Is the connection between a radiator tail and the actual valve any sort of standard? And/or the overall "width" of the valve?

I'm trying to work out what my chances are of swapping the existing valves for TRVs without fitting new tails and adjusting the pipework.

Since it's cold, I want, for a change, to estimate the duration of the work before I start it.

On Friday, November 8, 2019 at 10:12:17 AM UTC, wrote:
Is the connection between a radiator tail and the actual valve any sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2" because why would anyone bother setting up for anything else.

On Fri, 8 Nov 2019 02:16:35 -0800 (PST), wrote:

On Friday, November 8, 2019 at 10:12:17 AM UTC, wrote:
Is the connection between a radiator tail and the actual valve any sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2" because why would anyone bother setting up for anything else.

I think you have missed the point of the question by snipping and only
replying to one bit (missing the 'bigger picture' in the process).

It wasn't the diameter of the input pipe, it was the distance between
that pipe and the radiator, something someone replacing a std with a
complete new TRV would like to know.

Cheers, T i m

On Friday, November 8, 2019 at 11:12:09 AM UTC, T i m wrote:
On Fri, 8 Nov 2019 02:16:35 -0800 (PST), wrote:

On Friday, November 8, 2019 at 10:12:17 AM UTC, wrote:
Is the connection between a radiator tail and the actual valve any sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2" because why would anyone bother setting up for anything else.

I think you have missed the point of the question by snipping and only
replying to one bit (missing the 'bigger picture' in the process).

Not quite, because I replied to my own question!

It wasn't the diameter of the input pipe,

I was referring to the size of thread that connects the valve to the tail, and realised that surely no one would make it anything other than 3/4 or 1/2, so if it looks like a 1/2, it is a 1/2.

it was the distance between
that pipe and the radiator, something someone replacing a std with a
complete new TRV would like to know.

That question stands.

In article ,
wrote:
Is the connection between a radiator tail and the actual valve any sort
of standard? And/or the overall "width" of the valve?

I'm trying to work out what my chances are of swapping the existing
valves for TRVs without fitting new tails and adjusting the pipework.

Since it's cold, I want, for a change, to estimate the duration of the
work before I start it.


Not all makes of TRVs are the same or indeed interchangeable. So you need
to look for ones which are a direct replacement.

--
*Husbands should come with instructions

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
wrote:
On Friday, November 8, 2019 at 10:12:17 AM UTC, wrote:
Is the connection between a radiator tail and the actual valve any
sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2"
because why would anyone bother setting up for anything else.

You've rather obviously never done this job. The centres of the pipe and
rad can be different between a LSV and TRV, as can the length of the pipe.
Even the type of olive used different.

--
*I have never hated a man enough to give his diamonds back.

Dave Plowman London SW
To e-mail, change noise into sound.

On Fri, 8 Nov 2019 03:18:08 -0800 (PST), wrote:

On Friday, November 8, 2019 at 11:12:09 AM UTC, T i m wrote:
On Fri, 8 Nov 2019 02:16:35 -0800 (PST), wrote:

On Friday, November 8, 2019 at 10:12:17 AM UTC, wrote:
Is the connection between a radiator tail and the actual valve any sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2" because why would anyone bother setting up for anything else.

I think you have missed the point of the question by snipping and only
replying to one bit (missing the 'bigger picture' in the process).

Not quite, because I replied to my own question!

Doh! ;-)

It wasn't the diameter of the input pipe,

I was referring to the size of thread that connects the valve to the tail, and realised that surely no one would make it anything other than 3/4 or 1/2, so if it looks like a 1/2, it is a 1/2.

Well, I'm not sure you can even assume they will be interchangeable,
even if they are nominally the same size / type of fitting.

I say that because I have gone to replace say a gate valve and hoped
to retain the existing nuts / olives, only to find the thread a
different pitch / tightness?

it was the distance between
that pipe and the radiator, something someone replacing a std with a
complete new TRV would like to know.

That question stands.

I think has been answered elsewhere. I think with my experience with
plumbing, unless you are replacing exact like for like, there is a
good chance that something will be different (and rarely in your
favour). ;-(

Cheers, T i m

On Friday, 8 November 2019 10:16:38 UTC, wrote:
On Friday, November 8, 2019 at 10:12:17 AM UTC, wrote:
Is the connection between a radiator tail and the actual valve any sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2" because why would anyone bother setting up for anything else.

Before anyone else jumps in - I retract my assertion that the question (which I asked) is stupid.

