Posted by jtown on September 17, 2001 at 06:35:17:
In Reply to: Research question posted by JonDeEsch on September 13, 2001 at 15:57:03:
"the radiator reacts by expanding and contracting"
The radiators don't expand and contract, nor does liquid water to any extent. The gas (steam) inside will with a change in temperature or volume, including a huge difference in changing state from liquid-vapor. "jacking up the radiator on the drain end so the water can flow out easily."
You normally jack up the end away from the one-pipe inlet/outlet. Just bring them up level or slightly above or you can get rust deposits to slide over to the valve.