Replacing Radiator Valves - Advice Sought

[Archimedes]

I'm planning to replace several radiators. The rads throughout are connected to the system via 8 mm microbore piping, so can I get away with reusing the existing olives and valve cap nuts and simply reconnect these to new replacement valves?

If this isn't a good idea, what's the best way to remove the olives from the microbore pipe tails? Is there a special tool for doing this or do they just need to be cut off (carefully) with a Junior hacksaw?

Lastly, can new olives and cap nuts be fitted without the need to reduce the length of the pipe (by having to cut off the pipe where the old olive was located)?

Any advice would be very much appreciated. Thanks.

 

[ollski]

Depends which valves you use, some may take the existing nut and olive and some won't....ask your plumbers merchant. I always cut them off and use a straight coupler to add a new bit of microbore up to the valve.

 

[Archimedes]

Many thanks for that Ollski.

Do you suggest using soldered or compression joints for the straight couplers? I've got 7 rads to do, BTW.

 

[ollski]

soldered definitely if you are comfortable with it...compressions look ugly especially in that small size

 

[Slogger]

there is a tool for cutting off olives i used one a few times ( mates ) it worked fine on 15 mm but sometimes when u cut them off u can see a groove in the pipe ( deep ) where the last fitter tightened the olive too hard so cutting the pipe off would be more professional and solder the extra needed to do job while your at replacing them valves make sure u put in a bleed off valve downstairs if there isnt one

 

[kevplumb]

there is a tool for cutting off olives i used one a few times ( mates ) it worked fine on 15 mm but sometimes when u cut them off u can see a groove in the pipe ( deep ) where the last fitter tightened the olive too hard so cutting the pipe off would be more professional and solder the extra needed to do job while your at replacing them valves make sure u put in a bleed off valve downstairs if there isnt one

i take it you mean a drain off slogger ?

 

[PEDANTICVINDICTIVEMAN]

I normally manage to carefully cut through the olive at a 45 deg angle and not groove the pipe, then just put new nut and olive on using jointing paste on the pipe before sliding the cone on, very rarely had any problems as long as the old nuts and olives wern't tightened up by arnie snegger with a pair of 48" stilsons

 

[Archimedes]

Thanks for all your help chaps.

Ollski. I don't have problem with soldered joints - I'm just hoping I can dry out the pipe tails sufficiently to allow soldering. Hopefully, I'll be able to avoid this if I can get the olives off without a fuss and just slip on new ones.

Slogger. All the downstairs rad valves have nasty screw-off all-or-nothing drain caps (so typical of Bovis Homes' shoddy construction) which are guaranteed to make a mess. I'm planning to replace the valves with ones that incorporate decent draincocks which will permit a hose to be connected for draining down or back filling.

A.