SA-516 gr 70

[Hadiabdollahi]

Dear All
I am looking forward to codes or standard specifications which guide me about acceptanse allowense of pressure vessle plates surface condition such as sa516 gr 70. ( for example pitting with diffrente depth on the surface). So kindly let me to know about your knowledge and experience.

 

[r6155]

See SA-20

Regards
r6155

 

[Hadiabdollahi]

In Sa20 we cannot find detail data about this subject. I found En 10163-2 which shows detail about that. But We dont know its possible to use EN standard or not?
Becuse our contractor dont accepet EN standard. So kindly me to know your Idea about this issue
Thanks

 

[r6155]

SA-20
9. Quality
9.1 General—Plates shall be free of injurious defects and
shall have a workmanlike finish.
9.2 Surface Imperfections:
9.2.1 For plates produced from plate-as-rolled, all injurious
surface imperfections shall be removed by the manufacturer.
For plates produced from coil, all injurious surface imperfections
shall be removed by the processor.
9.2.1.1 Shallow imperfections shall be ground to sound
metal; the ground area shall be well faired and the thickness of
the ground plate shall not be reduced below the minimum
thickness permitted.
9.2.1.2 All surface imperfections, the removal of which will
reduce the plate thickness below the minimum thickness
permitted, shall be cause for rejection of the plate, except that,
by agreement with the purchaser, the metal so removed may be
replaced with weld metal (see 9.4).

Regards
r6155

 

[Hadiabdollahi]

Yes, that means all of imperfection must be removed, same mirror؟؟؟
If we have some pitting on the surface that is not sharb and depth of them is so much down, what we do??

 

[SnTMan]

Hadiabdollahi, does your question refer to newly purchased plate, or an in-service vessel?

Regards,

Mike




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

 

[Hadiabdollahi]

Purchase

 

[SnTMan]

Then I'd agree, SA-20 or equivalent.

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

 

[Hadiabdollahi]

That means we cannot use old plate that have small pitting, that thickness of plate with pitting is in the range of telorance??

 

[SnTMan]

Hadiabdollahi, I'd pay attention to the word "injurious" and to the plate specification thickness tolerance.

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

 

[metengr]

Final acceptance of the plate with surface pits is up to the Purchaser if it meets SA-20. In your situation, if the surface pits are round bottom in shape and shallow, and the remaining plate thickness as measured from base of the deepest pits is above the minimum thickness required, you can accept it. Otherwise, you have a basis for rejection.

 

[Hadiabdollahi]

I agree with you.

 

[r6155]

If you are the fabricator of PV is your responsability to consult with your client, he has the right to accept or reject the plate.

Regards
r6155

 

[Geoff13]

I see the word "mirror" used a couple of times above. Carbon steel plates, like SA516-70, never have a mirror finish. Below is a typical pic from our work.

Be careful about asking the customer. If the plate meets SA-20 then there's nothing to ask. But if you ask they will think you believe the plate doesn't meet SA-20 and assume they should reject it.

 

[r6155]

Pitting corrosion is not stoped without surface treatment. Pitting corrosion is injurious and must be eliminated

UG-78 REPAIR OF DEFECTS IN MATERIALS
Defects in material may be repaired, provided acceptance
by the Inspector is first obtained for the method
and extent of repairs. Defective material that cannot be
satisfactorily repaired shall be rejected

@ Geoff13: Where is the ethic?

Regards
r6155