Yesterday arrived home from holiday to hear a strange thrumming noise
under the breakfast room floor, with signs of damp. Lifted the
floorboard and found the mains water supply pipe, in which was fitted an
ugly round metal object labelled Dereve Water Governor. This thing had a
little bleed hole in the top from which water was squirting upwards at
high speed, soaking the floorboards and joists.

On consulting Google it appears that the thing has an internal diaphragm
that has probably split, hence the jet of water gradually destroying my
house.

OK, things fail, and usually they can be fixed or replaced. But why
would someone design a piece of equipment that is bound, eventually, to
fail in such a catastrophic manner?

--
Jack

"Handsome Jack" wrote in message
...
Yesterday arrived home from holiday to hear a strange thrumming noise
under the breakfast room floor, with signs of damp. Lifted the floorboard
and found the mains water supply pipe, in which was fitted an ugly round
metal object labelled Dereve Water Governor. This thing had a little bleed
hole in the top from which water was squirting upwards at high speed,
soaking the floorboards and joists.

On consulting Google it appears that the thing has an internal diaphragm
that has probably split, hence the jet of water gradually destroying my
house.

OK, things fail, and usually they can be fixed or replaced. But why would
someone design a piece of equipment that is bound, eventually, to fail in
such a catastrophic manner?

Because it costs more to do it better.

On Thursday, 6 September 2018 21:57:26 UTC+1, Handsome Jack wrote:
Yesterday arrived home from holiday to hear a strange thrumming noise
under the breakfast room floor, with signs of damp. Lifted the
floorboard and found the mains water supply pipe, in which was fitted an
ugly round metal object labelled Dereve Water Governor. This thing had a
little bleed hole in the top from which water was squirting upwards at
high speed, soaking the floorboards and joists.

On consulting Google it appears that the thing has an internal diaphragm
that has probably split, hence the jet of water gradually destroying my
house.

OK, things fail, and usually they can be fixed or replaced. But why
would someone design a piece of equipment that is bound, eventually, to
fail in such a catastrophic manner?

because they want you to tell everyone and drive them out of business.

Yes indeed, I think we have forgotten long term testing as most stuff if it
lasts five years may last a lot longer but I suppose if you were going to
fit such a thing inside a nuclear reactor you would bloody well life test
it, but for domestic use, nah, nobody bothers any more, its like washing
machine hoses that go hard and split.
I do feel however that a failure mode should not be to flood ones house
without some kind of way to stop it!
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.!
"Josh Nack" wrote in message
...


"Handsome Jack" wrote in message
...
Yesterday arrived home from holiday to hear a strange thrumming noise
under the breakfast room floor, with signs of damp. Lifted the floorboard
and found the mains water supply pipe, in which was fitted an ugly round
metal object labelled Dereve Water Governor. This thing had a little
bleed hole in the top from which water was squirting upwards at high
speed, soaking the floorboards and joists.

On consulting Google it appears that the thing has an internal diaphragm
that has probably split, hence the jet of water gradually destroying my
house.

OK, things fail, and usually they can be fixed or replaced. But why would
someone design a piece of equipment that is bound, eventually, to fail in
such a catastrophic manner?

Because it costs more to do it better.

You cynic. Whatever the pros and cons of the original post. I can think of
lots of devices where failure modes are not considered and which if they
happen can be very damaging or dangerous.
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.!
wrote in message
...
On Thursday, 6 September 2018 21:57:26 UTC+1, Handsome Jack wrote:
Yesterday arrived home from holiday to hear a strange thrumming noise
under the breakfast room floor, with signs of damp. Lifted the
floorboard and found the mains water supply pipe, in which was fitted an
ugly round metal object labelled Dereve Water Governor. This thing had a
little bleed hole in the top from which water was squirting upwards at
high speed, soaking the floorboards and joists.

On consulting Google it appears that the thing has an internal diaphragm
that has probably split, hence the jet of water gradually destroying my
house.

OK, things fail, and usually they can be fixed or replaced. But why
would someone design a piece of equipment that is bound, eventually, to
fail in such a catastrophic manner?

because they want you to tell everyone and drive them out of business.

Brian Gaff posted
You cynic. Whatever the pros and cons of the original post. I can think of
lots of devices where failure modes are not considered and which if they
happen can be very damaging or dangerous.

That's really the point of my OP. What other examples are there? I
couldn't easily think of any in the household context.

--
Jack

On 07/09/18 09:03, Handsome Jack wrote:
Brian Gaff posted
You cynic. Whatever the pros and cons of the original post. I can
think of
lots of devices where failure modes are not considered and which if they
happen can be very damaging or dangerous.

That's really the point of my OP. What other examples are there? I
couldn't easily think of any in the household context.

