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09:02 Aug-03-2006
Jacky
Density

EN 1435 requires that the density in the area of interest be 2. What is the meaning of the area of interest- the root area, the cap area, the HAZ area or the parent material? The IQI is based on the parent material without taking into consideration the weld reinforcement.
In our case we have 50% more material in the weld area(total thickness of the weld 13 mm) than in the parent material ( 8.5 mm ). Where do we measure the density?


 
00:58 Aug-03-2006
DJ Kallhof
Re: Density I don't know about you but I am responsible for the basemetal as well. I also seem to recall working to codes that allow for re-enforcement to be factored in for IQI selection. You also might want to check the visual requirement for re-enforcement, they might have exceeded it so you don't even have to shoot it.
----------- Start Original Message -----------
: EN 1435 requires that the density in the area of interest be 2. What is the meaning of the area of interest- the root area, the cap area, the HAZ area or the parent material? The IQI is based on the parent material without taking into consideration the weld reinforcement.
: In our case we have 50% more material in the weld area(total thickness of the weld 13 mm) than in the parent material ( 8.5 mm ). Where do we measure the density?
------------ End Original Message ------------




 
02:55 Aug-04-2006
david
Re: Density API 1104 (as an example) states that IQI selection shall be based on the thickness of the weld (defined as nominal wall thickness plus the weld reinforcement (internal and external combined)).
Density range in the area of interest 1.8 - 4.0. Does EN1435 not allow a range? You could shoot for the weld centre to be 2.0 and the parent material to be at the top of the density range. Not ideal for interpretation but legal.

Area of interest (should include any areas you could get defects that may cause the joint to fail) normally the weld and HAZ, so if you cannot keep this area within the density range you may have to get the welders to reduce cap or root, or shoot multi film or exposures. (there are other ways to reduce density range but far easier is to control the weling process)

Remember, as the previous answer implies, you should never shoot anything that has not been cleared on visual first.
Your spec almost certainly differs from the above, I don't have a copy of EN 1435 to reference, 1104 is just one code used as an example.

----------- Start Original Message -----------
: I don't know about you but I am responsible for the basemetal as well. I also seem to recall working to codes that allow for re-enforcement to be factored in for IQI selection. You also might want to check the visual requirement for re-enforcement, they might have exceeded it so you don't even have to shoot it.


: : EN 1435 requires that the density in the area of interest be 2. What is the meaning of the area of interest- the root area, the cap area, the HAZ area or the parent material? The IQI is based on the parent material without taking into consideration the weld reinforcement.
: : In our case we have 50% more material in the weld area(total thickness of the weld 13 mm) than in the parent material ( 8.5 mm ). Where do we measure the density?
------------ End Original Message ------------




 
01:45 Feb-26-2018
Tom burke
Re: Density In Reply to david at 02:55 Aug-04-2006 .

Can I suggest using a plaque type IQI with a shim instead of a wire type ;
Radiographic Density and IQI Sensitivity ASME V
T-282 Radiographic Density

T-282.1 Density Limitations. The transmitted film
density through the radiographic image of the body of
the appropriate hole IQI or adjacent to the designated
wire of a wire IQI and the area of interest shall be 1.8
minimum for single film viewing for radiographs made
with an X-ray source and 2.0 minimum for radiographs
made with a gamma ray source. For composite viewing
of multiple film exposures, each film of the composite
set shall have a minimum density of 1.3. The maximum
density shall be 4.0 for either single or composite viewing.
A tolerance of 0.05 in density is allowed for variations
between densitometer readings.

T-282.2 Density Variation
(a) General. If the density of the radiograph anywhere
through the area of interest varies by more than minus
15% or plus 30% from the density through the body of
the hole IQI or adjacent to the designated wire of a wire
IQI, within the minimum/maximum allowable density
ranges specified in T-282.1, then an additional IQI shall be
used for each exceptional area or areas and the radiograph
retaken. When calculating the allowable variation in density,
the calculation may be rounded to the nearest 0.1
within the range specified in T-282.1.

(b) With Shims. When shims are used with hole-type
IQIs, the plus 30% density restriction of (a) above may
be exceeded, and the minimum density requirements of
T-282.1 do not apply for the IQI, provided the required
IQI sensitivity of T-283.1 is met.

T-283 IQI Sensitivity

T-283.1 Required Sensitivity. Radiography shall be
performed with a technique of sufficient sensitivity to
display the designated hole IQI image and the 2T hole,
or the essential wire of a wire IQI. The radiographs shall
also display the IQI identifying numbers and letters. If
the designated hole IQI image and 2T hole, or essential
wire, do not show on any film in a multiple film technique,
but do show in composite film viewing, interpretation
shall be permitted only by composite film viewing.