On Friday, 8 November 2019 11:33:41 UTC, Dave Plowman (News) wrote:
In article ,
wrote:
On Friday, November 8, 2019 at 10:12:17 AM UTC, wrote:
Is the connection between a radiator tail and the actual valve any
sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2"

As noted elsewhere, I asked the question.

because why would anyone bother setting up for anything else.

You've rather obviously never done this job. The centres of the pipe and
rad can be different between a LSV and TRV, as can the length of the pipe.
Even the type of olive used different.

Damn. I have actually done it before (and had to change the tails), but everything looked a bit more standard this time. If I have to change everything I guess I'll give it all a flush too.

On 08/11/2019 10:12, wrote:
Is the connection between a radiator tail and the actual valve any sort of standard? And/or the overall "width" of the valve?

I'm trying to work out what my chances are of swapping the existing valves for TRVs without fitting new tails and adjusting the pipework.

Since it's cold, I want, for a change, to estimate the duration of the work before I start it.


You may get away with it if the physical size of the valves (inlet to
outlet) match.

When I replace all my 20 year old TRV I had to change the tails in the
radiator. The valve body on the old TRV was longer. In addition I found
the screw thread on the compression nut on the old fitting did not match
that on the new fitting necessitating removing the olive in order to fit
the new nut. On many pipes removing the old olive was difficult and I
found it easier to cut the old pipe and solder in a new piece. The
exercise was complicated by the pipes having been painted and having to
syphon any water out of the existing pipe(s) before soldering.

For the tails I already had
https://www.screwfix.com/p/rothenber...-spanner/95088
which made this part of the job much easier.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On Friday, 8 November 2019 12:02:37 UTC, alan_m wrote:
For the tails I already had
https://www.screwfix.com/p/rothenber...-spanner/95088
which made this part of the job much easier.

That tool looks like a vast improvement on the radiator spanner I used last time. I used a radiator spanner and ended up having to hit it with a hammer to get it to shift.

As I was living in a flat, and doing the work in evenings, I did that particular job on bonfire night to minimise disturbance to everyone else.

On 08/11/2019 10:12, wrote:
Is the connection between a radiator tail and the actual valve any sort of standard? And/or the overall "width" of the valve?

I'm trying to work out what my chances are of swapping the existing valves for TRVs without fitting new tails and adjusting the pipework.

Since it's cold, I want, for a change, to estimate the duration of the work before I start it.


Photo might help as I think there's a British Standard for radiator
tails so there's a fair chance you'll be OK - /if/ (a) you start off
with ones that conform and (b) know the pipe size/material and angle.



--
Robin
reply-to address is (intended to be) valid

On 08/11/2019 12:07, wrote:
On Friday, 8 November 2019 12:02:37 UTC, alan_m wrote:
For the tails I already had
https://www.screwfix.com/p/rothenber...-spanner/95088
which made this part of the job much easier.

That tool looks like a vast improvement on the radiator spanner I used last time. I used a radiator spanner and ended up having to hit it with a hammer to get it to shift.

As I was living in a flat, and doing the work in evenings, I did that particular job on bonfire night to minimise disturbance to everyone else.



The ratchet handle is the same as you get with a 1/2 inch socket set for
a car etc. so if you already have this maybe the stepped socket can be
purchased separately. I don't know if the Screwfix is the same as mine
as the one I have also has deep grooves in two faces of the hex steps to
suite the fittings that have two internal lugs. This is shown in

https://www.ebay.co.uk/itm/Todays-To...AOSwItRdVSl v

or

https://tinyurl.com/y64h5tk4




--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 08/11/2019 10:16, wrote:
On Friday, November 8, 2019 at 10:12:17 AM UTC,
wrote:
Is the connection between a radiator tail and the actual valve any
sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2"
because why would anyone bother setting up for anything else.

Well its not as daft as it sounds...

The tail socket into the rad is almost always 1/2" BSP female. However
the other end of the tail varies. Traditionally it was a cone fitting
retained by a 3/4" BSP nut that was captive on the tail. However more
commonly these days the tail is often just a length of 15 mm pipe, and
the valve has a 15mm compression fitting that then connects to that
(ultimately leaving a 1/2" BSP not captive on the tail, but retained by
the olive rather than the cone fitting).





--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 08/11/2019 12:16, Robin wrote:
On 08/11/2019 10:12, wrote:
Is the connection between a radiator tail and the actual valve any
sort of standard? And/or the overall "width" of the valve?

I'm trying to work out what my chances are of swapping the existing
valves for TRVs without fitting new tails and adjusting the pipework.

Since it's cold, I want, for a change,Â* to estimate the duration of
the work before I start it.


