percentage of x-ray welds PED lines

[europipe]

Does anyone know what is mostly used for percentage x-ray of pipelines for PED cat.I,II and III ?
Your help would be greatly appreciated.

 

[Giuss]

I think you refer to % of RT of field circumferential Butt Welds.
Even if PED 97/23/EC doesn't clarify the extent of RX during erection, my approach is to specify 10% as minimum (while according to ASME B.31.3 i specify 5% as minimum for projects outside EU.
I made this decision following several No.Bo. indication.
This should come from EN-13480 and other relative EU STD's.

Giuss

 

[europipe]

Giuss, thanks for your reply and sorry for my poor use of the English language.
The company I now work for uses the next percentages:
CAT.I prefab welds 5% fieldwelds 10%
CAT.II prefab welds 10% fieldwelds 30%
CAT.III welds 100%
It's a heck of a job to arrange it all the proper way,
so I wanted to know if it is not overdone.

 

[DSB123]

europipe,
"Does anyone know what is mostly used for percentage x-ray of pipelines ......"

Please note that Pipelines in the true sense of the word are excluded from the PED.

 

[europipe]

again, sorry for my poor English,
What is the correct word then?

 

[DSB123]

europipe,
The word "pipelines" is associated with lines deemed outside of plant boundaries (i.e. overland lines, subsea pipes and the like ) which are designed to Codes such as B31.4 or B31.8 etc. In plant systems are generally termed "pipework" or "piping" systems.

 

[europipe]

?,

My English is terrible, but I think that's not right.
But we're straying off the subject.
Someone has other percentages for me?

 

[Giuss]

Europipe,
I wrote about MINIMUM RT extent;
but i can't see a relation beetween % RT and PED Category.
I don't know which is your work procedure, i specify %RT for Piping Class, mainly according to Base Material, Service and Rating.
So, the first point is: when a piping class is linked to Lines from different PED category, how do you manage it?
Second Point: Ped Category is determined by Fluid Group, Pressure and Diameter, so you could have a line category II or III for a no dangerous service only becouse of large sizes and/or pressure using Carbon Steel, in this case you will require 100 % of RT, while just a 10-30% for a Low alloy becouse line diameter are small????
I think this makes no sense, the extent of RT cannot be done to PED categorization but on material, fluid and rating.

Giuss

Giuss

 

[europipe]

Giuss, You are right about the 2nd point, but there are not much lines in cat II and III that are not dangerous.
(high press. and or gas conditions at atm. press.)
Also when dia x press. is low(with small diameter or press.)the line is not as dangerous as with high dia x press.
I think it makes sense but I doubt the quantity of photo's taken.
Thanks for your valuable input although.

 

[DSB123]

europipe,
I think you need to get hold of the PED Documentation and read it. your original question quotes "pipelines" which as I have said before are excluded from the PED.We are not "straying off the subject" as you put it. Pipelines are exempt so you should not be using "pipelines" and PED in the same discussion.

 

[europipe]

DSB, STOP, I know for about 30yrs. what pipelines are.
I know about 6-8 years what PED means.
A plant doesn't consist of pipework but lines.
You also say lineschedule not pipeworkschedule.'
Please, This is not what I asked

 

[Giuss]

Europipe,
I made it short, but i'm going to say better with an example what i mean:
I have two lines with following conditions:
First Line: Alloy P11 or P22
-Fluid Group according to PED.: I
-P des: 15 bar
-T des: 465 °C
-Size: 4''
-Ped Category: 2
-Material (low Alloy steel 1,25Cr or 2,25Cr material is selected on T design basis)
According to your Std, i'll require 30% of RT on field circumferential Butt Welds.

Second Line: A106 Gr.B
-Fluid Group according to PED.: I
-P des: 18.5 bar
-T des: 275 °C
-Size: 4''
-Ped Category: 3
-Material Carbon Steel
According to your Std, i'll require 100% of RT on field circumferential Butt Welds.

Sincerly, does it make sense?
I'll say: 10% for the second line and 100% for the first one, and if the above mentioned example will involve a P91 with a Tdesign>500°C??? You'll require 30% only becouse it's category II according to PED????

About your question with DSB123:
i think it is just a ''wording'' (you mean piping) matter, anyway he is rigth:

From Article 1:

2.1.2. 'Piping` means piping components intended for the transport of fluids, when connected together for integration into a pressure system. Piping includes in particular a pipe or system of pipes, tubing, fittings, expansion joints, hoses, or other pressure-bearing components as appropriate. Heat exchangers consisting of pipes for the purpose of cooling or heating air shall be considered as piping.

3. The following are excluded from the scope of this Directive: (See Guidelines: 9/7)

3.1. pipelines comprising piping or a system of piping designed for the conveyance of any fluid or substance to or from an installation (onshore or offshore) starting from and including the last isolation device located within the confines of the installation, including all the annexed equipment designed specifically for pipelines. This exclusion does not apply to standard pressure equipment such as may be found in pressure reduction stations or compression stations; (See Guidelines: 1/17,1/18,1/28,1/29,1/31,1/32)

Giuss

 

[DSB123]

europipe,
Do you understand that using capitals is equivalent to "shouting" at someone which is rather irregular in these forums. All I have tried to do is educate you into the fact that to use the term "pipelines" and the PED together is incorrect. If you cannot accept this then you are on your own mate.
It's all about getting the engineering terminology
correct so you ge tthe correct answer.
Just for your information I have never used the term lineschedule or pipeworkschedue as these are not "english".

 

[europipe]

DSB, Maybe lineschedules or linelists with a special columns in it for PED issues are "American and Dutch" then cause I worked for USA companies and Dutch companies for many, many yrs, is the name not used in England? (and yes I really wanted to shout to you, my excuses).
Do you have any experience with x-raying of buttwelds at site, please respond.
Guiss, I'm not saying I made this rules, that's why I asked this question about x-ray, Í appreciate your input very much.

 

[europipe]

Guiss,I checked Your examples but I came for both lines at
PED cat.II.
Here is a nice determination program;

For calculation and category;
Click on the grey rectangular picture left of:
"Klik op de afbeelding hiernaast om het programma te downloaden."
When You run the program, You can choose the english version

http://www.stoomwezen.nl/

 

[Giuss]

Ok,
Europipe it was just a typo,
the second line is 8'', or you can arise the pressure....... anyway nothing changes,
...i'll still remain: 100% first one and 10% for the second one....
Again:

% or RT should be based on:

-Fluid Dangerousness
-Probability of weld defects strictly depending on the metallurgy of the involved materials.

If a No.Bo asks you for a minimum extent, it'ok, but that PED categories determine your choice is another matter.

Giuss