Retest of Production Test plate for vessel

Question

Retest of Production Test plate for vessel

ahmadire (Mechanical)

(OP)

6 Sep 17 11:18

Dear experts,
If in process of welding pressure vessel the Impact test of PTP get failed to pass, can we select a new plate? in this situation that the test plate has not been heat treated and fabricated along with the main product!

BenStewart (Mechanical) · Answer 1 · 2017-09-06 11:59:12

Which code has your vessel been designed to and what are the materials of construction?

Why would you want your PTPs to not reflect the heat treatment your vessel has seen? Some codes have means of waiving the requirement for a PTP, i.e. Annex D D.7.2.2 of PD5500, but a project specification may govern and mandate PTPs.

david339933 (Industrial) · Answer 2 · 2017-09-06 13:33:49

ASME Sec. VIII Div. 1 - UG-84(j) - "If the vessel test plate fails to meet the impact requirements, the welds represented by the plate shall be unacceptable. Reheat treatment and retesting or retesting only are permitted".

Material must be from one of the heats used in the vessel.
Shall also be welded at the same time as the vessel, or as close to the start of welding as possible.

Sec.VIII only....as you don't state a construction code.

ahmadire (Mechanical) · Answer 3 · 2017-09-07 04:38:30

The Material is A516-70 and the construction code is ASME VIII Div 2.
Since the PTP is tested after PWHT of vessel, after failing the Impact test the vessel has been fully fabricated and there is no Plate of the same heat which vessel has been made of.

SnTMan (Mechanical) · Answer 4 · 2017-09-07 14:40:54

ahmadire, first thing you need to do is see what Div 2 requires. Second, sometimes the material supplier can supply additional material from the same heat, if you don't have any left.

You may be in big trouble here...

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

ahmadire (Mechanical) · Answer 5 · 2017-09-08 13:49:30

can we use article 2.1 of pcc2? and cut out an area of a seamweld for retesting?

david339933 (Industrial) · Answer 6 · 2017-09-08 15:17:25

PCC2 is for in-service vessels......you have not completed fabrication.

r6155 (Mechanical) · Answer 7 · 2017-09-08 17:01:59

ahmadire
Where is inspection plan, QA system, welding engineer?

Regards
r6155

pradipgoswami (Materials) · Answer 8 · 2017-09-08 18:35:57

Hello Ahmadire,

Please see the following clause of Sec-VIII, DIV-2, which allows re-test to be permitted. One need to read through all the appropriate clauses get the right direction.
To summarize code allows Re-Test on the same coupon plate.

3.11.7.6 Retests.
(a) Absorbed Energy Criteria – If the absorbed energy criteria are not met, retesting in accordance with the applicable
procedures of SA-370 shall be permitted.

Thanks.

Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario,Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299

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