PIN HOLE on SSAW API 5L Pipe.

[CREERAAM]

Hai Experts,

Here Attached the Photo of an API 5L Gr.B Pipe. While checking the Weldments by Visually Pinhole found on the weldment. I was instructed to welder to grind pinhole affected weldment particular 50-60 mm of distance and carry over the welding. My doubt is it's ok? It affect in future?


Information of Pipe

API 5L Gr. B SIze 1000 mm SCH XS(12.7mm) SSAW Pipe. Depth of the Pinhole 6-7 mm

Service Chilled water Cooling line the pipe is pre insulated in shop after welding.



REGARDS,

G.SRIRAM.

Dream,Dream,Dream Dream transforms in to thoughts.And thoughts result in action

 

[metengr]

Perform surface NDT to ensure no cracks in material surrounding the pin hole. Once this step is completed, you can carefully bridge the pinhole and weld restore the excavation. I would recommend GTAW for closing the pin hole and once this is completed finish with your welding process.

 

[racookpe1978]

Well, it is already ground through to the interior of the pipe, and the weld itself around the "used-to-be-pinhole" does not "appear" to be cracked, but it might be.

1. Remove ALL the remaining paint (primer ?) or galvanized ? from at least 1-1/2 to 2 inches around the weld repair area. You will never be able to get a good weld if the heated area around the repair weld is contaminating the new melted metal and base around the repair. (Also, the paint must be removed to recoat the repair, or you'll rust out the pipe at the repair spot. Your welder - probably the guy who created the pinhole in the first place needs more shop discipline. His foreman AND his foreman's supervisor needs more discipline too ! )

2. Do a dye penetrant exam of the repair to verify the newly exposed area is clean of cracks, remove the extra paint/primer around the repair, then do the weld repair per original WPS. Repeat the PWHT and the Pre-heat if they were required in the WPS.

 

[CREERAAM]

Dear racookpe1978 & metengr.


Thanks for the reply. i was carried the Grinding to the extent of pinhole found and carried visual inspection and welded in SMAW.


G.SRIRAM.

REGARDS,

G.SRIRAM.

Dream,Dream,Dream Dream transforms in to thoughts.And thoughts result in action

 

[DekDee]

Was the defect in the original pipe weld or in your site weld ?
You say depth of pinhole was 6-7 mm but it clearly goes right through the wall thickness (12.7 mm) ??
What was the original welding process ?
Do you have a qualified WPS to perform the SMAW weld repairs ?
Regards,
Shane

 

[CREERAAM]

Dear Mr.DEKDEE,

Thanks for your valuable reply

The pipe manufactured in shop of my supplier by SAW PROCESS(SSAW pipe). I was checked by visually through out the grinding process it upto only 6 mm-7 mm only the pinhole. Original welding process was SAW. Yes we have qualified welder but no WPS due to we are insulation company only. we don't have welding engineer or welding inspector but am quality person so i don't want insulate as it is that's why we carried welding manually SMAW Process.



REGARDS,

G.SRIRAM.

Dream,Dream,Dream Dream transforms in to thoughts.And thoughts result in action