HOT RADIATOR HOSE IN CONCRETE?

[STRCIVIL]

I want to run four 6" remote radiator line 3' deep in ground. My mechnical engineer is saying that the pipe temp. will go up to 250 DEGREES (F) and will expand 1" every 10'. I am running approximately 80' of this pipe. Does anybody have any recommendations or experience on this type of construction? Please give me some hints on what type of materials to be used for encasing these kind of pipes underground...concrete...insulations. If possible, what type of insulation should be used....
I would really appreciate it!!!

 

[ishvaaag]

Browse searches like this...

http://www.google.com/search?q=insulation+buried+pipe+hot+water&hl=es&btnG=B%FAsqueda+en+Google&lr=

and good luck!

 

[austim]

Hi, sircivil.

If your radiator pipe is to be manufactured from steel, then I suggest that you go back to your mechanical engineer, and ask him to confirm his figure of 1 inch per 10 feet at 250 degrees F. (or better still, calculate it for yourself ).

Assuming that it WILL be steel, then the accepted coefficient of thermal expansion is 0.0000065 per degree F.

If we assume that the pipe will be installed at only 10 degrees F, then you would get 0.0000065*120*(250-10) = 0.19 inches expansion per 10 feet, or 1.5 inches per 80 feet.

 

[pigdog]

sir,
You mention isulation but also call this radiator pipe. Is this a ground loop for a heating/cooling system? You may need a ground loop and a heat exchanger. The ground loop would run a lower temp and be filled with non corrosive fluid. Whatever you are cooling is above ground where you have access.
roger

 

[Ron]

STRCIVIL...as austim pointed out, your mechanical engineer needs to re-visit his calcs! That much movement would rip just about anything apart! Think about results that are given to you and see if they seem practicable. One inch of movement in 10 feet borders on absurd (assuming steel!). If you indeed have a material with expansion properties such as indicated, pick another material!!

As for insulation, there are numerous ways to insulate the pipe from "soft wrapping" with soft insulation to using rigid insulation. Further, you can isolate the movement with a flexible connection at either end of the pipe run.

Plan ahead for potential repairs. If you encase in concrete, it will be difficult to pull and repair the line in the event of a leak. If you create a mechanical "chase" from concrete, you will then be able to insulate the pipe and access the pipe for inevitable future repairs.