permitted addendum are given to clarify its meaning. Finally, we are instructed that it is possible to have multiple WPS s with one PQR (done by adjusting non-essential variables on the WPS to suit production) and also to have multiple PQRs with one WPS (done by supporting different essential variables by using multiple PQRs). According to the above paragraphs WPSs must contain all variables both essential and non- essential. PQRs are required to address only essential variables. Placing only essential variables on a PQR is not usually done in actual practice, but that is possible in the simplest of welding procedures.
QW-200.3 gives the purpose and an explanation of the use of P-Numbers. It is stated here that a P- Number is assigned to base metals dependent on characteristics such as composition, weldabilty, and mechanical properties where it can logically be done. Group Numbers are introduced here, stating that Group Numbers are assigned among P-Numbers to classify the metals for procedure qualification where notch toughness requirements (impact tests such as Charpy V-notch) are specified. You are also cautioned here that these assignments do not imply that base metals within a P-Number may be indiscriminately substituted.
The combination of welding procedures is permitted as given in paragraph QW-200.4. That is to say, more than one WPS can be used in a production joint, and they may include one or a combination of processes. QW-451 is referenced to make sure the reader is aware that limitations are placed on the base metal thickness and the deposited filler metal thickness of each procedure.
The types of tests required to qualify a procedure are given in paragraphs QW-202.1 through QW-202.5. Referenced therein are mechanical tests, groove and fillet welds, weld repair, dissimilar base metal thickness and stud welding. In each of the paragraphs, other QW paragraphs are referenced for details and exceptions that might exist.
QW-203 states that unless required otherwise by welding variables of QW-250, a qualification in any position qualifies the procedure for all positions. So, most PQR s can be performed on plate since the goal is to prove that the metal or metals can be successfully joined as opposed to proving the skills of a welder or welding operator.
Beginning with QW-250, welding variables are specified with an explanation of each type. Please notice the definitions of essential and nonessential variables given in QW-251.2 and QW-251.3 Welding Variables Procedure Specifications (WPS) start at QW-252 and end at QW-265. These paragraphs are in tabular form and cover the different welding processes recognized in Section IX. Within these tables for each process are lists of variables, and whether or not they are essential, nonessential or supplementary essential. These paragraphs in tabular form are labeled as „Brief of Variables‟ and reference where in the other code paragraphs of QW-400 the specific requirements and definitions can be found.
145 Article III. Welding Performance Qualifications
Overview
This article lists the welding processes separately, with the essential variables which apply to welder and welding operator performance qualifications.
In QW-300.2, the responsibility for the qualification of welders and welding operators is placed on the manufacturer and/or contractor. One important fact given is that if two companies of different names are actually part of one organization, then one company may control the welder and welding operator qualifications. That is so long as this condition is included in the quality control system of the companies and all other requirements of Section IX are met.
Starting with QW-301, tests required for welders and operators are addressed. This includes the intent of such tests, the extent of testing, identification of individual welders along with the records required for such tests.
QW-302 calls out the type of tests. They are mechanical or radiographic, and in QW-302.3, the location and removal of pipe test coupons for mechanical tests are described.
Next in this series is QW-303 where limits of qualified positions and diameters are located. You are immediately directed to the paragraphs of section QW-461, which has the graphics defining positions. QW-303.1 through QW-303.4 gives details of weld positions and the limits of qualifications for each. Welder qualifications to weld to various WPS s and limitations on qualification by radiography are to be found in QW-304. Specifics of examination for welders begin in QW-304.1. It says that welds made in test coupons may be radiographed or have bend tests performed. Alternatively, a six-inch length of the first production weld made by the welder being examined may be qualified by radiography.
In QW-304.2, failure to meet radiographic standards is discussed. If a production welder's test is flunked, the entire production weld made by the welder being tested must be radiographed and repaired by a welder who is qualified.
QW-305 through QW-305.2 is a description of how welding operators are examined and qualified. It's essentially the same as QW-304, with the length of the production radiograph being 3 feet instead of 6 inches.
In QW-305 the combining of welding processes requires that the welder be qualified either for each individual process or by the actual combining of the processes in one test coupon. Two or more welders can be qualified by a single test coupon each using the same or different processes. Each welder will be limited for thickness of deposited weld metal as given in QW-452. Failure of any portion of a combination test constitutes failure of the entire combination. All this is to be found in QW-306.
QW-310 to QW-310.3 are concerned with test coupons and welding groove welds with or with out backing.
In QW-320 retest and renewal of qualifications are divided into two categories. Immediate retest by mechanical or radiographic means, and retest after further practice
QW-321.1 outlines the mechanical tests and basically says the welder will make two consecutive test coupons for every position he failed, all of which must pass the test requirements. Retest by radiography is laid out in QW-321.2. How to handle situations dealing with further training is found in QW-321.3. Renewal of a welder's qualification for a process is mandatory when he has not used the process for the time limits as given in QW-322.1 (a) and (b).
The QW-350 paragraphs have all of the variables for welders and here you will find what changes to his essential variables will require a welder to re-qualify. These tabular paragraphs are similar to those of the Article II for welding processes using a „Brief of Variable‟ and a referenced paragraph that follows.
146 API 510 Module
SECTION IX PART QW