Photo might help as I think there's a British Standard for radiator
tails so there's a fair chance you'll be OK - /if/ (a) you start off
with ones that conform and (b) know the pipe size/material and angle.


Ahem, pl. replace" tails" by "valves".


--
Robin
reply-to address is (intended to be) valid

In article ,
John Rumm wrote:
On 08/11/2019 10:16, wrote:
On Friday, November 8, 2019 at 10:12:17 AM UTC,
wrote:
Is the connection between a radiator tail and the actual valve any
sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2"
because why would anyone bother setting up for anything else.

Well its not as daft as it sounds...

The tail socket into the rad is almost always 1/2" BSP female. However
the other end of the tail varies. Traditionally it was a cone fitting
retained by a 3/4" BSP nut that was captive on the tail. However more
commonly these days the tail is often just a length of 15 mm pipe, and
the valve has a 15mm compression fitting that then connects to that
(ultimately leaving a 1/2" BSP not captive on the tail, but retained by
the olive rather than the cone fitting).

My original TRVs, shed own brand, had an 'olive' which fitted to the end
of the copper pipe, rather than the usual types which fits over it. And
when replacement time came, couldn't find the same design.

But I'd only buy Drayton now. Saving a few pennies isn't worth it in the
long run.

--
*A cubicle is just a padded cell without a door.

Dave Plowman London SW
To e-mail, change noise into sound.

On 08/11/2019 10:12, wrote:
Is the connection between a radiator tail and the actual valve any sort of standard? And/or the overall "width" of the valve?

I'm trying to work out what my chances are of swapping the existing valves for TRVs without fitting new tails and adjusting the pipework.


I would have thought that the chances are minimal. The job will be
easier if there is a section of pipe that is horizontal below the level
of the radiator bottom.

I prefer to use a programmable thermostat as these allow the temperature
to be automatically varied through out the day. I had a similar problem
when I removed some old TRVs some of which were leaking.

--
Michael Chare

On 08/11/2019 12:47, John Rumm wrote:
On 08/11/2019 10:16, wrote:
On Friday, November 8, 2019 at 10:12:17 AM UTC,
wrote:
Is the connection between a radiator tail and the actual valve any
sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2"
because why would anyone bother setting up for anything else.

Well its not as daft as it sounds...

The tail socket into the rad is almost always 1/2" BSP female. However
the other end of the tail varies. Traditionally it was a cone fitting
retained by a 3/4" BSP nut that was captive on the tail. However more
commonly these days the tail is often just a length of 15 mm pipe, and
the valve has a 15mm compression fitting that then connects to that
(ultimately leaving a 1/2" BSP not captive on the tail, but retained by
the olive rather than the cone fitting).


Definitely do not assume standard threads, you may have to remove the
fitting that goes into the radiator, rather than just swapping the
"valve" bit. This needs a big allen key and they are sometimes very
tight from corrosion. In my experience you can usually get away with the
slightly different dimensions by using the flexibility of the copper
pipes, provided they are not too constrained close to the radiator. One
of those jobs that usually takes longer than expected, IME.

On Fri, 8 Nov 2019 12:02:32 +0000, alan_m wrote:

On 08/11/2019 10:12, wrote:
Is the connection between a radiator tail and the actual valve any sort of standard? And/or the overall "width" of the valve?

I'm trying to work out what my chances are of swapping the existing valves for TRVs without fitting new tails and adjusting the pipework.

Since it's cold, I want, for a change, to estimate the duration of the work before I start it.


You may get away with it if the physical size of the valves (inlet to
outlet) match.

When I replace all my 20 year old TRV I had to change the tails in the
radiator. The valve body on the old TRV was longer. In addition I found
the screw thread on the compression nut on the old fitting did not match
that on the new fitting necessitating removing the olive in order to fit
the new nut. On many pipes removing the old olive was difficult and I
found it easier to cut the old pipe and solder in a new piece. The
exercise was complicated by the pipes having been painted and having to
syphon any water out of the existing pipe(s) before soldering.

For the tails I already had
https://www.screwfix.com/p/rothenber...-spanner/95088
which made this part of the job much easier.

Faced with removing old olives, no chance of a tool and pipes up from
concrete floors, I found that a junior hacksaw, cutting diagonally across
the olive so that it didn't damage the pipe, worked well. Cut the slot to
within a gnat's of the pipe - it'll probably spring open for a v. short way
as it gets weaker - then screwdriver finishes the job.
--
Peter.
The gods will stay away
whilst religions hold sway

On 08/11/2019 17:02, newshound wrote:
On 08/11/2019 12:47, John Rumm wrote:
On 08/11/2019 10:16, wrote:
On Friday, November 8, 2019 at 10:12:17 AM UTC,
wrote:
Is the connection between a radiator tail and the actual valve any
sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2"
because why would anyone bother setting up for anything else.

