Production Impact Test Plate for Repair Welds

[newweldeng09]

I have two potential weld repairs.
Repair No. 1: I have welded a Category A joint with the SAW welding process. It was determined by UT that there is linear indication about 1/8 in. under the service and about 2 in. long. I was considering repairing it with FCAW, however since it is Category A, per UG-84(i)(1), I would have to run a production impact test plate using the FCAW process. Is this a correct interpretation? Also, the vessel thickness is approx. 8 3/8 in. thick. Do I have to weld this thickness for the production impact test plate or can I use a smaller thickness, such as 1.5 in., test plate?

Repair No. 2: There are small repairs on base metal of this vessel on a bevel preparation. The bevel preparation on one vessel will be welded to another bevel preparation on another vessel to create a Category B weld joint, which would require a production impact test plate at the time of welding this joint per UG-84(i1). Would I need to perform a production impact test plate to perform these repairs on a bevel preparation prior to it becoming a Category B joint? (Note: I understand that I can use the production impact test plate, if needed, for Repair No. 1 for this repair, if required).

 

[metengr]

I was considering repairing it with FCAW, however since it is Category A, per UG-84(i)(1), I would have to run a production impact test plate using the FCAW process. Is this a correct interpretation?

Yes.

Do I have to weld this thickness for the production impact test plate or can I use a smaller thickness, such as 1.5 in., test plate?

You can qualify for a partial penetration weld deposit thickness needed for repair on 1.5" thick coupon, see QW-202 (b)

(b) Qualification for Partial Penetration Groove Welds.
Partial penetration groove welds shall be qualified in accordance
with the requirements of QW-451 for both base
metal and deposited weld metal thickness, except there
need be no upper limit on the base metal thickness provided
qualification was made on base metal having a thickness
of 11/2 in. (38 mm) or more.

Use the above for any weld repairs.

 

[newweldeng09]

I have already qualified this procedure. What thickness is required for the production impact test plate? Do I have to weld a 8 3/8 in. thick test plate with the FCAW process for this repair weld or can I weld a 1.5 in. thick production test plate with the FCAW process to meet the intent of UG-84(i1)?

 

[metengr]

You can qualify on 1.5" thick plate because this is a partial penetration repair weld not a full penetration weld.

 

[bpv66]

I am no expert with impact test requirements, however UG-84(i) states that the impact test plate shall be from one of the heats of steel used for the vessel. If practicable, the test plate shall be welded as an extension to the end of the production joint for Category A joints. I'm not seeing anything in UG-84(i) that would permit a 1.5" test plate for 8.375" shell.

In my opinion, the test plate needs to be the same thickness and from the same heat as the shell material.

 

[metengr]

bpv66;
I was looking at Section IX, QW-202 (b) to qualify as a partial penetration weld, aka repair weld. The test plate must be of the same heat but does not need to be full thickness.

 

[bpv66]

Metengr,

QW-202.2(b) only applies to welding procedure qualification, which allows you to use a 1.5" thick test coupon to qualify the WPS. It appears the OP already has qualified a welding procedure for FCAW.

UG-84(I) applies to production impact test plates. UG-84(g) clearly indicates that impact test plates are in addition to the procedure qualification test plates. Two different plates with different requirements. The way I read it, UG-84(I) requires that impact test plates to be the same thickness and come from the same heat as the vessel component.

Newweldeng09: Have you discussed this with your AI?

 

[metengr]

I did not think he had a FCAW qualification for the above, which is why I suggested going the route of QW-202 (b) for this material heat. I did not see anything in UG-84 to prohibit it.

I would stick with the SAW for repair versus switching welding process midstream.

 

[bpv66]

Metengr: I agree, the most cost effective method would be to use SAW to perform Repair #1 since that WPS was already qualified with production impact testing.

This reasoning applies to Repair #2 as well. UG-84(I) requires impact tests of welds and HAZ for each qualified WPS used on the vessel. Therefore, you would not need to perform an additional production impact test plate on Repair #2 as long as the WPS for the bevel repair is the same as the one used to make the Category B weld.