twin entry valve

I am buying a flat at the moment and all the radiators have just one inlet where the 2 pipes enter. Is this a twin entry valve? Ideally I would like to renew the radiators so would like to know if I can swap them for new radiators and re route the pipes to either side with standard inlet and...

I have to fix a radiator or towel rail radiator in a bathroom as the radiator is missing. The old connection has been left with only a twin entry valve. Can I install a normal double radiator ( 40 cm width) by connecting one end with the Twin entry valve and cap off the other side of the...