radiography requirments for pipes.

[unclebensrice]

Hi there,

So I was just wondering what is the extent of radiography for process piping and piplines in a sour service environment?
I know that B31.3 classifies pipes according to fluid service (i.e. M, D, Normal etc.) but im still vague about the following.

1. Purely gas service process piping.
2. cross country pipelines (above vs underground).

I'd really appreciate it if someone can help shed some light on the above. Sorry for the trouble people

giermo
middleast.

 

[pennpiper]

1. Purely gas service process piping. If the Client designates thew project as a ASME B31.34 Project then ALL the piping is B31.3 (except Boiler Code Piping right at the Boiler)


2. Cross country pipelines (above vs underground). Cross country pipe Lines fall under ASME B31.4 or B31.8 depending on state of the commodity (Gas or Liquid)

 

[zdas04]

And, ASME B31.8 refers that question to API 1104.

David

 

[unclebensrice]

Thanks guys,


Appreciate the prompt reply penn and zdas

So basically speaking i can find out my x ray extent for gaslines and pipelines from api 1104 right?

The thing is I've perused api 1104 for the above ground and underground radiography requirements but to no avail. Can you point me as to where i can find these in the subject code?? thanks again really

 

[blacksmith37]

API 1104 (Sept 1988 ed.) , Par.5.1 ;"The frequency of inspection shall be specified by the company". And I doubt that MR 01-75 (ISO 15156) will help ,as "it is not a quality control document".
Let your conscious be your guide ! But have a QA plan that sounds good if there is a problem.

 

[unclebensrice]

Thanks blacksmith,

but its not so much the frequency of inspection that was inquiring about as the extent of radiography (i.e. 5 % of welds or 10 % of welds etc. )

In my case like you said all our pipes have to conform to MR 0175 due to sour service and we have:

1. Sour service pipe:100% welds radiographed inside an oil gathering facility and 25% outside the facility
2. For pipes with oil greater than 5% BS&W only 10% of welds are radiographed (inside and outside facility perimeter).

I just wanted to know whether those numbers were derived from a code or not

 

[blacksmith37]

I see no % of weldments required to be inspected in my old API 1104. It implies that for any weld inspected, all of that weld be examined. There may be something in ANSI B.31 , but I do not remember.
Another consideration is where you/company RT 25% of the total number of welds : What is an acceptable rejection rate? For example if you RT 20 welds and 1 requires repair -no furthur action may be required. But : if you RT 20 welds and all fail , you will probably need to RT every weld made by that contractor. I mention this because I have had contractors say that the "company" could not RT any additional welds.

 

[BigInch]

No. The quantity of radiography testing required for pipelines constructed under B31 are specifically stated in the .4 & .8 codes themselves. API 1104 addresses weld quality only.

B31.8 Paragraph 826.2

(b) In addition, a certain percentage of the welds shall
be examined through radiographic examination, ultrasonic
testing, magnetic particle testing, or other comparable
and acceptable methods of nondestructive testing.
The trepanning method of nondestructive testing is prohibited. The following minimum number of field butt welds
shall be selected on a random basis by the operating
company from each day’s construction for examination.
.........
(1) 10% of welds in Location Class 1
(2) 15% of welds in Location Class 2
(3) 40% of welds in Location Class 3
(4) 75% of welds in Location Class 4
(5) 100% of the welds in compressor stations, and
at major or navigable river crossings, major highway crossings, and railroad crossings, if practical, but in no
case less than 90%. All tie-in welds not subjected to a
pressure proof test shall be examined.

B31.4 Paragraph 434.8.5 generally has a 10% minimum requirement, but requires 100% of welds to be inspected

(a) within populated areas, subdivisions, shopping centers, and designated commercial and industrial areas
(b) river, lake, and stream crossings within the
area subject to frequent inundation; and river, lake, and
stream crossings on bridges
(c) railroad or public highway rights-of-way,
including tunnels, bridges, and overhead railroad and
road crossings
(d) offshore and inland coastal waters
(e) old girth welds in used pipe
(f) tie-in girth welds not hydrostatically tested
in accordance with para. 437.4.1

"I am sure it can be done. I've seen it on the internet." BigInch's favorite client.

"Being GREEN isn't easy." Kermit

http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.live.com

 

[unclebensrice]

Yes true big,

API 1104 does't state anything in that regard
B31.3 states it according to fluid classification (i.e. category M 20% random radiography.
B31.8 like you said uses location categorization with location one being the most lenient since it is in sparsely populated area.
and B31.4 like you said is 10 % with 100% for the exceptions you listed above.

Thank you so much guys you've been very helpful
Thanks again big inch :>
BEST OF LUCK TO ALL :>

 

[Duwe6]

Talk to your insurance carrier. Current industry standard is to RT 20-100% of cross-country 1104 piping for liability mitigation. If this line was mine, and if your insurance agent can spell "Sour Gas", 100% of the underground welds outside the plant limity [cross-country stuff] would be UT'd or RT'd. Several thousand $$ in testing versus $10-500MM in liability. Easy decision.

 

[BigInch]

It's True. Codes only prescribe the minimum requirements.

"I am sure it can be done. I've seen it on the internet." BigInch's favorite client.

"Being GREEN isn't easy." Kermit

http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.live.com

 

[jamNauman]

dear guys
thanks for all of u for your responce
regards
ACTUALLY I HAD TO NEED THIS INFO

REGARDS

jAM nAUMAN
mOODY iNTERNATIONAL