Fitting radiator vales to the radiators, help please

plumb1_2

have found the internal threads on most towel rads are some what larger by 1000th of mm etc. The rad tails are always slack. Need loads of ptfe and paste. Cheapo inports. If i get a leak on a rad 99% its the towel rail:mad:

Even the air vents are slack. Someone tell those chinese to use 1/2" bsp threads:D

southcoastrgi

Plumbers_Shop_Lee wrote: »

To answer the op's original question the radiator tail is slightly tapered from back to front so that as it is screwed in it will naturally come to a stop, as others have suggested tho always use thread seal tape/jointing compound on these threads.

really !!

the thread inside a towel rail is parallel not tapered, therefore the rad valve tail is parallel as well you can't just use one thread on another, you use loads of ptfe because as you screw it in it pushes back & forms a washer, loctite 55 works slightly differently, jointing compound won't work & it will leak.

I'm glad i don't ask for advice in your shop

OP you will find you will have about 3 or 4 threads still showing, if you have any less you haven't put enough tape on.

Plumbers_Shop_Lee

Southcoast, I don't recall saying anything about the thread in a towel rail at all? I merely pointed out that the tail of a trv 4 is tapered nor did I say to use jointing compound in isolation!! So if you wish to pull me up and make snide remarks read what I've written first there's a good boy!!

Jonesya

If you've not bought your consumables yet, you might want to try gas spec PTFE tape, only slightly dearer than standard PTFE tape but much, much thicker than the standard film-thin stuff.

southcoastrgi

Plumbers_Shop_Lee wrote: »

To answer the op's original question the radiator tail is slightly tapered from back to front so that as it is screwed in it will naturally come to a stop, as others have suggested tho always use thread seal tape/jointing compound on these threads.

Plumbers_Shop_Lee wrote: »

Southcoast, I don't recall saying anything about the thread in a towel rail at all? I merely pointed out that the tail of a trv 4 is tapered nor did I say to use jointing compound in isolation!! So if you wish to pull me up and make snide remarks read what I've written first there's a good boy!!

no they aren't, if they were you could use jointing compound to seal them, but you can't, I've read what you've written but I'm not sure you can old chap

Plumbers_Shop_Lee

Did you run out of blue highlighter just the other side of that slash? And I maintain a tail for a TRV4 is tapered otherwise the tail if used dry would disappear inside the rail much like a hex nut on M10 rod which will run freely up and down because both are parallel

southcoastrgi

Plumbers_Shop_Lee wrote: »

Did you run out of blue highlighter just the other side of that slash? And I maintain a tail for a TRV4 is tapered otherwise the tail if used dry would disappear inside the rail much like a hex nut on M10 rod which will run freely up and down because both are parallel

no I just thought you might prefer a diff colour

& if it was tapered you would split the connection on the rad, there is a reason that the plug & bleed nipple on a towel rail or rad are sealed with an "O" ring, the same as some rad valve tails are sealed with an "O" ring

Plumbers_Shop_Lee

We shall have to agree to disagree on this one, however next time you are in your merchant have a look at the instructions and diagram on a TRV4 which advocate the use of jointing compound (not in isolation admittedly) & show the tail as being tapered.