IMM wrote:
"Richard Geyman" wrote in message
...


Further to my successful attempts to remove the brass valves in my old

cast

iron rads, I have been unsuccessful in removing the iron bushes these

valves

were mounted in. Now I'm having a bit of a dilemma;

I can keep trying to get the iron bushes out, using more leverage and

heat,

but seeing as the rads are about 80 years old I'm thinking they're going

to

be well and truly seized. I don't want to break the rads getting them

out.

I can fit bushes within bushes to bring the inlet down to 1/2", ready to
take a standard valve,


To remove the bushes try soaking around them with 3 in 1 oil and leave
overnight. This will (may) work its way into the threads and ease
extraction. Otherwise heat the rad around the bush not the bush itself the
rads iron will expand and ease extraction.


but the rads are currently plumbed for gravity feed -
ie connections top and bottom at one end. Is it possible to plumb them in
to a ring in this manner, or will the efficiency be affected? If so by

how

much?


It is actually better with flow top, return bottom, gravity or pumped.



Why? Surely it would be better with flow bottom and return top to get
even temperature across the rad

Nick Brooks