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IQI 1B or IQI 1A?

IQI 1B or IQI 1A?

Postby mohd » Sun Oct 19, 2014 8:17 am

Dear all,
Pipe thickness: 5.49 mm,
Material: carbon steel,
IQI 1B was selected based on material thickness plus 2 mm weld reinforcement but the client claims that IQI 1A shall be used and thus reshoot shall be done.
Could you please advise if that reshoot is required or not?

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Joined: Mon Jul 08, 2013 2:17 pm

Re: IQI 1B or IQI 1A?

Postby Shridev » Sun Oct 19, 2014 6:13 pm

Dear Mohamed,

The ASME V, par. T-276.2 (a) specifies: The thickness on which the IQI is based is the nominal single-wall thickness plus the estimated weld reinforcement not to exceed the maximum permitted by the referencing Code Section. Backing rings or strips shall not be considered as part of the thickness in IQI selection. The actual measurement of the weld reinforcement is not required.

Now in your case thickness is 5.54 + 1.6 mm (check) = 7.14 mm. If you refer on table T-276, the selected wire type essential wires are "6" (source side) and "5" (film side).

As per table T-233.2 both "set A" and " set B" include the wire with identity "6". For double wall double image (DWDI) technique on pipe only source side placement of IQI allowed.

As long as "set B" IQI was used and visible wire had to be 6, then the required sensitivity was achieved. Acceptable if source side IQI was used.

Both "set A" and " set B" IQI can be used if required 6 wire source side, and "set B" for film side.

Please check the applicable design code, ASME B31.3 or ASME VIII, etc, for the maximum permitted weld reinforcement.

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Joined: Sun Oct 19, 2014 5:45 pm

Re: IQI 1B or IQI 1A?

Postby Ballbearing » Thu Oct 01, 2015 2:23 am

This is a very old post but thought I would respond in case it helps someone in the future.
5.49 mm WT as noted in the OP is for 80 NB (88.9 mm OD) and this can be shot DWDI (IQI source side) or DWSI (IQI film side).
This size pipe is usually shot DWSI.
In answer to Mohd's question:
If DWDI - no re-shoot required (if No. 6 wire is visible)
If DWSI - reshoot is required as minimum size wire on 1B IQI is No. 6 and ASME V requires wire No. 5 to be visible,
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Joined: Wed Jun 12, 2013 10:11 pm

Re: IQI 1B or IQI 1A?

Postby Ramesh Barot » Sun Mar 20, 2016 4:10 am

I think we should not add reinforcement in T-276 because it was already added and given in T-276. 2% of effective thickness sensitivity required. If we calculate it 5.49+1.5=6.99 thk. 2% of 6.99 will be 0.1398 mm~ 1.4 mm. Which is nearest wire no.3. But in T 2.76 upto 6.4 mm it is given max i.e. wire no.5 and 4.

If wrong please correct me.

Ramesh Barot
Ramesh Barot
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Joined: Wed Aug 14, 2013 9:04 am

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