insertion tube and return screw

[Achilles]

I am trying to replace a radiator after decorating. It is a microbore system with a return valve and pipe. The insertion tube became loose and I had to shorten it at the return end. I then pushed the tube back but it seemed loose. In addition when I did replace the radiator the return screw would not tighten. Are the two problems related? Do I need a new insertion tube?

 

[leakydave]

Pic? I dont know what an insertion tube is...

 

[GasMan1965]

I think he means a double rad valve where flow and return both in the same side ,,,
Youll need a new double rad valve I would say !!