I am trying to test some radiators for leaks, having had one fail in
my daughter's house I thought the tail to valve connection would be
22mm but a normal stop end has a different thread. Can anyone tell me
the likely threat size else I will have to replace valves as well as
radiator? It measures 30mm across the flats whereas my 22mm stop end
is 31mm.

AJH

On Tue, 07 Feb 2017 13:11:54 +0000, news wrote:

I am trying to test some radiators for leaks, having had one fail in my
daughter's house I thought the tail to valve connection would be 22mm
but a normal stop end has a different thread. Can anyone tell me the
likely threat size else I will have to replace valves as well as
radiator? It measures 30mm across the flats whereas my 22mm stop end is
31mm.

Usually either 1/2 or 3/4" BSP. Readily available at all plumbers
merchants, they usually come complete with new valves, so make sure you
ask for the right size.

On 2/7/2017 6:43 PM, Alan wrote:
On Tue, 07 Feb 2017 13:11:54 +0000, news wrote:

I am trying to test some radiators for leaks, having had one fail in my
daughter's house I thought the tail to valve connection would be 22mm
but a normal stop end has a different thread. Can anyone tell me the
likely threat size else I will have to replace valves as well as
radiator? It measures 30mm across the flats whereas my 22mm stop end is
31mm.

Usually either 1/2 or 3/4" BSP. Readily available at all plumbers
merchants, they usually come complete with new valves, so make sure you
ask for the right size.

I forget the details, but don't you find two threads of similar diameter
but different pitch on radiator valves?

On Tue, 7 Feb 2017 21:52:06 +0000, newshound
wrote:

On 2/7/2017 6:43 PM, Alan wrote:
On Tue, 07 Feb 2017 13:11:54 +0000, news wrote:

I am trying to test some radiators for leaks, having had one fail in my
daughter's house I thought the tail to valve connection would be 22mm
but a normal stop end has a different thread. Can anyone tell me the
likely threat size else I will have to replace valves as well as
radiator? It measures 30mm across the flats whereas my 22mm stop end is
31mm.

Usually either 1/2 or 3/4" BSP. Readily available at all plumbers
merchants, they usually come complete with new valves, so make sure you
ask for the right size.

I forget the details, but don't you find two threads of similar diameter
but different pitch on radiator valves?

I'll get a 3/4 BSP flanged plug and try it tomorrow

AJH

On Tuesday, 7 February 2017 22:33:42 UTC, wrote:
On Tue, 7 Feb 2017 21:52:06 +0000, newshound
wrote:

On 2/7/2017 6:43 PM, Alan wrote:
On Tue, 07 Feb 2017 13:11:54 +0000, news wrote:

I am trying to test some radiators for leaks, having had one fail in my
daughter's house I thought the tail to valve connection would be 22mm
but a normal stop end has a different thread. Can anyone tell me the
likely threat size else I will have to replace valves as well as
radiator? It measures 30mm across the flats whereas my 22mm stop end is
31mm.

Usually either 1/2 or 3/4" BSP. Readily available at all plumbers
merchants, they usually come complete with new valves, so make sure you
ask for the right size.

I forget the details, but don't you find two threads of similar diameter
but different pitch on radiator valves?

I'll get a 3/4 BSP flanged plug and try it tomorrow

AJH

Radiator connections are taper thread.

wrote:

I am trying to test some radiators for leaks, having had one fail in
my daughter's house I thought the tail to valve connection would be
22mm but a normal stop end has a different thread. Can anyone tell me
the likely threat size else I will have to replace valves as well as
radiator? It measures 30mm across the flats whereas my 22mm stop end
is 31mm.

AJH
I'm pretty sure the cross flats size is an unreliable guide, even
ordinary compression fittings do not seem at all consistent in this
respect. But the thread on compression fitting nuts is not a standard
BSP thread either AFAICS. Nor has the same thread always been used on
compression fittings. You many need to replace the fitting that
actually screws into the radiator with the one from the new valve, and
that is actually a standard BSP taper thread I think.



