ambient temp stainless steel piping on carbon steel structure - is teflon necessary ?

Posted by: sam

ambient temp stainless steel piping on carbon steel structure - is teflon necessary ? - 08/25/05 05:50 AM

For ambient temp stainless steel piping on carbon steel structure - is teflon sheet as galvanic barrier necessary ? Where is the electolyte to cause corrosion - is it water vapor in moist air ?

regards

sam
Posted by: SUPERPIPER

Re: ambient temp stainless steel piping on carbon steel structure - is teflon necessary ? - 08/25/05 07:46 AM

1.Rain.
2.Washdown.
3.Leaks.

some clients don't like to see cross contamination on hygenic stainless steel pipework,
which occours with or without an electolyte.

'Rubber'(neoprene) is sometimes used for an isolator.
Posted by: John C. Luf

Re: ambient temp stainless steel piping on carbon steel structure - is teflon necessary ? - 08/25/05 06:16 PM

Neoprene rubber ala gasket sheeting fastened on by Zip ties....
Posted by: sam

Re: ambient temp stainless steel piping on carbon steel structure - is teflon necessary ? - 08/25/05 11:20 PM

Thank You Both. As Neoprene rubber sheet is generally available at site for gasket, it will be a good isolator available for fastening on pipe at support points. Now, many are using SS pipe for drinking water supply even in developing countries due to high cost of replacement of cheaper GI piping frequently.

regards,

sam
Posted by: whm

Re: ambient temp stainless steel piping on carbon steel structure - is teflon necessary ? - 08/29/05 07:15 PM

I have the same problem: the pipe is stainless steel and the temperature is 185

Centigrade(natural gas piping),there are many carbon steel anchors on the piping,no

isolator can be put between the stainless steel and carbon steel because they are

welded together, then anchors are fixed on embedding on the surface of concrete.

If there are no isolators, what will happen
in the future?Does code require this?Are there any other measures to make up.

I am worrying about if the pipe will be corroded
because of this factor.

Thank u!
Posted by: John C. Luf

Re: ambient temp stainless steel piping on carbon steel structure - is teflon necessary ? - 08/29/05 08:22 PM

the code? which code?

B31.3 gives you advice to think about this sort of thing but does not give a how to do.... thats up to you the designer to figure out.

185 C is far too hot for zip ties and rubber gasketing so heres a hint... go look at some pipe support vendors catalogs readily available on the world wide web.
Posted by: whm

Re: ambient temp stainless steel piping on carbon steel structure - is teflon necessary ? - 08/29/05 09:31 PM

Thank u for ur comments!
and i will try to fully understand the problem
as well as this kind of erosion, then deside if
it really need to modify the design of those supports.

thank u again!

i don't kown if you can give me your e-mail ,i want to ask u a question about how to use
"snubber" in static analysis in CaesarII,and
mail the CII file to you.
relative article is your June 27, 2001 article in this forum.
because i met a problem when using ur method though it's ok in some other case.
Posted by: John C. Luf

Re: ambient temp stainless steel piping on carbon steel structure - is teflon necessary ? - 08/29/05 09:58 PM

ask Richard Ay for it...

Rich please go ahead and pass along my home email adress....