WPS / PQR - Manufacturer / Contractor Responsibility Vs Value Added Activities

Dear Gentleman,

The two points raised by you are more valuable and often deliberated whenever WPS and PQR are prepared.

But every welding process has no. Of parameters which has bearing on making of weld ment of required properties and classified as essential, non essential and supplementary essential. Even though they are common in broad terms , it may vary to site conditions and project to project depending upon thickness factor, type of weld design, consumables including brand name used etc.

Even though we use particular brand of SS (or) CS electrodes, filler wires for welding P8 (or) P1 materials respectively, due manufacturing variations at respective plant some brands may perform better ( specially in impact requirements) or worst. Again the site conditions may also vary.

We have faced these at times while preparing PQRs for alloy steel and SS materials.

One more point to consider is the third party inspection agency. If PQRs are done grouping these agencies and done by any sub -contractor / main contractor, then they may accept it for other sites also provided there are no major changes. It is left to their discretion. If agency varies they may insist up on a new PQR also.

In my opinion and experience, we have convenienced our clients / third party Inspection Agencies at places and differed making new PQRs. At times we were forced to re do it due to project variations and use of different brand of consumables.

In nut shell with good understanding , we can minimise the PQRs ,but can not avoid it fully.

Sridhar.

Further to what was mentioned earlier , I would like to add further that, any WPS - PQR made will be in the name of a contractor /manufacturer at one particular site and can not be transferred in another's name at another site.. This is if you follow ASME Sec IX Code.

If you are following AWS D 1.1 (or) B 2.1 You can use any pre assigned / approved /qualified WPS & PQR and carry out only Welder's Performance Qualification as per the norms.

Sridhar.

I think all ASME, AWS, API mentioned almost the same that Manufacturer / Contrctor shall have their own WPS/PQR and they have take responsible on welding carried out by them. But what if the Owner will accept the responsible for work carried out themselve but using his ex-Contractor's WPS/PQR? It seems non-value added for the Owner to establish his own WPS/PQR which could be just a copy from the ex-Contractor's WPS/PQR but just to fullfil the requirement as stated in Code?

For me as an Owner to a new plant or project, and even we are following AWS D 1.1 (or) B 2.1 which permits using a pre assigned / approved /qualified WPS & PQR and carry out only Welder's Performance Qualification as per the norms, even that is ok, I have to carry out the required PQRs -at least- before starting any welding operations neither for prefabrication nor for erection.

As I said earlier, If the third party Inspection Agency accepts and agrees with your views, then they can allow you to proceed further without making a fresh PQR. Only a new WPS to be prepared and earlier one attached to it. It is left to you to convince them and if the Agency is same at the new site i.e., from your sub contractor site - to your site. If it a new agency they also can accept it without any prejudice..

As for AWS D 1.1 and B 2.1 If the Client / Agency accepts ( If it is same agency) It is not mandatory but left to the discretion of the Inspector. Only a new WPS to be prepared and earlier one attached to it. Yes, some times they insist upon new PQR, at times they accept the earlier one. It is all depends upon how we present the case from our end.

Sridhar

In my experience, It is always better to do Welding Procedure Qualification for ensuring that the base materials, welding consumables and site conditions of work all produce a reliable piece of weld which is confirmed by the tensile, bend, impact and other tests. Sometimes things go badly wrong due to deficiencies in these parameters which result in costly remedies to be undertaken. It is a big risk to by-pass these procedures although it can be argued that one sample is anyway not going to ensure everything is in order - just as 'one swallow does not make a summer'. But it is safer than doing nothing.

Gents,

It is depend of Specs. Usually when carries out welding on primary structure or process piping, it requires to do new PQR/WPS. But welding on secondary such as handrail or open drain lines it may be used pre-qualified.

Rgds,