Duel entry radiators

[Bronze_tap]

its twin entry valves, made life easier for piping up as both pipes come to the same end of the rad. the flow has a pipe inside the radiator which goes approx half way along and creates the flow around the radiator and returns to the valve and through the outer section of the valve. cant fit them to most new rads as the bit you put the valve tails in is usually offset.

Also this design "benefits" from the counter flow heat exchange between the flow and return via metal valve body, which helps with keeping the heat to the main system pipes, away from the rad

The person designing them probably didn't know much about the laws of thermodynamics and metals heat conductivity...

Better to pipe your rad diagonally, on opposite corners, with flow from the top, that way you rad acts as a proper counter flow water to air heat exchanger, giving most of the heat away to the room.

 

[Ermintrude]

Nice sensible post tap.

 

[stevetheplumber]

everyone is rubbishing dual entry valves but when you think most will be easily in excess of 20 years old theyve not done to bad realy the idea was to reduce pipe runs you only run to one end of each rad
if it wasnt for the change in rad designs they would be making a comeback now with the majority of new builds in london use tem mm pipes