Painting on Cold insulated piping
Painting on Cold insulated piping
(OP)
Dear Sirs,
We have a Low temperature piping but it was not insulated. The pipe was painted with Zinc based paint. Now we are planning to insulate the pipe using Cold insulation. Is there any chances of "Corrosion under insulation". The design temperature is (-50 Deg. C). Please give your opinion. The piping is curently in service. Piping material is LTCS (A333 Gr.6)
Regards
Shiny
We have a Low temperature piping but it was not insulated. The pipe was painted with Zinc based paint. Now we are planning to insulate the pipe using Cold insulation. Is there any chances of "Corrosion under insulation". The design temperature is (-50 Deg. C). Please give your opinion. The piping is curently in service. Piping material is LTCS (A333 Gr.6)
Regards
Shiny





RE: Painting on Cold insulated piping
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Painting on Cold insulated piping
Try studying this standard, particularly footnote E to Table 2, to gain an insight into what you might do with the existing coating.
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.
RE: Painting on Cold insulated piping
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Painting on Cold insulated piping
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.
RE: Painting on Cold insulated piping
Thank you very much for your replies.
It is an existing piping. The operating Temp is (-27 Deg. C). It is in use for around two years. It was considered as intermttent service piping initially. Now it is going to be a continuous service piping as we are going to tie in with another pipe. No change in service conditions. As it was considered intermittant service no insulation was provided and "Inorganic zinc rich primer + Micatious iron oxide epoxy + Polyurethane enamel" was applied. It is an above ground piping running on a pipe rack inside the plant. As it is in the running plant we can not remove the paint. For installing another new piping require shut down and is a lengthy process.
So we are thinking of applying cold insulation with out removing the existing paint.
In case of new piping insatalled, what kind of painting shall be applied before installing the cold insulation?
Please give your openion.
Regards
Shiny
RE: Painting on Cold insulated piping
RE: Painting on Cold insulated piping
I would like to recommend the CINI manual for industrial insulation, which has a detailed specification for cold/cryogenic insulation: www.CINI.nl
If you are planning to insulate on a live running pipe I’m wondering whether you need to cope with icing on the pipe. If so I assume you need to remove this before start lagging. I can recommend to use a petrolatum gel on the pipe prior to start installing your fist insulation layer. This gel gives you a time window of a couple of minutes in which no icing on the pipe will occur.
Since it’s an existing pipe that wasn’t insulated I also would pay special attention to the pipe-supports. Can they accommodate the needed insulation thickness? I also would recommend if possible to install cold-bridge free pipe supports.
Regards,
Johan Sentjens
www.linkedin.com/in/johansentjens