Plumbers-mate

[DarrenSL]

Help! I am in the process of fitting a (dual fuel) chrome towel radiator in the bathroom and have hit a snag. The T-piece (for the electric element) screws in such a way that when tight the side arm (for the rad valve) points outwards rather than to the side. There is no way to avoid this as the t-piece is simply a thread with a rubber o-seal. It feels pretty loose when left pointing to the side and I'm convinced that under pressure the system will leak. As a fix I was planning to smear the thread with plumbers mate. Wise

 

[Al-Glasgow]

Cant you use PTFE tape ?.

Al

 

[Kes]

Hi,

I wouldn't use Plumbers Mate or any gunge-type stuff. I guess the threads are parallel. Use ptfe tape on the threads (keep the rubber seal) and tighten so that it's in the right position just before it gets to the wrong position (well, I know what I mean). If you think it's still too lose then remove and reapply a little more tape, but remember you're sealing a thread not bandaging a broken limb.

Rgds.

 

[DarrenSL]

Thanks very much guys. I'll give it a go!

 

[Nige F]

Hemp+ Boss white

 

[garethgas]

I doubt very much if the threads will be parallel. But would agree with either PTFE tape or even hemp.
Garethgas

 

[Kes]

Hi,

I don't know the mechanics of the thing but anything that tightens up onto a neoprene (or whatever material it is) seal probably has parallel threads, otherwise the thread could tighten before the seal has er, sealed. But it doesn't make a great deal of difference to the solution!

Rgds.

 

[JohnD]

What about a washer under the head, so it screws down tight without going in so far?

 

[DarrenSL]

To be honest I don't know what you mean by parallel threads?? It has a clockwise thread and I screw the T-piece directly into it up to the point where the o-ring squashes and the joint is tight.

Either way, ptfe worked a treat. I didn't realise that such a simple fix was all that was required. It needed a good 15 or so layers but feels reasonably tight and doesn't leak even when hot and under 1.5bar pressure.

Thanks for the tips.

 

[Kes]

Hi,

Male and female threads on boilers, pipes, radiators and associated brass fittings are (in general) slightly tapered, so that they tighten as the two are screwed together. These can only be screwed together for a certain distance until they are tight, and take some form of thread sealant such as ptfe tape or the old Boss White and hemp. It's the thread that's sealed.

Male and female threads on taps, wastes and traps, ball valves etc are parallel. If you screwed one on to the other it would just go on for ever unless there was a flange to stop it (just look at the way a trap seals to a waste, or a tap connector to a tap). These are intended to be sealed by a washer or similar on the mating surfaces. The thread isn't sealed.

I thought your fitting would be parallel as it has a rubber sealing ring, so presumably the fitting screws into the thread until the seal is trapped.

Well, it's another success with good old ptfe tape, so all's well that ends well.

Rgds.