Rad valve extensions (fixed type) Sealing?

[superstardeejay]

I've fitted a few of these as I've progressively replaced radiators in my house. So far I've used PTFE tape into the radiator and then PTFE from the valve into the extension. Although the valve tail is a taper thread, the one on the radiator end of the extention appears parallel, and I've had problems getting enough tape on there to make a decent seal. It's got me thnking...should these come with an o-ring instead, like a modern bleed valve does?

 

[Steelmasons]

I bet they look great...proper job..

 

[Jackrae]

If the thread is parallel then yes, there should be a sealing ring of some sort. Alternatively, if the fitting isn't too rattly a fit into the rdiator end you could use a self setting joint sealing liquid such as http://www.loctite.co.uk/thread-sealing-9170.htm

 

[superstardeejay]

I bet they look great...proper job..

Not sure if that's an endorsement?

Extensions like this are great when you're going from an imperial to metric radiator as I am; in this case from a 50 inch to a 1200m. The pipes are set into the concrete floor so moving them in or out by an inch or two would mean pulling up the fitted carpets, ripping a portion of marley tile out and digging up the floor. The other options would be raising the radiator and pipes with a slight s-bend or fitting an undersized radiator with elbows and straight valves. Either way that's untidy.
I've heard tales about leaking telescopic extensions that rely on a sliding seal. These are a more solid fitting.

 

[Agile]

I always extend or reduce the width using elbows on the copper tails from the floor.

The sliding extensions look and feel pretty flimsy. But I have never had any problem when I have used them.

Tony

 

[DP]

A pipe bender anyone?

Suppose all that plastic does not need a pipe strangler

 

[superstardeejay]

A pipe bender anyone?

Suppose all that plastic does not need a pipe strangler

??
No plastic on my radiators.

I don't think there's room to get elbows on the pipe stubs coming out of the floor, as the radiators are only about 40mm short each side. I could mount the radiator to one side and just use one dog-legged pipe but I think this would look a bodge. At least the chrome extensions look neat.

 

[rules&rulers]

stelrad radiator extensions. Have an o ring to help seal that join.

 

[Agile]

Street elbows sometimes come onto their own for these jobs!

 

[superstardeejay]

I did think about a couple of those but the rads are so close to the floor that I dont think I'd get them in unless I cut the pipe so close to the floor that I'd risk burning the carpet when soldering.

 

[Steelmasons]

I did think about a couple of those but the rads are so close to the floor that I dont think I'd get them in unless I cut the pipe so close to the floor that I'd risk burning the carpet when soldering.

Burning the carpet???..pull it back in that case..
If you can solder then why not @ least alter the pipework upstairs unless solid floors too?....
If you can solder then surely you would alter pipework to suit replacement radiator whether solid floor or not...

 

[Steelmasons]

Street elbows sometimes come onto their own for these jobs!

I'd rather see extension pieces in that case....or do the job properly and alter pipework to suit...
We've got 28 cast iron column radiators to fit.....existing radiators being barlo....we can either cobble a couple of 15mm elbows together in order to suit new radiator valves or possibly cut pipework under the floor and come through floor nice and straight into radiator valves..........not sure which would be the better option?...the latter will cost more money so will possibly opt for the former.........the radiators are finished in a stove enamelled pewter and look stunning.....tis a shame the pipework is gonna look absolute shyte.....must remember to pick up 56 22x15mm reducers as the radiator valves supplied are 3/4"....hopefully there's enough space between valve and finished floor level to enable the reducers to fit....gonna look the nuts...

 

[PullerGas]

I have never used extenders, chrome Oyster fittings is what you want & a piece of chrome 15mm pipe.
Cheap as chips & a lovely job!! Of course you'd alter pipes under a floor where ever poss.

 

[superstardeejay]

No I'm not going to dig up the floor. I have a very expensive fitted carpet and marley tiles under that. The floors are concrete. If the pipe ends up coming through the carpet in a different place there will be a hole where the old pipe came out.
My question wasn't about the various ways of fitting a different sized radiator. It was how to properly seal the tail extensions into the radiator. I've ordered some of the loctite threaded pipe seal as recommended by Jackrae. The extensions dont have a rebate to accomodate an o-ring so unless I lathe a recess, I doubt one would work unlike those stelrad ones that seem to work like a bleed valve. I suspect if I used an o ring on these it would just squash or stretch out of the way as there's nothing to keep it in place.

 

[Steelmasons]

Loctite 55 is your best friend (string)..