--

Roger Hayter

On Wed, 8 Feb 2017 12:04:18 +0000, (Roger Hayter)
wrote:

wrote:

I am trying to test some radiators for leaks, having had one fail in
my daughter's house I thought the tail to valve connection would be
22mm but a normal stop end has a different thread. Can anyone tell me
the likely threat size else I will have to replace valves as well as
radiator? It measures 30mm across the flats whereas my 22mm stop end
is 31mm.

AJH
I'm pretty sure the cross flats size is an unreliable guide, even
ordinary compression fittings do not seem at all consistent in this
respect. But the thread on compression fitting nuts is not a standard
BSP thread either AFAICS. Nor has the same thread always been used on
compression fittings. You many need to replace the fitting that
actually screws into the radiator with the one from the new valve, and
that is actually a standard BSP taper thread I think.

Yes the standard 22mm compression fitting is not a BSP thread but the
radiator tail to the valve is 3/4 BSP. I'm waiting for a 1/2" allen
key to take the tail from the radiator then I need to find a 15MM
radiator tail with a 3/4" BSP nut and olive which I can cut to length
to fit the new radiator. Else I shall make one by extending the old
tails.

I'll need to test all the radiators for leaks, I can only assume this
one went because of lack of or weak inhibitor but the rest may be on
their way out. I'll try and pressurise them with air and see if they
blow bubbles with soapy water.


AJH

On 2/8/2017 1:43 PM, wrote:
On Wed, 8 Feb 2017 12:04:18 +0000, (Roger Hayter)
wrote:

wrote:

I am trying to test some radiators for leaks, having had one fail in
my daughter's house I thought the tail to valve connection would be
22mm but a normal stop end has a different thread. Can anyone tell me
the likely threat size else I will have to replace valves as well as
radiator? It measures 30mm across the flats whereas my 22mm stop end
is 31mm.

AJH
I'm pretty sure the cross flats size is an unreliable guide, even
ordinary compression fittings do not seem at all consistent in this
respect. But the thread on compression fitting nuts is not a standard
BSP thread either AFAICS. Nor has the same thread always been used on
compression fittings. You many need to replace the fitting that
actually screws into the radiator with the one from the new valve, and
that is actually a standard BSP taper thread I think.

Yes the standard 22mm compression fitting is not a BSP thread but the
radiator tail to the valve is 3/4 BSP. I'm waiting for a 1/2" allen
key to take the tail from the radiator then I need to find a 15MM
radiator tail with a 3/4" BSP nut and olive which I can cut to length
to fit the new radiator. Else I shall make one by extending the old
tails.

I'll need to test all the radiators for leaks, I can only assume this
one went because of lack of or weak inhibitor but the rest may be on
their way out. I'll try and pressurise them with air and see if they
blow bubbles with soapy water.


AJH

IIRC the compression fitting for 15 mm pipe on radiator valves is
sometimes 3/4 BSP, sometimes not.

On Wednesday, 8 February 2017 12:04:22 UTC, Roger Hayter wrote:
wrote:

I am trying to test some radiators for leaks, having had one fail in
my daughter's house I thought the tail to valve connection would be
22mm but a normal stop end has a different thread. Can anyone tell me
the likely threat size else I will have to replace valves as well as
radiator? It measures 30mm across the flats whereas my 22mm stop end
is 31mm.

AJH
I'm pretty sure the cross flats size is an unreliable guide, even
ordinary compression fittings do not seem at all consistent in this
respect. But the thread on compression fitting nuts is not a standard
BSP thread either AFAICS. Nor has the same thread always been used on
compression fittings. You many need to replace the fitting that
actually screws into the radiator with the one from the new valve, and
that is actually a standard BSP taper thread I think.

The thread on the pipe is BSP.
The thread on the nut may or may not be.