Replacing thermal insulation in a sweating chilled water pipe 1

[MedicineEng]

Hi all:

In our property I recently discovered some sections of insulation on our chilled water pipe destroyed due to mechanical damage and these need to be replaced.

The problem that I have is that this chilled water pipe feeds some critical areas of our property and it will be a real nightmare to stop the supply, warm up the leg to not sweat and then replace the insulation.

Does anybody know of an insulation product that can be applied in a sweating chilled water pipe?
I know that this goes against all the traditional way to insulate chilled water pipes, but maybe there is a new product in the market that I'm not aware of that can address this type of situations.

Thanks a lot.

 

[EnergyProfessional]

You could de-humidfy the area to prevent condensation on cold chiller pipe? not sure there is a dehumdifier for low enough dew point, though.
i bet the old insulation is fiberglass with some "vapor barrier". Use some inherent vapor-tight product (some foam product)

 

[LittleInch]

Solid PU foam or Foam Glas. What diam and length?

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[MedicineEng]

The insulation would be working fine if somewhere in the past we didn't have a contractor stepping on it, as I suspect it happened.
Dehumidifying the space is not possible since it is a huge open area above our commercial space.
I was hoping that some genius already had developed a thermal insulation that could be applied in a sweating chilled water pipe without detrimental effect, but I guess that I have to go the traditional way and wait for the backlash from stakeholders...

 

[LittleInch]

What's wrong with PU foam or Foam Glas? Neither are affected by water standing on the pipe.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[EnergyProfessional]

LittleInch: foam glass is no vapor barrier. Sure they say they out a mastic sleeves around it, but that is not sufficient and easily gets damaged.
you need to use special low-perm foam insulation. Even if someone cuts in it, or doesn't apply 100% correct, it is inherently low-perm.
Yes that is more expensive, but that is the case with quality most of the time.

 

[LittleInch]

What's a vapour barrier got to do with it? what do you use now?

They are not perfect, but if you cover them with suitable external sleeves or wrapping then you are still much better off than a rock wool type material which is wet and then doesn't perform?



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[lukaiENG]

You could apply heat to the section of piping being insulated to warm the pipe surface up? maybe some infrared? might not work for your environment - just spit balling.

 

[DrRTU]

Look into Armacell. It is a little high on $/ft but simple to install when the piping is wet.

http://www.armacell.us/home/