Underground and submerged lines insulation and heat tracing.

[curtis2004]

Hi everyone,

1. I have water and condensate drain CS lines going U/G which shall be insulated and heat traced to the portion above frost line. Is there any guidelines what materials to use for insulation cladding and heat tracing?

2. I have a concrete storm water basin with submerged water pump in the bottom, which will pump water away. Water lines is changing and may freeze in winter if not pumped out entirely. Is there anything shall be done in order to protect pump and vertical CS pipe line from freezing? My first thought was to protect it from freezing by insulating and heat tracing both pump and line. However, now I am more inclined that maybe small heater inside pipe may suffice. Did anyone had similar project with pumping out water from open pond?

Thanks,
Curtis

 

[PEDARRIN2]

For insulation on the piping, I typically use cell glass, although closed cell elastomeric works as well.

For heat tracing, I typically use Raychem (owned by Pentair). They have a nice online sizing program that gives you design guidance, as well as electrical requirements, bill of materials. I have used it on several projects.

 

[curtis2004]

PEDARRIN2,

What kind of jacketing material is used with cell glass insulation material? Any other sealing or caulking?

Thanks,
Curtis

 

[PEDARRIN2]

The specification I use: Foamglas insulation shall be Pittsburgh Corning “Foamglas” molded pipe insulation. Fittings shall be insulated with machined segments of pipe insulation or block or board stock. Joints shall be sealed with vapor sealing adhesive, complying with the specification of the insulation manufacturer. Jacketing shall be 70 mil self-sealing modified bituminous membrane “Pittwrap SS”.

 

[LittleInch]

What ever you use needs to be as water tight as you can get.

Agree with pedarrin - cellular glass (foamglas) is good, usually with a thin outer wrap to give you the water tightness between the joints. Talk to Foamglas and they will advise / give costs.

Pre made PU foam is pretty good as well and used a lot in heating / cold water systems in cities. Jointing the outer PE jacket can be fun, but there are systems which work.

Depends what you're doing with the heat trace, how long and how big your pipe is, but self limiting tape is probably your best bet, but depends if you're trying to keep it hot or just not freeze

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

 

[bimr]

Most people use fiberglass insulation for the proposed application. Foamglas is more expensive and is generally used with flammable liquids. The insulation jacket and be aluminum or pvc.

Self limiting heat tape is also used.

 

[PEDARRIN2]

My experience is limited to kitchen waste (grease) drainage piping going to an exterior grease interceptor.

My thoughts about fiberglass in this type of installation, though, is the jacketing and vapor barrier had better be perfect, because the smallest crack is going to let in moisture/water which will accumulate and when fiberglass gets wet, it is worthless.

Also the foamglas is more robust and will not compress with the weight of backfill on top of it.

If the cost of foamglas was an issue, I would use the closed cell elastomeric insulation. It is not affected if it gets wet.

 

[bimr]

I believe that most of the piping the poster is referring to is above grade. See "portion above frost line".

However, the text in the post is somewhat confusing.

If the piping is submerged, you would have to use the closed cell elastomeric.

 

[curtis2004]

Binr,

Yes, you are correct. I have different lines and systems. Most of the lines are A/G. Just few drain lines go U/G.
I have a separate storm water system line starting from a pump in the bottom of a storm water basin, which will be submerged, since water elevation will be changing within min and max levels.
Those are important cralifications.

Regards,
Curtis