pipes into the rad

[ifIhadahamma]

i want to replace a single rad with a double without draining the system and replacing the valve and lockshield. The trouble is the rad i bought has no pipes to join it to the valves and the existing ones on the old single are a bit manky D).. can you buy new pipes or do I have to extract the old ones (which don\\\'t have a nut on??)

 

[bathjobby]

the rad i bought has no pipes to join it to the valves

What does that mean ? Radiators come with threaded holes into which the valves are fitted and obviously the valves are connected to the pipes.

 

[ifIhadahamma]

yes, it has the threaded holes but not the pipes (which you're saying are part of the valve?).. can you buy new pipes to fit the existing valves? I assume it's all standard stuff? I don't want to have to get the old pipes off the single rad and I assume they have an internal hex or something as there's only the nut for the valve end (smooth pipe going into the old rad..)

sorry if i'm explaining myself poorly

 

[bathjobby]

Yes, it is a struggle, but I think I see your question. When you say 'no pipes', you mean the piece that fits into the rad between the valve and the rad ?
When you undo the large nut on the valve and pull the valve away from the rad, the threaded part that the valve was screwed onto and which is fitted into the rad can be removed from the rad (surprise, surprise) with a radiator spanner. It is basically a box shaped end which (as you said) fits inside the connector allowing you to turn it. Yes these are all standard parts and available in most diy sheds. Just make sure you know your pipe size when buying new valves, 15mm, 10mm or even 8mm.

 

[ChrisR]

But he won't be buying new valves to fit the actual, vertical, copper, 8/10/15mm pipes, only for the part which goes into the rad.

There are two sizes for the union between the rad valve and the radiator piece, 3/4" sbp and 1/2" bsp. Most non-thermostatic valves are 3/4". (Nut is about 1 1/4" across).

If you buy a cheap valve you can just use the part you need, but because it wasn't designed to fit that particular other half, you may need something to stop it leaking, like several turns of ptfe or sealer like fernox LS-X. Don't put either on the threads of the union - they won't even be wet. Put plenty of ptfe on the rad fitting end though.

 

[bathjobby]

Hey ChrisR, it was a struggle enough to understand the point without guessing what he may buy, LOL.

 

[ifIhadahamma]

thanks for the help guys.. i bought two cheapo 15mm valves and a radiator valve allen key/box key. Hopefully I'll be able to use the two rad connectors off these valves and not have to replace the existing valves (don't wanna have to drain the system).

interestingly when I asked the bloke in B&Q if this allen key was the right size to screw the valve parts into the rad he said 'no, use grips'.

ahem.

 

[Soggy_weetabix]

Am I missing something but you wanting to replace valves without draining?

A good bung kit will help, as will a frezer kit.

If not (and this is a joke)....sheet on the floor, sheet over your head, and JUMP IT LIVE. Be quick!

Only for the confident though.

(Did a gasket change on a bbu with bungs. Hairy but it was done in an hour and a half)

David