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[heat550]

I called to manufacturers of tape to use on insulation on 1 inch copper. Now 2 engineers told me that tape can only touch insulation.
And don't let it touch the copper because the tape will react with the copper. A third company even makes an adhesive that's a liquid that you can put between the insulation seams.  I'm putting insulation on a pipe that I got to push through 80 feet of insul seal the chances of that insulation coming off and the tape might rest against the copper so instead I'm going to use a kind of Zip Strip Velcro to hold insulation in place. Has anyone ever heard of different adhesive tapes reacting with copper. New to me.
Heat550

[slimjim]

It would not surprise me in the least heat, I have been following your journey a bit and I must say that I think you would be far better off to install a good quality manufactured underground pipe.

[wreckit87]

I second that^^^. However, it looks like you've gone too far to turn back now and can dig it back up next year if it doesn't perform as planned. As for the tape though, I guess this is news to me. Copper pipe comes right from the factory with that stranded packing tape holding the bundles together, and lots of it. I always try to burn it off for aesthetic purposes, but most do not. There are a lot of folks with a strip of regular old black electrical tape on their copper lines to check temps with an IR gun, as the copper is reflective and gives a false reading. With that said, I do a lot of commercial work with original piping dated back to the 60's and residential back to the mid 80's and the only copper failures (which are few and far between) are at or near a joint, or somewhere where the pipe is in contact with something ferrous like an iron hanger or something which causes electrolysis. I find it hard to believe that tape could be of concern. Any reason you're not running PEX instead of soft copper if you insist on building your own underground? I seem to have missed that discussion.

[heat550]

It's all going good velcro strips are going to work perfect. Just no tape is going in the insulseal with the copper. I will endup with R20 and R23 on the hot line going to house. Here is a picture of trench prep .. I call it the water shed backup under insulseal . 2 inches of sewer rock and smaller rock there 2 inch drop every 10 feet. Here's a picture.

[heat550]

The thinking behind copper is one time install. No ripping it apart changing pex Al pex incase of over heat. See copper cost close to same as 2 runs of pex Al pex runs. Well we know you over heat pex it bubbles plastic inside restrict flow without you knowing it. So ya it's over kill install I know. But will post heat loss numbers and heat output numbers . It's 1 inch K soft copper it's pretty dang tuff stuff.

Heat550

[wreckit87]

You'd never get water hot enough to bubble the PEX in an open system as it'll boil out long before that happens. I am curious to see some numbers when this is over though, way to think outside the box. Most of us just cheap out and buy the $10/ft preinsulated underground that we already know performs well and installs in minutes instead of weeks

[E Yoder]

You'd never get water hot enough to bubble the PEX in an open system as it'll boil out long before that happens. I am curious to see some numbers when this is over though, way to think outside the box. Most of us just cheap out and buy the $10/ft preinsulated underground that we already know performs well and installs in minutes instead of weeks

I agree, and I like to here about experiments like this too.  Keep posting.

[heat550]

Yes pex al pex can bubble inside even on a open system .  Look at there temp rating Its not as much as your thinking .
Will be installing insul seal soon . Then the copper . Weathers not been on our side . I have collected most of the components
but it will go in to December I still need to put boiler together yet. slowly coming along . got the frozen ground out of the way now .
wow does it freeze up fast goofy fall . 

heat550

Installing wires for a temp logger also 3- cat 5e wires going to boiler in conduit away from electric line. if you can think of any other lines
I would need I have extra 3 wire for alarm and if I want to put in a pump temp sensor to kick pump on and off at a set point as the pumps going in the house . and another 3 wire for power and outside light and plugin. Might be over kill on wire but we got them if needed . 

[wreckit87]

I assure you, neither PAP nor regular PEX will bubble at 212*. We had a customer last year running 8psi STEAM (230*) through PAP to serve an equipment sterilizer and it had been that way for "several years" according to the maintenance guy. When I cut it apart, I cut the tubing into a million pieces looking for some sort of defect and found nothing of the sort. I still can't believe nobody got hurt, but it made me a firm believer in PAP that's for sure. As far as regular PEX, I've never seen or heard of it failing either, but never seen it above 212* either. Plenty of overheated OWBs get to 212* before they burn and I do tend to check the tubing during the swap out and never saw a hint of deformity unless somebody put the torch on the tubing too long to soften it up. Even then, the deformity is on the outside. At any rate though, thanks for the update. I'm excited to see some data when you're finished!

[E Yoder]

I agree with wreckit, I don't see an open system damaging Pex or PAP. But I do find this thread interesting and don't say that to stop innovation.
The threads I've read about PAP delaminating weren't from temperature if I remember right.
To be honest, everything I've done underground is with Pex B tho.

Keep posting, I'm very curious how it works.

[heat550]

I think the delamination happens with age and heat . The tubes coming out of the ground to my boiler has signs of it and it's never
Been over 180f . And I took a car cam scope and stuffed down there
Inside was still smooth and round but outside of pex Al pex had signs of bubbling and like the outside plastic layer was bulging . So it's in a spot I can see and keep a eye on so I left it . So that was 1996 install. Who knows what it's doing in the rest of the 245 feet I have in the ground . I will try and get a picture of it . I'm thinking it's a age issue . It's seen alot of BTUs in 20 + years. Where this coming in is how many guys have pex Al pex line sets over 20 years old. 

Heat550

[heat550]

Here's a picture best I can get . But it was more noticeable when stove was removed I can try again at day light.

Heat550

[heat550]

It's about duration 252+ cord of oak went thru that line there on boiler number 2. 25,000,000 ÷ 2= 12,500,000 × 252 = ? Yes run calulater across that . And you can say why did it bubble like that
I say there is unknown issues with Pex Al Pex . So the fix is copper.
Until I prove there's issues there. 
Heat550

[E Yoder]

I can see why you're concerned.
I heard stories of PAP delaminating , some kind of electrolysis issue with the aluminum maybe?
Anyway, keep us posted!

[heat550]

Insulseal incased in sand applying rubber underground roof . Any water is directed to outsides of trench leading to under insul seal rock bed for water drainage witch is slopped 2 inch per 10ft to other end of trench by boiler witch is directed to a drain pipe to go to otherside of boiler witch is going down hill on other side of boiler.
Project 0 degree heatloss. Projects coming along.
Heat550