sensitivity of RT, specially 2% 1

[purode333]

Dear sir,
I have 1" pipe having 4.1mm thk, we have taken x ray RT with D4 type film.
We also got the IQI of require type of 5 No. as per ASME sec V table.

But client wants 2% sensitivity.
I want to know whether, 2% sensitivity is mentioned in code any where ?. and how we would achieve it.


Regards
Prasad

 

[JR97]

purode333,

2% sensitivity refers to the penetrameter thickness being 2% of the material thickness. The ASME Code does not specifically list a 2% sensitivity; however, Table T-276 in Section V, Article 2 is roughly based on 2%. I assume the "5" you refer to is wire number 5 which is 0.008 inches (0.08 mm) in diameter. So you do not have 2% sensitivity. 2% sensitivity on a 4.1 mm thick piece would require wire number 1. Wires #1 thru 6 are all encased in Wire Set A, so you have the necessary equipment you just have to see all 6 wires in the set instead of just 2 as required by Section V.

You will have to be very careful about Xray energy level to be sure you can see all the wires.

JR97

 

[purode333]

Thanks sir,

I only wants to conclude that, 2% sensitivity means it refer to the material thickness. i.e. for 4.1mm thk plate, 2% of 4.1mm thk is 0.082mm.

Means we have to show 1st wire of set A.



For example : Means for 12mm thk, code says 7 wire of set B to be seen but for 2% of 12mm is 0.24mm, Means according to 2%, 5 wire is necessary of setA.

Is it correct.

Means there are 2 concept, according to T276 and sensitivity of 2% of metal thk.

Is it correct. pls reply.

Thanks for reply again.

 

[purode333]

Dear sir JR97 (Mechanical),

Pls help to conclude the thread.

also my concept of sensitivity.



Regards
Prasad

 

[DekDee]

Prasad,
Is the 2% noted in your project specifications or contract documents ?
What the client wants and what the client gets can be miles apart if the client has a wish-list that is different than what was tendered on.
If it is B31.3 (which then refers you to ASME V)your graphs are code compliant but maybe not project specification compliant (which overrules the code)
Cheers,
Shane

 

[JR97]

(I will only use mm is this post, re-reading earlier one, I think it got a bit confusing using both mm and inches)

If Thickness = 12 mm, 2% of thickness = .24 mm, per ASME Code, Section V Table T-233.2 the applicable 2% wire would be #5 which is .20 mm diameter. If you were shooting straight Code requirement, you would use Table T-276, which for 12 mm thickness would require #7 wire.

For your original inquiry, Thickness = 4.1mm. 2% of thickness = .082mm. Per Table T-233.1 the applicable 2% wire would be #1 which is 0.08 mm diameter. If you were shooting straight Code requirement, you would use Table T-276, which for 4.1 mm thickness would require #5 wire.

I mentioned Code T-276 is roughly based on 2%. This is more so the case when you get to thicker parts. For example, a 50 mm thick part - 2% of thickness is 1mm. Which would be the #11 wire which is also what Table T-276 specifies. The Code (Table T-276) gets a bit more lenient when thicknesses get thinner as in your examples.

hope this helps, JR97