Not a want as such just put my mind at ease.

I spent today running co-ax cable from the loft to run the telly free view.
This co-ax/freeview is emergency back up for if the Fire TV stick
/internet fails
So fire stick fall back to Freeview because I got ****ed of paying
Virgin[1] to watch ads.

I was fairly careful when I was running the co-ax down various 'holes'
not to touch pipework, I am worried though that the cable may move and
touch the pipework .
Will the co-ax cope with touching domestic hot water pipes or will this
heat load cause the cable insulation to degrade or off-gas?

[1] Have decided to ditch Virgin altogether (had phone,TV and internet
from them). And move to Vodaphone. They have installed gigafast cable
to here (Balerno outskirts of Edinburgh[one of only 15 cities to get
gigafast]) so getting internet from them, they 'throw' in a phone line .
TV as 'said' Firestick with freeview backup.

On 14/11/2020 17:21, soup wrote:
Not a want as such just put my mind at ease.

I spent today running co-ax cable from the loft to run the telly free view.
This co-ax/freeview is emergency back up for if the Fire TV stick
/internet fails
So fire stick fall back to Freeview because I got ****ed of paying
Virgin[1] to watch ads.

I was fairly careful when I was running the co-ax down various 'holes'
not to touch pipework, I am worried though that the cable may move and
touch the pipework .
Will the co-ax cope with touching domestic hot water pipes or will this
heat load cause the cable insulation to degrade or off-gas?

[1] Have decided to ditch Virgin altogether (had phone,TV and internet
from them).Â* And move to Vodaphone. They have installed gigafast cable
to here (Balerno outskirts of Edinburgh[one of only 15 cities to get
gigafast]) so getting internet from them, they 'throw' in a phone line .
TV as 'said' Firestick with freeview backup.

If you bought decent coax like 'CT100' or whatever its latest
incarnation is called, then it won't matter what it touches as
long as you didn't crush it or bend about 2 inches of it into a
90 degree bend. I always assume the curvature on inside of the reel
it came on is the minimum you should use.

On 14/11/2020 17:21, soup wrote:
Not a want as such just put my mind at ease.

I spent today running co-ax cable from the loft to run the telly free view.
This co-ax/freeview is emergency back up for if the Fire TV stick
/internet fails
So fire stick fall back to Freeview because I got ****ed of paying
Virgin[1] to watch ads.

I was fairly careful when I was running the co-ax down various 'holes'
not to touch pipework, I am worried though that the cable may move and
touch the pipework .
Will the co-ax cope with touching domestic hot water pipes or will this
heat load cause the cable insulation to degrade or off-gas?

[1] Have decided to ditch Virgin altogether (had phone,TV and internet
from them).Â* And move to Vodaphone. They have installed gigafast cable
to here (Balerno outskirts of Edinburgh[one of only 15 cities to get
gigafast]) so getting internet from them, they 'throw' in a phone line .
TV as 'said' Firestick with freeview backup.

It is not a good idea to have pvc insulation in permanant contact with
central heating hot water pipes. Could you not use clips to secure the
coax away from the pipes?

On 14/11/2020 17:32, Jack Harry Teesdale wrote:
On 14/11/2020 17:21, soup wrote:
Not a want as such just put my mind at ease.

I spent today running co-ax cable from the loft to run the telly free
view.
This co-ax/freeview is emergency back up for if the Fire TV stick
/internet fails
So fire stick fall back to Freeview because I got ****ed of paying
Virgin[1] to watch ads.

I was fairly careful when I was running the co-ax down various 'holes'
not to touch pipework, I am worried though that the cable may move and
touch the pipework .
Will the co-ax cope with touching domestic hot water pipes or will
this heat load cause the cable insulation to degrade or off-gas?

[1] Have decided to ditch Virgin altogether (had phone,TV and internet
from them).Â* And move to Vodaphone. They have installed gigafast cable
to here (Balerno outskirts of Edinburgh[one of only 15 cities to get
gigafast]) so getting internet from them, they 'throw' in a phone line .
TV as 'said' Firestick with freeview backup.

It is not a good idea to have pvc insulation in permanant contact with
central heating hot water pipes. Could you not use clips to secure the
coax away from the pipes?

Why not ?. It survives UV light out of doors.

On 14/11/2020 17:21, soup wrote:
I spent today running co-ax cable from the loft to run the telly free view.
This co-ax/freeview is emergency back up for if the Fire TV stick
/internet fails
So fire stick fall back to Freeview because I got ****ed of paying
Virgin[1] to watch ads.

I was fairly careful when I was running the co-ax down various 'holes'
not to touch pipework, I am worried though that the cable may move and
touch the pipework .
Will the co-ax cope with touching domestic hot water pipes or will this
heat load cause the cable insulation to degrade or off-gas?


I never encountered this problem in my lifetime of working in the aerial
and satellite business.

Saw plenty of heat-affected coax, but it was always after house fires!

Bill

Well, I'd personally not want to run coaxial tv cable along with hot pipes
myself. I guess what happens and how long it takes to happen depends on your
signals in the area.
Can you not strap a bit of the coax you are using to a water pipe
soomewhere with a couple of loose cable ties and see what occurs?
Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"soup" wrote in message
...
Not a want as such just put my mind at ease.

I spent today running co-ax cable from the loft to run the telly free
view.
This co-ax/freeview is emergency back up for if the Fire TV stick
/internet fails
So fire stick fall back to Freeview because I got ****ed of paying
Virgin[1] to watch ads.

I was fairly careful when I was running the co-ax down various 'holes' not
to touch pipework, I am worried though that the cable may move and touch
the pipework .
Will the co-ax cope with touching domestic hot water pipes or will this
heat load cause the cable insulation to degrade or off-gas?

[1] Have decided to ditch Virgin altogether (had phone,TV and internet
from them). And move to Vodaphone. They have installed gigafast cable to
here (Balerno outskirts of Edinburgh[one of only 15 cities to get
gigafast]) so getting internet from them, they 'throw' in a phone line .
TV as 'said' Firestick with freeview backup.

Yes and some sorts of coax you would be hard pressed to bend it like that
anyway, A far cry from the so called low loss stuff we used to use in
analogue days with about as much braid as hair on a billiard ball.
Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Andrew" wrote in message
...
On 14/11/2020 17:21, soup wrote:
Not a want as such just put my mind at ease.

I spent today running co-ax cable from the loft to run the telly free
view.
This co-ax/freeview is emergency back up for if the Fire TV stick
/internet fails
So fire stick fall back to Freeview because I got ****ed of paying
Virgin[1] to watch ads.

I was fairly careful when I was running the co-ax down various 'holes'
not to touch pipework, I am worried though that the cable may move and
touch the pipework .
Will the co-ax cope with touching domestic hot water pipes or will this
heat load cause the cable insulation to degrade or off-gas?

[1] Have decided to ditch Virgin altogether (had phone,TV and internet
from them). And move to Vodaphone. They have installed gigafast cable to
here (Balerno outskirts of Edinburgh[one of only 15 cities to get
gigafast]) so getting internet from them, they 'throw' in a phone line .
TV as 'said' Firestick with freeview backup.

If you bought decent coax like 'CT100' or whatever its latest
incarnation is called, then it won't matter what it touches as
long as you didn't crush it or bend about 2 inches of it into a
90 degree bend. I always assume the curvature on inside of the reel
it came on is the minimum you should use.

"soup" wrote in message
...

I was fairly careful when I was running the co-ax down various 'holes' not to touch
pipework, I am worried though that the cable may move and touch the pipework .
Will the co-ax cope with touching domestic hot water pipes or will this heat load cause
the cable insulation to degrade or off-gas?

Is what you mean ttat the coax may touch the pipes when going through the holes ?

Could you not sheath the co-ax with a couple of turnings of heat resistant
tape at those points ? You'd need to slacken it off from end or one or other
apply the tape and pulll it back through I'd imagine,


https://www.amazon.co.uk/Heat-Resist.../dp/B005GPLY4K


michael adams

.....

All plastics have melting points above the boiling point of water.
Central heating systems do not run at boiling point. A round
cross-section cable touching a round cross-section pipe wouldn't have a
large area of contact but the cable would have a large surface area with
which to dissipate heat.

Like I said before (and it seems nobody was taking a blind bit of
notice) in a lifetime of fixing aerials and dishes I never once saw this
problem.

Bill

"williamwright" wrote in message
...

All plastics have melting points above the boiling point of water. Central heating
systems do not run at boiling point. A round cross-section cable touching a round
cross-section pipe wouldn't have a large area of contact but the cable would have a
large surface area with which to dissipate heat.

Like I said before (and it seems nobody was taking a blind bit of notice) in a lifetime
of fixing aerials and dishes I never once saw this problem.

Bill

Out of curiosity I found the following

Clip On Hot Water Pipe Thermometer 0-120C 63MM Temperature Gauge

https://www.amazon.co.uk/Thermometer.../dp/B01N8SQS54

Which goes up to 120C Which suggests the pipes themselves can exceed
the temperature of boiling water which is 100C. Most other pipe
thermometers seem to go to 120C as well. Not that I'd claim to
understand how this makes any sense.

Then there's this

quote

Polyethylene and polyvinyl chloride are used as insulators. These two
plastics have relatively low melting points, and can start to soften at
temperatures as low as 150 degrees F. [65 C]
If the insulation is exposed to low heat over long periods of time, the
position of the center conductor in relation to the shielding may shift
as the hot plastics yield. If the center conductor and shielding
touch, signal never makes it past that point. Coax should be kept away
from heatsinks, stage lights, and other sources of heat

quote
https://www.rfvenue.com/blog/2015/02...cable-goes-bad


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may cause
the problem

Or not, in your experience apparently.


michael adams

....

michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may cause
the problem

So youre taking the calibrated scale of a thermometer as an indication of
typical CH water temperatures?

Tim

--
Please don't feed the trolls

On 14/11/2020 20:14, Tim+ wrote:
michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may cause
the problem

So youre taking the calibrated scale of a thermometer as an indication of
typical CH water temperatures?

Tim

Boiling point of water at 3 bar is about 134 deg C. IIRC boiler gauges
typically go to 3 bar, presumably relief valves are slightly less.

On 14/11/2020 19:44, michael adams wrote:
"williamwright" wrote in message
...

All plastics have melting points above the boiling point of water. Central heating
systems do not run at boiling point. A round cross-section cable touching a round
cross-section pipe wouldn't have a large area of contact but the cable would have a
large surface area with which to dissipate heat.

Like I said before (and it seems nobody was taking a blind bit of notice) in a lifetime
of fixing aerials and dishes I never once saw this problem.

Bill

Out of curiosity I found the following

Clip On Hot Water Pipe Thermometer 0-120C 63MM Temperature Gauge

https://www.amazon.co.uk/Thermometer.../dp/B01N8SQS54

Which goes up to 120C Which suggests the pipes themselves can exceed
the temperature of boiling water which is 100C. Most other pipe
thermometers seem to go to 120C as well. Not that I'd claim to
understand how this makes any sense.

But if you clip it on to a CH pipe or domestic hot water pipe the
reading will be around 70C.

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

"Tim+" wrote in message
...
michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may cause
the problem

So you're taking the calibrated scale of a thermometer as an indication of
typical CH water temperatures?

Er, no ? As I said above, it's the pipes themselves which are 120C, it being
a pipe thermometer, after all. Not necessarily a CH water thermometer, at
least as far as I know.

Quite what the relationship between the two may be I don't claim
to know But it's the temperature of the pipe rather than the water
inside it, which is of the most relevance here.

And its relationship of that temperature - in the confined space of a
hole don't forget, to the temporaries at which it's claimed the
plastic components of a co-ax lead may start to soften which is
of most potential interest.


michael adams

....

"alan_m" wrote in message
...
On 14/11/2020 19:44, michael adams wrote:
"williamwright" wrote in message
...

All plastics have melting points above the boiling point of water. Central heating
systems do not run at boiling point. A round cross-section cable touching a round
cross-section pipe wouldn't have a large area of contact but the cable would have a
large surface area with which to dissipate heat.

Like I said before (and it seems nobody was taking a blind bit of notice) in a
lifetime
of fixing aerials and dishes I never once saw this problem.

Bill

Out of curiosity I found the following

Clip On Hot Water Pipe Thermometer 0-120C 63MM Temperature Gauge

https://www.amazon.co.uk/Thermometer.../dp/B01N8SQS54

Which goes up to 120C Which suggests the pipes themselves can exceed
the temperature of boiling water which is 100C. Most other pipe
thermometers seem to go to 120C as well. Not that I'd claim to
understand how this makes any sense.

But if you clip it on to a CH pipe or domestic hot water pipe the reading will be
around 70C.

I'm quite prepared to believe you. But then why have thermometers that go up to 120C
if there's no need ?


michael adams

.....

"soup" wrote in message
...
Not a want as such just put my mind at ease.

I spent today running co-ax cable from the loft to run the telly free
view.
This co-ax/freeview is emergency back up for if the Fire TV stick
/internet fails
So fire stick fall back to Freeview because I got ****ed of paying
Virgin[1] to watch ads.

I was fairly careful when I was running the co-ax down various 'holes' not
to touch pipework, I am worried though that the cable may move and touch
the pipework .
Will the co-ax cope with touching domestic hot water pipes or will this
heat load cause the cable insulation to degrade or off-gas?

[1] Have decided to ditch Virgin altogether (had phone,TV and internet
from them). And move to Vodaphone. They have installed gigafast cable to
here (Balerno outskirts of Edinburgh[one of only 15 cities to get
gigafast]) so getting internet from them, they 'throw' in a phone line .
TV as 'said' Firestick with freeview backup.

sorry to hijack this

but what does FS do for me.

assuming that I'm not prepared to sub to Netflix or whatever what does it
give me

Just the main 5 channel catch up services (plus their baby channels)

or something more?

TIA

tim

michael adams wrote on 14/11/2020 :
Which goes up to 120C Which suggests the pipes themselves can exceed
the temperature of boiling water which is 100C. Most other pipe
thermometers seem to go to 120C as well. Not that I'd claim to
understand how this makes any sense.

It doesn't make any sense, unless it is for use on steam pressurised
heating pipes. Maximum you get on a domestic heating system at the flow
from a boiler, is 80C.

michael adams presented the following explanation :
Er, no ? As I said above, it's the pipes themselves which are 120C, it being
a pipe thermometer, after all. Not necessarily a CH water thermometer, at
least as far as I know.

...and how might the pipe be hotter than the water in contains?

Tim Streater presented the following explanation :
Water doesn't always boil at 100C. Up a mountain where the air pressure is
lower, it boils below 100C. If the water in the CH pipes is at 1 Bar above
atmospheric (as it is here, f'rinstance),

So, 2 Bar, the pressure of a typical combi boiler. The pressure in a
combi boiler system is not there to permit hotter running, it is simply
to allow the system to be a sealed to atmosphere system. A combi
boilers flow temperature is still limited to 80C, more typically it
will run at 50C for best condensing efficiency.

Jack Harry Teesdale laid this down on his screen :
It is not a good idea to have pvc insulation in permanant contact with
central heating hot water pipes. Could you not use clips to secure the coax
away from the pipes?

I have had multiple coax and LAN cables, sharing a duct, unclipped and
no doubt in contact with my heating pipes for the past 40 years. I have
had zero issues and do not expect any.

Harry Bloomfield; "Esq." wrote in message
...
michael adams presented the following explanation :
Er, no ? As I said above, it's the pipes themselves which are 120C, it being
a pipe thermometer, after all. Not necessarily a CH water thermometer, at
least as far as I know.

..and how might the pipe be hotter than the water in contains?

That is indeed the question. But the fact remains that the thermometer
does go up to 120C.

It's no like a car where they may fit an over-optimistic speedometer
that far exceeds any possible speed of the car, which the driver
could never legally attain in most jurisdictions in any case.

So why up to 120C ?



michael adams

....

On 14/11/2020 20:54, michael adams wrote:


But if you clip it on to a CH pipe or domestic hot water pipe the reading will be
around 70C.

I'm quite prepared to believe you. But then why have thermometers that go up to 120C
if there's no need ?


"This pipe temperature gauge can be used on domestic and industrial pipes"

I can think of industrial uses where the temperature of what is in the
pipe exceeds that of a domestic water or CH supply.


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

tim... formulated on Saturday :
or something more?

Lots more is possible, but some breach copyright.

Look up Troypoint.

newshound wrote:
On 14/11/2020 20:14, Tim+ wrote:
michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may cause
the problem

So youre taking the calibrated scale of a thermometer as an indication of
typical CH water temperatures?

Tim

Boiling point of water at 3 bar is about 134 deg C. IIRC boiler gauges
typically go to 3 bar, presumably relief valves are slightly less.


So youre taking the relief pressure valve setting in boilers as an
indication of typical CH water temperature?

Tim

--
Please don't feed the trolls

michael adams wrote:

"Tim+" wrote in message
...
michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may cause
the problem

So you're taking the calibrated scale of a thermometer as an indication of
typical CH water temperatures?

Er, no ? As I said above, it's the pipes themselves which are 120C,

Not in a typical domestic CH system.

Tim

--
Please don't feed the trolls

michael adams wrote:

"alan_m" wrote in message
...
On 14/11/2020 19:44, michael adams wrote:
"williamwright" wrote in message
...

All plastics have melting points above the boiling point of water. Central heating
systems do not run at boiling point. A round cross-section cable touching a round
cross-section pipe wouldn't have a large area of contact but the cable would have a
large surface area with which to dissipate heat.

Like I said before (and it seems nobody was taking a blind bit of notice) in a
lifetime
of fixing aerials and dishes I never once saw this problem.

Bill

Out of curiosity I found the following

Clip On Hot Water Pipe Thermometer 0-120C 63MM Temperature Gauge

https://www.amazon.co.uk/Thermometer.../dp/B01N8SQS54

Which goes up to 120C Which suggests the pipes themselves can exceed
the temperature of boiling water which is 100C. Most other pipe
thermometers seem to go to 120C as well. Not that I'd claim to
understand how this makes any sense.

But if you clip it on to a CH pipe or domestic hot water pipe the reading will be
around 70C.

I'm quite prepared to believe you. But then why have thermometers that go up to 120C
if there's no need ?


Because you might want to clip them onto a pipe that *isnt* in a normal CH
system?

Conceivably a fault condition could cause the temperature to go that high
in a pressurised system but that is a long way from normal operating
temperature.

Tim


--
Please don't feed the trolls

After serious thinking michael adams wrote :
That is indeed the question. But the fact remains that the thermometer
does go up to 120C.

Why not a more than adequate scale range? As you yourself agreed, car
speedos go well beyond the possible maximum. My speedo ranges to
150MPH.

"Harry Bloomfield"; "Esq." wrote in message
...
After serious thinking michael adams wrote :
That is indeed the question. But the fact remains that the thermometer
does go up to 120C.

Why not a more than adequate scale range? As you yourself agreed, car
speedos go well beyond the possible maximum. My speedo ranges to 150MPH.

I wonder if for both the pipe thermometer and a car speedo, the gauge is
calibrated beyond what is ever achievable because the gauge becomes less
accurate as it reaches full-scale deflection and so they arrange that the
highest achievable is some way short of FSD. Only a theory - and I'm
probably wrong.

Even if water at 3 bar would boil at 120 degC, I doubt whether anyone would
set their boiler for that sort of temperature (60 is more typicial) because
any contact with a pipe at 120 would cause a nasty burn. I've always
wondered why it is that 50 degC shade temperature (eg in Death Valley) is
something that the human body cannot tolerate for more than a few minutes,
and yet saunas can (apparently) have a room temperature of almost 100 degC.
I know saunas are very dry heat but so is Death Valley.

On 14/11/2020 22:04, Tim+ wrote:
newshound wrote:
On 14/11/2020 20:14, Tim+ wrote:
michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may cause
the problem

So youre taking the calibrated scale of a thermometer as an indication of
typical CH water temperatures?

Tim

Boiling point of water at 3 bar is about 134 deg C. IIRC boiler gauges
typically go to 3 bar, presumably relief valves are slightly less.


So youre taking the relief pressure valve setting in boilers as an
indication of typical CH water temperature?

Tim

Of course not. I am pointing out that, potentially, that's the
temperature the water could reach if there was a double failure in the
boiler control system.

I'm also making the point that it is not *so* unreasonable to have a
pipework thermometer capable of going up to 120 deg C.

newshound wrote:
On 14/11/2020 22:04, Tim+ wrote:
newshound wrote:
On 14/11/2020 20:14, Tim+ wrote:
michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may cause
the problem

So youre taking the calibrated scale of a thermometer as an indication of
typical CH water temperatures?

Tim

Boiling point of water at 3 bar is about 134 deg C. IIRC boiler gauges
typically go to 3 bar, presumably relief valves are slightly less.


So youre taking the relief pressure valve setting in boilers as an
indication of typical CH water temperature?

Tim

Of course not. I am pointing out that, potentially, that's the
temperature the water could reach if there was a double failure in the
boiler control system.

I'm also making the point that it is not *so* unreasonable to have a
pipework thermometer capable of going up to 120 deg C.


I never said it wasnt. Just pointing out that just because a pipe
thermometer reads up to 120, its in no way a typical CH pipe temperature.

Tim

--
Please don't feed the trolls

On 14/11/2020 17:21, soup wrote:

Not a want as such just put my mind at ease.

I spent today running co-ax cable from the loft to run the telly free view.
This co-ax/freeview is emergency back up for if the Fire TV stick
/internet fails
So fire stick fall back to Freeview because I got ****ed of paying
Virgin[1] to watch ads.

I was fairly careful when I was running the co-ax down various 'holes'
not to touch pipework, I am worried though that the cable may move and
touch the pipework .
Will the co-ax cope with touching domestic hot water pipes or will this
heat load cause the cable insulation to degrade or off-gas?

IMHO it will be fine.

Typically PVC clad cables are specified for a maximum continuos
conductor[1] temperature of 70 deg C. Beyond that, you may start to see
some gradual degradation of the plastic - (typically it becoming more
brittle as it loses plasticiser) - but at only a little over than you
can expect it to take decades.

A CH pipe will probably be less than 70 degrees anyway, and even if not
it will not be continuously at that temp.

[1] The outer sheath will usually be at least as good as the insulation
on the conductors.

--
Cheers,

John.

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

On 14/11/2020 20:28, newshound wrote:
On 14/11/2020 20:14, Tim+ wrote:
michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may
cause
the problem

So youre taking the calibrated scale of a thermometer as an
indication of
typical CH water temperatures?

Tim

Boiling point of water at 3 bar is about 134 deg C. IIRC boiler gauges
typically go to 3 bar, presumably relief valves are slightly less.

The PRV is normally just that, not an Over Temp & Pressure Release
Valve. However the bailer's main internal stat will typically kick in
well before boiling point.

(and remember the flue on most modern boilers has a plastic inner!)

--
Cheers,

John.

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

On 14/11/2020 21:54, michael adams wrote:
Harry Bloomfield; "Esq." wrote in message
...
michael adams presented the following explanation :
Er, no ? As I said above, it's the pipes themselves which are 120C, it being
a pipe thermometer, after all. Not necessarily a CH water thermometer, at
least as far as I know.

..and how might the pipe be hotter than the water in contains?

That is indeed the question. But the fact remains that the thermometer
does go up to 120C.

It's no like a car where they may fit an over-optimistic speedometer
that far exceeds any possible speed of the car, which the driver
could never legally attain in most jurisdictions in any case.

So why up to 120C ?

Just because an Amazon seller calls it a "Clip On Hot Water Pipe
Thermometer", does not mean it was *designed* only for hot water pipes.

It might find service on steam pipe or oil pipe.

(and the thermometer is not going to know or care what is in the pipe!)


--
Cheers,

John.

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

On 14/11/2020 19:44, michael adams wrote:
Clip On Hot Water Pipe Thermometer 0-120C 63MM Temperature Gauge

https://www.amazon.co.uk/Thermometer.../dp/B01N8SQS54

Which goes up to 120C Which suggests the pipes themselves can exceed
the temperature of boiling water which is 100C. Most other pipe
thermometers seem to go to 120C as well. Not that I'd claim to
understand how this makes any sense.

Possibly it's intended to cope with pressurised steam pipes. They really
burn if you touch them. Or it might be a basic design also used for
other products, such as asphalt thermometers.

Bill

On 14/11/2020 20:54, michael adams wrote:
But if you clip it on to a CH pipe or domestic hot water pipe the reading will be
around 70C.
I'm quite prepared to believe you. But then why have thermometers that go up to 120C
if there's no need ?

What does it matter? What does it ****ing matter?

I'll expand on what I said before. I started installing TV aerials as a
full time job in 1971, after working part time for five years. Over the
following five decades my business expanded to include domestic and
commercial satellite reception, CCTV, private mobile radio, broadcast
radio transmission aerials, and very large RF distribution systems. In
all that time, with that wealth of practical experience, I never once,
never ever, not once, ever, encountered a length of coax that had been
adversely affected by being in contact with a hot pipe. So does that put
your mind at rest?

Bill

On 14/11/2020 19:44, michael adams wrote:
Polyethylene and polyvinyl chloride are used as insulators. These two
plastics have relatively low melting points, and can start to soften at
temperatures as low as 150 degrees F. [65 C]

Yes, coax becomes more flexible on hot days, and can be a stiff
nightmare in winter.

If the insulation is exposed to low heat over long periods of time, the
position of the center conductor in relation to the shielding may shift
as the hot plastics yield. If the center conductor and shielding
touch, signal never makes it past that point. Coax should be kept away
from heatsinks, stage lights, and other sources of heat

But my goodness it would have to get damned hot to let the inner
migrate. It would be easy enough to test. Put some coax into a tight
bend and boil it in water for a few hours. I've never done this, but I
can tell you that black coax on a south facing wall on a hot day gets
too hot to touch (I've been burnt) and yet it continues to work.

Bill

On 14/11/2020 20:14, Tim+ wrote:
michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may cause
the problem

So youre taking the calibrated scale of a thermometer as an indication of
typical CH water temperatures?

Tim

The heat cannot be 'radiated at 120C' whatever that means, when the
water temperature never exceeds 60 °C.

Someone should to a study on the correlation between Left thinking and
inability to understand any science at all.

--
There is nothing a fleet of dispatchable nuclear power plants cannot do
that cannot be done worse and more expensively and with higher carbon
emissions and more adverse environmental impact by adding intermittent
renewable energy.

On 14/11/2020 20:28, newshound wrote:
On 14/11/2020 20:14, Tim+ wrote:
michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may
cause
the problem

So youre taking the calibrated scale of a thermometer as an
indication of
typical CH water temperatures?

Tim

Boiling point of water at 3 bar is about 134 deg C. IIRC boiler gauges
typically go to 3 bar, presumably relief valves are slightly less.

So what? No CH boiler ever 'boils' water in the CH
pipes.

--
There is nothing a fleet of dispatchable nuclear power plants cannot do
that cannot be done worse and more expensively and with higher carbon
emissions and more adverse environmental impact by adding intermittent
renewable energy.

On 14/11/2020 22:04, Tim+ wrote:
newshound wrote:
On 14/11/2020 20:14, Tim+ wrote:
michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may cause
the problem

So youre taking the calibrated scale of a thermometer as an indication of
typical CH water temperatures?

Tim

Boiling point of water at 3 bar is about 134 deg C. IIRC boiler gauges
typically go to 3 bar, presumably relief valves are slightly less.


So youre taking the relief pressure valve setting in boilers as an
indication of typical CH water temperature?

Tim

It's another Left mind. Mired in its own bull****

--
There is nothing a fleet of dispatchable nuclear power plants cannot do
that cannot be done worse and more expensively and with higher carbon
emissions and more adverse environmental impact by adding intermittent
renewable energy.

On Sat, 14 Nov 2020 18:08:53 +0000, Andrew wrote:

On 14/11/2020 17:32, Jack Harry Teesdale wrote:
On 14/11/2020 17:21, soup wrote:
Not a want as such just put my mind at ease.

I spent today running co-ax cable from the loft to run the telly free
view.
This co-ax/freeview is emergency back up for if the Fire TV stick
/internet fails
So fire stick fall back to Freeview because I got ****ed of paying
Virgin[1] to watch ads.

I was fairly careful when I was running the co-ax down various 'holes'
not to touch pipework, I am worried though that the cable may move and
touch the pipework .
Will the co-ax cope with touching domestic hot water pipes or will
this heat load cause the cable insulation to degrade or off-gas?

[1] Have decided to ditch Virgin altogether (had phone,TV and internet
from them).* And move to Vodaphone. They have installed gigafast cable
to here (Balerno outskirts of Edinburgh[one of only 15 cities to get
gigafast]) so getting internet from them, they 'throw' in a phone line .
TV as 'said' Firestick with freeview backup.

It is not a good idea to have pvc insulation in permanant contact with
central heating hot water pipes. Could you not use clips to secure the
coax away from the pipes?

Why not ?. It survives UV light out of doors.

At what temperature would a pipe radiate UV?
--
Peter.
The gods will stay away
whilst religions hold sway