Radiator connection, no taper

[Nigel R]

Hi everyone. I'm fitting a CH towel rail, with an elbow angle adapter to take an electric element as well as the water. There's no taper on the thread, so the adapter screws in until the thread ends. At that point, the pipe connection is pointing out into the room, which is no good of course. So, I've used a lot of PTFE tape and left it not actually tight. It wound in with a smooth resistance, but now as I fit the pipework it does swivel, if I push.

What do you think? Will it seal like this under 1.5 bar of pressure, or is it doomed and I need to find a better way? Any expert advice would be greatly appreciated!

 

[terryplumb]

You may not have put enough turns of PTFE on the threads ,it should feel a little tight when screwing the fitting in ,rather than " smooth resistance" as you put it.
A smear of LSX on the thread should ensure its leak free.

 

[Nigel R]

Thanks Terry. I have some LSX so I'll dismantle and add some of that and more PTFE. Appreciated

 

[Jackrae]

I've just gone through a similar exercise fitting a heater-T to a new towel rail. Despite internet searches I could not find a tecnically sound engineering solution. What I ended up doing was to get hold of a cheap stop valve such as shown. The valve was throw away but the taperd end complete with nut (let's call it the tail-piece) was fitted to the radiator. Then, in brass, I turned up an interface piece which connected to the mating face of the tail-piece on one end and had a 1/2BSP paralled male thread on the other end to connect to the T. The combination of the tail-piece and the interface unit permitted the T-piece to be orientated to suit my plumbing without the use of PTFE tape. Attached is a photo of the unit once fitted with some aluminium tape wrapped around to give a semblence of chrome.

Sealing of the taper on the tail-pice to the radiator is achieved by smearing Atmos-Pate onto the threads before mating. Similarly sealing the thermostatic valve attachment spigot fitted to the T pice was also achieved using Atmos-Pate. I have used this product on numerous taper installations, never had a failure and once it has set (give it 24hours) it will not come loose in normal operation. It's rated up to 100degC and is intended as a porcelain repair medium !

Sealing on either end of the interface piece is accomplished via the in-built 0-rings on both T and tail-piece. The heating element also had it's own sealing o-ring

Of course the plumbing purists will condem it as a "botch-up" but unless they can come up with a properly engineered alternative then my properly engineered solution is, in my chartered engineering eyes at least, perfect.

If it doesn't already exist the design is copyright to me. © 2022

 

[Nigel R]

Thanks so much Jackrae for that comprehensive solution. The adapter is not properly engineered is it! I'll have a look through my box of bits, check out Atmos-Pate and see if I can infringe your copyright . If not I'll give the LSX a go and hold this in reserve as the ultimate solution. At least I can drain the towel rail on its own, if I need Plan B.

 

[opps]

I am not a plumber, but I thought that LSX was only suitable for joins that are not under constant pressure. I have however found loctite 55 to be invaluable over the years.

LOCTITE 55

Thread Sealing Cord - immediate full pressure sealing. Allows reliable re-adjustments.

www.henkel-adhesives.com

It is like a cross between dental floss and PTFE. You wrap it randomly around the thread. They recommend that you scuff the threads (so that the product grips), but I have never had the guts to do that.

 

[Nigel R]

I have some of that thread too opps, thanks for reminding me about it. My idea about LSX is that it's a jointing compound and sealant, that would be fine internally but can be slapped on externally if you're stuck, which might be when the constant pressure issue kicks in, but I'll double check

 

[opps]

I have some of that thread too opps, thanks for reminding me about it. My idea about LSX is that it's a jointing compound and sealant, that would be fine internally but can be slapped on externally if you're stuck, which might be when the constant pressure issue kicks in, but I'll double check

I may have been wrong about it only being suitable on joins that are not under pressure. That said, they recommend eliminating the pressure until the silicone has cured.

 

[Nigel R]

Thanks opps yes good point about letting it go off, that is what I'll do . I've added some more PTFE and lsx and it's about as tight as it can be so fingers crossed

 

[opps]

Thanks opps yes good point about letting it go off, that is what I'll do . I've added some more PTFE and lsx and it's about as tight as it can be so fingers crossed

From memory, Ls-X goes off faster when water is used as a catalyst to speed up the curing. Best of luck.

 

[cross thread]

Liquid thread seal from screwfix etc .just let it set a per the instructions