Heating connection valve block pipe cutter

Good day to the experts here, I have a problem with my heating system. This year I bought a house from 1979 and then learned that this house has a 1-pipe system on each floor. Now I wanted to install new radiators with valve blocks, but unfortunately the compression rings are not completely tight on the union nut. Unfortunately, I can't find a solution for steel pipe 15mm with 1.5mm wall thickness. In the picture you can see the connection. Moisture occasionally comes out at the union nut.

Hi

But the valve block is not for a single-pipe system. I would have the valve block, since it is damaged, and the compression fitting replaced. The wall thickness of the pipe is not relevant. How do you come to 1.5 mm?


Olli

I measured it with a caliper. I took this valve block because I used it for the attic in this case, where from the manifold only one pipe goes up and one goes down; the other valve blocks have regulation in the middle. The problem is just how to make it simply tight, no matter where you ask, people say there are no compression rings for metal pipes and such.

Hi

Just google [Klemmringverschraubung 15 mm]
Almost every plumber has something like that on their van.

Olli

Already done everything, unfortunately everyone is always only for copper and everyone always says there is nothing proper for metal.

Hi

These statements are incorrect.
e.g. Ofix CEP for copper, stainless steel, and precision steel tubes

Olli