T-283.2 Equivalent Hole-Type Sensitivity. A thinner
or thicker hole-type IQI than the required IQI may
be substituted, provided an equivalent or better IQI sensitivity,
as listed in Table T-283, is achieved and all other
requirements for radiography are met. Equivalent IQI
sensitivity is shown in any row of Table T-283, which
contains the required IQI and hole. Better IQI sensitivity
is shown in any row of Table T-283, which is above the
equivalent sensitivity row. If the required IQI and hole
are not represented in the table, the next thinner IQI row
from Table T-283 may be used to establish equivalent
IQI sensitivity

 
08:53 Feb-26-2018

Dr. Uwe Zscherpel

R & D,
BAM Berlin,
Germany,
Joined Jan 2010
67
Re: Density In Reply to Jacky at 09:02 Aug-03-2006 (Opening).

Dear Tom,
if you replace the wire type IQIs by plaque type IQIs you should be aware that especially for higher wall thicknesses (above 2 inches) the requirements for plaque type IQIs are much higher than the requirements for wire type IQI visibility. This is a draw back of an incorrect conversion of wire to plaque IQI visibility inhearent to the ASME code since decades! ASME is not willing to change this...

 
14:15 Feb-26-2018
Tom burke
Re: Density In Reply to Dr. Uwe Zscherpel at 08:53 Feb-26-2018 .

Dear Uwe,
I completely understand what you are saying. I have been using plaque type penetrameters (or should I say Image Quality Indicators) since 1982, and continue to use them today. I have been told that this is very old fashioned by younger technicians who use wire types. The only time that I used wire type I.Q.I.'s was with cobalt where we shot castings in the 2" to 6" thickness range.
I would agree with you that a plaque type is becoming an art, achieving densities and sensitivity by choosing the correct method, penetrameter placement, film type, and proper processing to have all the necessary sensitivity criteria to satisfy the code and the customer.

The new generation of radiographers put a wire on everything.

The common methodology is why would you try to show a single hole 2% of the thickness or 0.010" - 0.040" in size, when you can have six wires of varying thicknesses, 1" or 2" long to shoot at, and you are allowed to put them all in the area of interest.(possibly masking transverse indications)

I have used wires, and have found it virtually impossible not to show the essential wire or thinner wire, even using techniques and film speed that would be practically impossible to show the 2T on an equivalent plaque penny.
Also the wires are easier to see than the hole,and you can use one wire for multiple thicknesses versus a selection of plaque types. 4 wires or 15 different plaques to choose from.

Yes, ASME is way behind in making it a fair game. We should be allowed to use a row of 6 different plaques to make it fair. It would be more appealing to the eye.:)

 
14:26 Feb-26-2018

Dr. Uwe Zscherpel

R & D,
BAM Berlin,
Germany,
Joined Jan 2010
67
Re: Density In Reply to Tom burke at 14:15 Feb-26-2018 .

Dear Tom,
have you looked for ISO 19232-2? I think this is what you are describing, a step/hole IQI with 6 steps....
Greetings
Uwe Z.

 
01:11 Feb-27-2018
Tom burke
Re: Density In Reply to Dr. Uwe Zscherpel at 14:26 Feb-26-2018 .

Dear Uwe
Thanks for the information. I will look into if we can use the the step Hole IQI for weld quality per B31.3 and ASME Sec V for weld quality of piping.


In the meantime going back to the D7 issue;
section V article 2 you'll find this paragraph:
"T-221.2 Procedure Demonstration. Demonstration of
the density and image quality indicator (IQI) image requirements
of the written procedure on production or technique
radiographs shall be considered satisfactory evidence of
compliance with that procedure."

Demonstration of the ""Density and"" being key.

So with that it's been clarified that the intent is to keep densities within the range of para T-285.
It also clarifies this paragraph in the 08 addenda of Section VIII

"(2) A written radiographic examination procedure is
not required. Demonstration of density and penetrameter
image requirements on production or technique radiographs
shall be considered satisfactory evidence of compliance
with Article 2 of Section V."

I would like all experts to now be involved as classification of film is now becoming an international issue.

Apologies for the intermittent replies : working turnaround 84-90hrs per week.

 
01:44 Feb-27-2018
Tom burke
Re: Density In Reply to Dr. Uwe Zscherpel at 14:26 Feb-26-2018 .

Uwe,
I googled the stephole type IQI
Once again, this is a European standard
The hole sizes are different from the astm plaques or wires. The 2t sensitivity on an American IQI would be the 1T on the European step hole type. Causing confusion therefore they are not predominantly used in the US. Therefore many customers have not seen them before and would not be happy to change.

 
17:05 Mar-05-2018

Dr. Uwe Zscherpel

R & D,
BAM Berlin,
Germany,
Joined Jan 2010
67
Re: Density In Reply to Tom burke at 01:44 Feb-27-2018 .

Dear Tom,
if you google for my institute you will find that it is in Berlin, the center of Europe!
Of cause you can convert IQI sensitivities of step-hole IQIs, wiore type IQI and also american ASTM plaques and wires. No problem. There are all equal, but differenet codes instists on different IQIs.
Greetings
Uwe Z.

 


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