Crevice corrosion on pipe at support location 1

[Inspector89]

Support was provided from 20" pipe to 2" lines running parallel with it. At the support strip location on 20" pipe, severe crevice corrosion noted.What is the possible solution to prevent crevice corrosion at support location

https://files.engineering.com/getfi...a171-4f93-865f-e3103a738bbe&file=IMG_8095.JPG

Link

 

[SJones]

https://stoprust.com/technical-library-items/06-pipe-supports/

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[Dhurjati Sen]

Dear Prathap K,

Your link does not work. How do you know it is crevice corrosion? Could be a case of poor painting at the time of commissioning.

Regards.

DHURJATI SEN

https://www.nace.org/people/dhurjatisen

 

[r6155]

Severe crevice corrosion?
When was the last inspection before the current?
Can you send us a picture?

Regards
r6155

 

[weldstan]

What material is the pipe? Same for support material? Has the pipe ben coated and with what coating?

 

[r6155]

Are these pipes installed outdoors?

Regards
r6155

 

[chicopee]

Moisture on the piping seems to be a problem.

 

[SnTMan]

Bigger than a breadbox?

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Inspector89]

Hi guys,

These lines were flare lines, installed outside. Pipe was Carbon Steel A-106 Gr B. This is crevice corrosion.
The support strips were removed and the line was coated.
For the 2" line separate support system has been provided.

https://files.engineering.com/getfi...4d81-47a4-9e93-89d277aa9818&file=Untitled.jpg

https://files.engineering.com/getfi...71f-4bf1-bb78-efeed831d5d4&file=Untitled1.jpg

 

My first reaction is that this is not crevice corrosion. But if it looks like a crevice and corrodes like a crevice, we can call this crevice corrosion.
The is carbon steel exposed to the environment, so isolation is the first strategy. Something more robust than painting over the strap is needed; ingress of moisture was inevitable, as evidenced by your pictures.
I suggest you talk to pipe coating experts for a coating appropriate for your local climate.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[r6155]

It may be that these two parts were painted after being fitted.

Regards

 

[Inspector89]

Now we have removed the support strips and line was coated. No more support strips will be placed as a separate support system is provided for 2" line.

https://files.engineering.com/getfi...d4ee-400f-be5b-109b23cf39ba&file=Untitled.png

 

[MJCronin]

Connect a voltage meter between the pipe and supporting structure.

Any significant voltage ?

Stray electrical currents in a plant can augment and accelerate corrosion at selected locations

MJCronin
Sr. Process Engineer