Skip to main content

[MW:2503] Re: No Defect Revealed procedure ?

By Materials & Welding
Hello,
 
Calculate exposure time for average thickness for expample, base matl thk is 30mm, grinded up to 14mm calculate exp time for 20mm.
 
or
 
As per my Former boss Shri. H.V.SrivastavaJI, use D7 & D4 film. Keep first D4 and D7 remove D7 and process the film after complete exposure time.
 
D4 film process after giving 3.3 times of D7 exposure and process you can see everything.
 
S.Senthilkumar

--- On Sun, 21/6/09, israr <ahmedisrar.nm@gmail.com> wrote:

From: israr <ahmedisrar.nm@gmail.com>
Subject: [MW:2499] Re: No Defect Revealed procedure ?
To: "Materials & Welding" <materials-welding@googlegroups.com>
Date: Sunday, 21 June, 2009, 11:09 AM


Dear Mr Prem,

Pls carry out UT to find out the depth and remove the weld metal until
the depth do the DPT this is only the best method to repair the
defect

On May 4, 9:44 am, Chaitanya Purohit <chaitanya_puro...@yahoo.co.in>
wrote:
> Dear Prem,
>
> During RT you need to consider the exposure for the remaining thickness only i.e 35 -15 = 20 mm. This will give you the radiograph which you can interpret at least to find out the slag. Another thing shall be considered is make the grove wider instead of sharp V grove (after back gouge/grind make a "U" (nearly flat at the bottom) which will again help to get the good radiograph.
>
> Another method is UT... but again the UT operator shall be skill to find out whether the echo is coming from the sharp edge of the grove or from the slag...and echo pattern also will help to identify the slag or sharp edge of grove..
>
> I am not the (hands on) NDT expert but this is what we discuss and do generally when we have problems..like you have.
>
> Other NDT experts are there around the group and I am sure they will give better views on this..I also will prefer to learn the better techniques available and followed..
>        
> CK
>
> --- On Sat, 2/5/09, PREM SHANKARDUTT NAUTIYAL <prem_nauti...@rediffmail.com> wrote:
>
> From: PREM SHANKARDUTT NAUTIYAL <prem_nauti...@rediffmail.com>
> Subject: [MW:2080] No Defect Revealed procedure ?
> To: materials-welding@googlegroups.com
> Date: Saturday, 2 May, 2009, 8:47 PM
>
> Hi Friends
>
> Can anyone guide me about how to carry out NDR (No defect Revealed)procedure for Repair Welding.
>
> The matter is:
>
> We have a circ. seam of two shells ,1m OD,35mm thick.Material Alloy Steel (marine steel).Double V butt joint welded by SMAW.
>
> We landed up in a slag inclusion after RT.
>
> Now by UT we found out the depth of slag i.e 10mm from top and length 100mm. So we grinded upto a depth of 14mm from top. Then we conducted RT for ensuring No Defect was Revealed or Present.
>
> But surprisingly the RT film was just dark with lot of density variations and we could not confirm whether the defect (slag) was removed or not as it was difficult to interpret the radiograph.
>
> Now can anyone help me out : How do we ensure by Radiography that the defect is removed after grinding. i.e how do we conduct Radiography of such partially grinded areas.
>
> Also the material can be repaired only twice, hence i want to confirm that the slag at depth of 10mm is completely removed before welding.
>
> Are there any other NDT method for doing NDR for repairing welds ?
>
> Regards
>
> Prem S Nautiyal
>
> Cell:9820313278
>
> PREM S NAUTIYAL
>
> CELL : 9820313278
>
>       Own a website.Get an unlimited package.Pay next to nothing.*Go tohttp://in.business.yahoo.com/

Love Cricket? Check out live scores, photos, video highlights and more. Click here
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
-~----------~----~----~----~------~----~------~--~---

Comments

Post a Comment

Popular posts from this blog

Materails FAQs

By Materials & Welding
Q: What are equivalents for standard Q 235 B (and Q 235 A) for U-channels? (asked by: boris.vielhaber@vait.com) A: DIN Nr. = 2393 T.2, 2394 T.2, EN 10025 W. Nr. DIN 17007 = 1.0038 Design DIN 17006 = RSt 37-2, S235JRG2 (Fe 360 B) Q: What is St DIN 2391 BK material? (asked by: dmcandrews@automaticstamp.com) A: Precision steel tubes, cold-finished/hard. Q: What is C.D.W. Boiler Tube? (asked by: montydude123@yahoo.com) A: Cold Drawn Welded Boiler Tube. Q: WHAT IS W.Nr. 1.4301? PLS TELL US IN EASY LANGUAGUE (asked...
21 comments
Read more

Heat tint (temper) colours on stainless steel surfaces heated in air // Heat tint

By Materials & Welding
Introduction The colour formed when stainless steel is heated, either in a furnace application or in the heat affected zone of welds, is dependent on several factors that are related to the oxidation resistance of the steel. The heat tint or temper colour formed is caused by the progressive thickening of the surface oxide layer and so, as temperature is increased, the colours change.   Oxidation resistance of stainless steels However, there are several factors that affect the degree of colour change and so there is no a single table of colour and temperature that represents all cases. The colours formed can only be used as an indication of the temperature to which the steel has been heated. Factors affecting the heat tint colours formed Steel composition The chromium content is the most important single factor affecting oxidation resistance. The higher the chromium, the more heat resistant the steel and so the development of the heat tint colou...
Post a Comment
Read more

Re: [MW:10788] ON PLOT PIPING & OFF PLOT PIPING

By Materials & Welding
Piping systems involved for the flow lines and gathering lines from the well head isolation valve to the production facility or processing plant isolation valve are determined as OFF PLOT. ON PLOT defines piping system in the processing plant and production platform. ANSI/ASME B31.4 applies for off plot piping system. B31.4 allows the use of either API 1104 or ASME section IX (as appropriate). However, occasionally, a very small system such as piping within 500 feet of a processing plant (some client also said 400 feet) may be declared B31.3 rather than B31.4. When B31.3 is invoked, only ASME Section IX is used. before you decide which code to use for welding procedure and/or welder qualification for pipe welding, you have to know the design and construction code applicable to the system. Please read far enough into scope and diagram illustrating the application of either B31.3 and B31.4 hope this helps rgds 2011/4/21 pradip kumar sil < pradipsil@gmail.com > Dear all, ...
Post a Comment
Read more