Hurray, it happened, "civilization" has reached our yard. They began to change pipes for heating and hot water supply. And then the whole yard was plowed in search of gusts of hot water, in recent years. There was practically no living space (asphalt) in the yard, everywhere there was dirt and dust. But this came to an end. They will change pipes and lay asphalt, probably)))
The tractor driver dug up the entire yard, simultaneously collecting copper wires and black metal crawling out from under the bucket. He has a good job, but also responsible. Every now and then there were cables under voltage.
We started to import the pipe, I was surprised by one moment: Is it possible that a black plastic pipe will withstand the temperature and pressure of the heating system?
But after looking closely, it became clear. That black pipe is a shell. Inside there is an iron, insulated with a layer of polyurethane foam, resembling foam from cans.
The sandwich structure of the pipe is visible in these scraps. Polyethylene, foam and iron pipe. Good insulation by itself. I think that the heat loss is much less than manual insulation with glass wool.
But the most interesting thing is for me. I'm a plumber. What kind of wires are sticking out of the pipes.
Some are even copper.
I decided on this matter to turn to the welder who installed this know-how of the pipe. In the end, he told me this:
After installing the pipeline in working condition, these wires serve as rupture sensors. When the layer of insulation in which the wires are moistened, their resistance changes. Which is easily calculated with special equipment. Thus, it is possible to find out in which section of the pipeline the outer shell or the pipe carrying the heat carrier is damaged. Therefore, it is easy to calculate where it is necessary to remove the soil layer for repair, without unnecessary digging of the entire neighborhood.
Such a new technology, telemetry, has reached ordinary yards.