Pipe insulation and jacket in very humid environment

[VoDich]

I am looking to put insulation and jacket on chilled water piping (2 to 6 inches diameter), ductwork (30" diameter), and equipment (pumps, air handlers) located outdoors near coastal environment of Hawaii. I need help with selecting the right materials. My main goal are effectiveness and longevity. If one is not much better than the other, then I'll go with the cheaper one. My choices are:

Insulation
1) flexible elastomeric. I heard that this will soak up water and deteriorate over time, even with jacket. Not sure if this is true.
2) cellular glass

Jacket
1) 0.016" thick, 316 stainless steel
2) 0.016" thick, aluminum. I heard that aluminum jacket in Hawaii is less prone to corrosion than stainless steel. Again, not sure if this is true.

Suction Diffuser for Pumps
1) iron body
2) bronze

Thank you in advance.

 

[chicopee]

Look up at the type of insulation used for building foundations. I believe that it is a polystyrene so double check. It is a closed cell rigid foam. Normally it comes into sheets however it may be made into cylindrical shape. The main concern is the UV light from the sun so double check about its resistance to UV.. Being closed makes it impervious to water. Owen corning is one manufacturer.

 

[nuuvox000]

A quick search seems to suggest that stainless steel fairs much better in marine environments than aluminum. If the jacketing is sealed, then it may not matter what kind of insulation you have inside.

https://www.assda.asn.au/43-applica...nce depends,is highly resistant to corrosion.

 

[gerhardl]

I suggest that you google references/suppliers fro offshore North Sea and Norway/Scotland, which have similar (but much worse) climatic conditions.

Two main methods: self adhering waterproof material, or water sealing material plus isolation material in the middle and water sealing material as outer cover.

 

[gerhardl]

Why do you need jacketing? Good isolation might be much cheaper in cost and give less maintenance.

 

[VoDich]

Thank you for all the suggestions.

nuuvox000: Thanks. The subcontractor might be trying to substitute stainless steel with the cheaper aluminum.

gerhardl: I wanted jacket as a layer of protection so the insulation won't get deteriorated as fast.