PQR

[AIAIAANI]

WPS for nozzle 10 mm thick set-in into shell 26 mm thick. Impact testing is a requirement.
How to prepare PQR test coupon (one or two) to satisfy both t=26 and T 10 and 26?

 

[metengr]

You need to provide more information. Here is some general guidance below;

If the nozzle base material is of the same P-No and Group No as the shell base material, a welding procedure qualified to 26mm base metal thickness (with corresponding weld deposit thickness) will cover the lesser nozzle thickness.

If the nozzle is of a different P-No or Grade No base material (for impact testing) in comparison to the shell material, you will need to qualify a weld procedure for the nozzle base metal thickness and shell base metal thickness at 26mm.

ASME Section IX, QW-451.1 provides the requirements for base metal and weld deposit thickness ranges for procedure qualification. For your application, it appears that you will need to obtain shell base material at 13mm thickness to cover the maximum of 26 mm (2 times the coupon thickness). However, for the nozzle you are right on the edge, and it would appear that the you will need to obtain 13mm thick nozzle material for the weld procedure qualification to cover the base metal thickness range for the shell (26mm).

Qualify the weld procedure for your desired welding processes using the supplementary essential welding variables (for impact testing) in accordance with ASME Section IX, QW-250.

 

[weldtek]

Sometimes it makes sense to qualify a separate plate for impacts only, on material of a thickness which will cover the thinner of the materials to be joined. In this case a weld test plate 10 mm (3/8") thick, tested for impacts only, combined with a test plate 16mm (5/8") thick tested for tensiles and bends will cover you for impact tested applications from 10mm (3/8"), through 32mm (1 1/4").
You may even have an existing PQR without impact testing, which you could use in combination with the impact tested only plate.

 

[AIAIAANI]

Thanks Metengr. But I am still baffled. Material of nozzle and head is all the same PNo.1 Gr.1.
Please consider that supplementary essential vaiables enter in force, being impact tested.
Thus T (Base Metal thk) minimum qualified is the minimum of the PQR. If I use a 13 mm coupon it will not qualify for the 10 mm BM thk. of the nozzle. If I use a 10 mm to 13 mm coupon I would be qualified fot the two BM thk but I can only obtain a weld of 10 mm which qualifies for t (w.m.thk.) max. of 20 mm.
The only chance would be preapare 2 samples one 10 mm to 10 mm BM and another 13 (or more) to 13 (or more) mm. but each of them fails to satisfy both BM thk. of the joint.
Mauro.

 

[metengr]

Mauro;

Material of nozzle and head is all the same PNo.1 Gr.1.
Please consider that supplementary essential variables enter in force, being impact tested.
Thus T (Base Metal thk) minimum qualified is the minimum of the PQR.

Ok, having the additional information helps. First, does the nozzle base material thickness of 10mm require impact testing? The shell material and weld is understandable based on the 26mm thickness for a full penetration weld. Have you verified that the nozzle thickness requires impact testing or is exempt based on UCS-66?

 

[AIAIAANI]

Yes, impact testing is required (MDMT -49 °C) for both materials. Mauro

 

[metengr]

Ok, then. Follow the advice in weldtek's post.