|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 involved 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.
Variables used in a welding procedure test are divided into 3 categories :-
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.
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 mechanical 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 eg 5A,5B
etc., Treat each sub group like a separate
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 pipework to B31, a P number covers an S number but not the converse
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 for fillet welds as per QW462.4a or QW462.4d qualify all fillet weld sizes on all base material thicknesses and all diameters in one test.
Testing 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:-
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 variables 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.
|Page last updated 1 September 2001