Well its not as daft as it sounds...

The tail socket into the rad is almost always 1/2" BSP female. However
the other end of the tail varies. Traditionally it was a cone fitting
retained by a 3/4" BSP nut that was captive on the tail. However more
commonly these days the tail is often just a length of 15 mm pipe, and
the valve has a 15mm compression fitting that then connects to that
(ultimately leaving a 1/2" BSP not captive on the tail, but retained
by the olive rather than the cone fitting).


Definitely do not assume standard threads, you may have to remove the
fitting that goes into the radiator, rather than just swapping the
"valve" bit. This needs a big allen key and they are sometimes very
tight from corrosion. In my experience you can usually get away with the

Some of the modern ones seem to use a couple of flats on the stem to
allow them to be turned with a spanner, rather than having the hex inner
profile... Personally I prefer the hex versions.

slightly different dimensions by using the flexibility of the copper
pipes, provided they are not too constrained close to the radiator. One
of those jobs that usually takes longer than expected, IME.

Yup, although sometimes you get lucky...


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 08/11/2019 11:40, T i m wrote:
On Fri, 8 Nov 2019 03:18:08 -0800 (PST), wrote:

On Friday, November 8, 2019 at 11:12:09 AM UTC, T i m wrote:
On Fri, 8 Nov 2019 02:16:35 -0800 (PST), wrote:

On Friday, November 8, 2019 at 10:12:17 AM UTC, wrote:
Is the connection between a radiator tail and the actual valve any sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2" because why would anyone bother setting up for anything else.

I think you have missed the point of the question by snipping and only
replying to one bit (missing the 'bigger picture' in the process).

Not quite, because I replied to my own question!

Doh! ;-)

It wasn't the diameter of the input pipe,

I was referring to the size of thread that connects the valve to the tail, and realised that surely no one would make it anything other than 3/4 or 1/2, so if it looks like a 1/2, it is a 1/2.

Well, I'm not sure you can even assume they will be interchangeable,
even if they are nominally the same size / type of fitting.

I say that because I have gone to replace say a gate valve and hoped
to retain the existing nuts / olives, only to find the thread a
different pitch / tightness?

it was the distance between
that pipe and the radiator, something someone replacing a std with a
complete new TRV would like to know.

That question stands.

I think has been answered elsewhere. I think with my experience with
plumbing, unless you are replacing exact like for like, there is a
good chance that something will be different (and rarely in your
favour). ;-(

I have certainly found in the past that things were not interchangeable
- even nuts from one compression fitting to another - but everything I
have used in recent years has been (replacing gate valves with lever
ball valves, straight couplers with isolation valves and the like).
Maybe manufacturers used their own standards in the past, but these days
do stick to standard lengths and threads?

SteveW

Steve Walker wrote:

On 08/11/2019 11:40, T i m wrote:
On Fri, 8 Nov 2019 03:18:08 -0800 (PST), wrote:

On Friday, November 8, 2019 at 11:12:09 AM UTC, T i m wrote:
On Fri, 8 Nov 2019 02:16:35 -0800 (PST), wrote:

On Friday, November 8, 2019 at 10:12:17 AM UTC,
wrote: Is the connection between a radiator tail and the actual
valve any sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2"
because why would anyone bother setting up for anything else.

I think you have missed the point of the question by snipping and only
replying to one bit (missing the 'bigger picture' in the process).

Not quite, because I replied to my own question!

Doh! ;-)

It wasn't the diameter of the input pipe,

I was referring to the size of thread that connects the valve to the
tail, and realised that surely no one would make it anything other than
3/4 or 1/2, so if it looks like a 1/2, it is a 1/2.

Well, I'm not sure you can even assume they will be interchangeable,
even if they are nominally the same size / type of fitting.

I say that because I have gone to replace say a gate valve and hoped
to retain the existing nuts / olives, only to find the thread a
different pitch / tightness?

it was the distance between
that pipe and the radiator, something someone replacing a std with a
complete new TRV would like to know.

That question stands.

I think has been answered elsewhere. I think with my experience with
plumbing, unless you are replacing exact like for like, there is a
good chance that something will be different (and rarely in your
favour). ;-(

I have certainly found in the past that things were not interchangeable
- even nuts from one compression fitting to another - but everything I
have used in recent years has been (replacing gate valves with lever
ball valves, straight couplers with isolation valves and the like).
Maybe manufacturers used their own standards in the past, but these days
do stick to standard lengths and threads?

