Do Modern Steel Pipes Corrode Faster Than Older Ones? How to Prevent?

Ptak3124 wrote:

However, steel installation is not suitable everywhere.
If it is possible to do this, at least partially, I recommend it. But if someone wants to hide it all under screeds, I advise against it.

Can you expand on this thought about pipes and screeds? It so happens that I also intend to install the entire boiler room installation, steel manifolds, PEX for radiators and underfloor heating. Therefore, some of the pipes will be hidden in the layer of polystyrene under the screed.

p1024 wrote:

@Ptak3124
In my opinion, the water admittance valve is OK, but to disconnect it I would have to disconnect the entire house using the valve at the meter. This valve works normally, there is no flow, no sign of external corrosion, as soon as I turn it a little there is a hissing sound throughout the house.

However, I was wrong, I have already replaced the water intake valve a few weeks ago and the problem has completely disappeared. The simplest possible solution was the right one in this case.

You definitely have screw connections at the coil valves. Unscrew them and you will soon know whether the coil is tight and whether the valves are tight. Filling the system - what is worth doing? It shouldn`t be rigid. The correct way to do it is to have two valves, one from every water supply. You connect them with a hose that is normally removed from one valve. Then there is no possibility for water to flow through the leaky valve into the central heating system


And as for the main topic, I will say that I have already dismantled the systems from before the war and the pipes were clean. No corrosion or scale. Pouring some special water or inhibitors into the central heating according to I don`t think it`s necessary because rust can`t form and there`s almost nothing there, because how many times do you refill such systems in your entire life? Several times? Even if there were a dozen of them, there is almost nothing left of this stone. I don`t know about today, but about 20 years ago there were good steel pipes and there are still no problems with them. I`m talking about the systems I welded myself.