Insulating Kits for Flanges Between Carbon Steel and P11 Alloys

You would need the all of the information regarding fluids or gases flowing in pipe, pressures encountered, temperature ranges, design life etc...the gasket material to avoid electrolysis would also need to be non-conducting material of a sufficient thickness to meet the spec...all these factors must be considered as well as operating environment...

https://www.tiogapipe.com/newsletter/issue2_p_grades.aspx

https://stepko.com/flange-isolation-gasket-kits/

Insulating gaskets sets are used for isolation of underground piping Transistions to above ground piping. They must be isolated to prevent corrosion cells from creating galvanic corrosion.

Any piping supply house servicing the oil patch will have them.

I also used mica gaskets to insulate piping in which in which we ran electrical current to heat the pipe and it’s contents.

Hi experts, thanks for leads.the fluid used are either inhibited water or heating oil; both used as heating medium in a heat recovery unit.

is that of any help to the question?

lum

If you don't have any information about the installation design, how do you expect to spec parts? Your original question seems to ask, is the gasket necessary?, to answer that question requires information about the installation...What exactly is your role here? Are you a student?

Not really, because <...inhibited water...> and <...heating oil...> are fluids with significantly different properties: electrical conductivity, and the associated potential for corrosive action on the wetted materials, being only one of them.

Why different materials are in contact with these fluids at any time is something of a mystery to the forum, as is the need for a material specification change while in contact with either of them.

Further, there is no mention of either temperatures or pressures, or the pH of the <...inhibited water...>. These things are fundamentally important in the design of any plant or the selection of materials of construction.

The best advice is to go back to the proverbial "horse's mouth", and ask there.

Thanks solar eagle.

I have no more comments.

Lum

Consider this link as well:

https://www.materials.sandvik/en/materials-center/corrosion/wet-corrosion/galvanic-corrosion/

thanks Redneck,

mush appreciated.

Lum

The <...ruling...> comes from the individual who <...asked...>. Ask that individual for the reasoning behind it. A bunch of anonymous strangers on a global internet Engineering forum is not going to be a better, or a quicker, source of information than that.

hi PW,

Unfortunately, the engineer whose organisation specified the clause could not provide a clarification.

since the last pose, the answer was in the site on galvanic corrosion from wikipedia.

carbon steel and p11 has the same volt potential and is therefore not subject to galvan9c corrosion.

thanks all for the comments.

lum

I disagree...

https://www.npl.co.uk/special-pages/guides/bimetallic-guide.pdf

So it looks like the proverbial “blind leading the blind”. ��

https://www.apsonline.com/gasketkits

As I stated previously, any reputable piping supply house will be able to sell you an insulation gasket set. See link above for an example. These gaskets are used to prevent galvanic corrosion cells creation especially with underground pipelines mating up with above ground piping.

Call your supply house