SteveW

There used to be at least two different threads on compression nuts for
domestic size pipes, but in recent years they all seem to be BSP, I
would really expect any domestic radiator valves in the last 15 years or
so to be directly interchangeable. ICB, and when I was in a hurry
probably would be.



--

Roger Hayter

On 09/11/2019 01:05, Roger Hayter wrote:

There used to be at least two different threads on compression nuts for
domestic size pipes, but in recent years they all seem to be BSP, I
would really expect any domestic radiator valves in the last 15 years or
so to be directly interchangeable. ICB, and when I was in a hurry
probably would be.


Last year I had to replace a 3 port (CH) valve where the old one was
less than 10 years old. The threads didn't match.

At first it did appear to tighten up but I had a small weeping leak.
Comparing the old and new treads they appeared to be the same pitch but
a slightly different angle. After draining down for a second time and
removing the old nut I tried it on the new fitting. It tuned a few times
but then just started to bind up on the new fitting.


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

You can often find dimensioned drawings on the manufacturer's web page.

On 08/11/2019 18:10, John Rumm wrote:
On 08/11/2019 17:02, newshound wrote:
On 08/11/2019 12:47, John Rumm wrote:
On 08/11/2019 10:16, wrote:
On Friday, November 8, 2019 at 10:12:17 AM UTC,
wrote:
Is the connection between a radiator tail and the actual valve any
sort of standard?

This bit is a stupid question isn't it. It must be either 3/4 or 1/2"
because why would anyone bother setting up for anything else.

Well its not as daft as it sounds...

The tail socket into the rad is almost always 1/2" BSP female.
However the other end of the tail varies. Traditionally it was a cone
fitting retained by a 3/4" BSP nut that was captive on the tail.
However more commonly these days the tail is often just a length of
15 mm pipe, and the valve has a 15mm compression fitting that then
connects to that (ultimately leaving a 1/2" BSP not captive on the
tail, but retained by the olive rather than the cone fitting).


Definitely do not assume standard threads, you may have to remove the
fitting that goes into the radiator, rather than just swapping the
"valve" bit. This needs a big allen key and they are sometimes very
tight from corrosion. In my experience you can usually get away with the

Some of the modern ones seem to use a couple of flats on the stem to
allow them to be turned with a spanner, rather than having the hex inner
profile... Personally I prefer the hex versions.

slightly different dimensions by using the flexibility of the copper
pipes, provided they are not too constrained close to the radiator.
One of those jobs that usually takes longer than expected, IME.

Yup, although sometimes you get lucky...



The original rads in my 1976-built house have 3/4 inch female
BSP socket, and the valves were fitted by a Gorilla using
boss white and hemp.

On 08/11/2019 12:26, alan_m wrote:
On 08/11/2019 12:07, wrote:
On Friday, 8 November 2019 12:02:37 UTC, alan_mÂ* wrote:
For the tails I already had
https://www.screwfix.com/p/rothenber...-spanner/95088
which made this part of the job much easier.

That tool looks like a vast improvement on the radiator spanner I used
last time. I used a radiator spanner and ended up having to hit it
with a hammer to get it to shift.

As I was living in a flat, and doing the work in evenings, I did that
particular job on bonfire night to minimise disturbance to everyone else.



The ratchet handle is the same as you get with a 1/2 inch socket set for
a car etc.Â* so if you already have this maybe the stepped socket can be
purchased separately. I don't know if the Screwfix is the same as mine
as the one I have also has deep grooves in two faces of the hex steps to
suite the fittings that have two internal lugs. This is shown in

https://www.ebay.co.uk/itm/Todays-To...AOSwItRdVSl v


or

https://tinyurl.com/y64h5tk4




That Rothenburger ratchet handle appears to have a female 1/2
inch fitting, whereas all the car ratchets I have seen have
a 1/2 (or 1/4, 3/8) male fitting.

On 09/11/2019 14:31, Andrew wrote:


That Rothenburger ratchet handle appears to have a female 1/2
inch fitting, whereas all the car ratchets I have seen have
a 1/2 (or 1/4, 3/8) male fitting.

I have two types of 1/2 inch ratchet handles that cane with car socket sets.

One has a level to select tighten/undo and has a male fitting.

The other has to be turned over to change the direction and the male 1/2
inch square fitting has to be manually pushed through when the handle is
turned over. This "double" male fitting can be removed to leave a 1/2
inch female fitting in the ratchet handle.

However you are correct in that most ratchet handles on sale seem to be
of the type with only a male drive fitting where the radiator adapter
alone would not fit


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk