WPS/PQR
WPS/PQR
(OP)
We are Going to be making some strength welds on a tube to tube sheet joint we have a calculated min weld size of .053" and max weld size of .168". We submitted a wps and PQR to client welding engineer and it was returned as rejected. The client stated that the PQR has a specified min weld size of .085" and max of .168" and the PQR should have the same min weld size as the engineer calculated for the specific tube to tube sheet being welded. I am kinda of confused, my thinking is that the if calculated min weld size is .053 max.168" and the PQR specifies .083 as min it would be accepted because we are above the min cal of .053. I could see if the situation was reversed with min cal at .083 and PQR min of .053 being rejected. Can someone help me understand the tube to tube sheet with strength weld calculated min/max weld size and the WPS/PQR required.





RE: WPS/PQR
The PQR does not typically specify the range of qualification, only the thickness of the materials actually used to qualify the WPS.
Best regards - Al
RE: WPS/PQR
RE: WPS/PQR
I usually develop a preliminary WPS (PWPS)that defines how the WPS will be qualified. It is simply an unqualified WPS that provides the welder with all the information needed to secure the proper material of he correct thickness, how to prepare the joint to be welded, what welding process and filler metal will be used, what filler metal will be used, what welding parameters will be used, etc. The PWPS is developed after reviewing the production requirements to ensure the proper material thickness is used to cover production requirements, the filler metal is appropriate, etc.
Following the PWPS, the welder welds the test coupon. All the actual welding variables used are recorded along with the results of the test required to qualify the WPS that will be used in production. The information recorded is "actuals", not what the welder should have used.
Assuming the PQR passes all the required tests, a WPS to be used in production is developed. The ranges for the base metal thickness, weld sizes, etc. are based on the information recorded on the PQR. The ranges permitted by the WPS are defined in Section IX. In some cases more than one PQR is required to qualify the full range of base metal thicknesses required for production.
Best regards - Al
RE: WPS/PQR
RE: WPS/PQR