Well. I just replaced the 18 year old fan in a downstairs toilet by
removing half the ceiling and refitting platerboard, reskimming and
repaining.

That should see me out.
..
Thers a 12V transformer buried in a wall as well. That hasnt failed
after 18 years

Thers a whole lot of mains cable buried in walls along with cat V
cxable, and of course plumbing. That lot hasnt failed ither.

In fact there is insulation buried in the walls., That hasn't failed too.

And underfloor pipes in te screed.

In short the answer to your question is that sometimes the likelihood of
failure is so low and the cost of fixing it only moderate, that its not
worth naking easy access.

Bit like changing the timing belt on some cars. There you are at 100,000
miles/10 years faced with £1000 to change the cambelt. A process that
requires so much car dimsnantling that you might as well change ALL the
other belts and the water pump at the same time, whether they need it or
not...:-)

Oh for the days of vast engine bays...






--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

On 07/09/2018 09:50, The Natural Philosopher wrote:

Bit like changing the timing belt on some cars. There you are at 100,000
miles/10 years faced with £1000 to change the cambelt. A process that
requires so much car dimsnantling that you might as well change ALL the
other belts and the water pump at the same time, whether they need it or
not...:-)

I just played that game in reverse - the water pump was leaking, so
since that involved removal of lots of stuff including the cam belt
(from which it is driven), There was no point in them not doing that and
all the other belts in the vicinity while they were at it.

Daylight rubbery you might call it ;-)

Oh for the days of vast engine bays...

I had enough trouble just getting my arm in there with a camera to try
and work out what was leaking!

--
Cheers,

John.

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

On Friday, 7 September 2018 09:09:58 UTC+1, Handsome Jack wrote:
Brian Gaff posted

You cynic. Whatever the pros and cons of the original post. I can think of
lots of devices where failure modes are not considered and which if they
happen can be very damaging or dangerous.

That's really the point of my OP. What other examples are there? I
couldn't easily think of any in the household context.

if single realistic faults cause danger then they're not fit for sale, at least for electrical goods. IME though people often fail to appreciate many of the protection mechanisms that are used (in electrical products).


NT

On 07/09/2018 10:48, John Rumm wrote:
On 07/09/2018 09:50, The Natural Philosopher wrote:

Bit like changing the timing belt on some cars. There you are at
100,000 miles/10 years faced with £1000 to change the cambelt. A
process that requires so much car dimsnantling that you might as well
change ALL the other belts and the water pump at the same time,
whether they need it or not...:-)

I just played that game inÂ* reverse - the water pump was leaking, so
since that involved removal of lots of stuff including the cam belt
(from which it is driven), There was no point in them not doing that and
all the other belts in the vicinity while they were at it.

Daylight rubbery you might call it ;-)

Oh for the days of vast engine bays...

I had enough trouble just getting my arm in there with a camera to try
and work out what was leaking!

This is what mechanics are for :-)

On 07/09/2018 21:52, newshound wrote:
On 07/09/2018 10:48, John Rumm wrote:
On 07/09/2018 09:50, The Natural Philosopher wrote:

Bit like changing the timing belt on some cars. There you are at
100,000 miles/10 years faced with £1000 to change the cambelt. A
process that requires so much car dimsnantling that you might as well
change ALL the other belts and the water pump at the same time,
whether they need it or not...:-)

I just played that game inÂ* reverse - the water pump was leaking, so
since that involved removal of lots of stuff including the cam belt
(from which it is driven), There was no point in them not doing that
and all the other belts in the vicinity while they were at it.

Daylight rubbery you might call it ;-)

Oh for the days of vast engine bays...

I had enough trouble just getting my arm in there with a camera to try
and work out what was leaking!

This is what mechanics are for :-)

I should say that I am lucky, not only because I can now easily afford
to pay someone, but also because my mechanic is even more nerdy and
obsessive than me.

On Thursday, 6 September 2018 21:57:26 UTC+1, Handsome Jack wrote:
Yesterday arrived home from holiday to hear a strange thrumming noise
under the breakfast room floor, with signs of damp. Lifted the
floorboard and found the mains water supply pipe, in which was fitted an
ugly round metal object labelled Dereve Water Governor. This thing had a
little bleed hole in the top from which water was squirting upwards at
high speed, soaking the floorboards and joists.

On consulting Google it appears that the thing has an internal diaphragm
that has probably split, hence the jet of water gradually destroying my
house.

OK, things fail, and usually they can be fixed or replaced. But why
would someone design a piece of equipment that is bound, eventually, to
fail in such a catastrophic manner?

--
Jack

In industrial situations there is a pressure relief valve fitted with the outlet going somewhere safe.
I assume there's none fitted to save money.
Most water PRVs are piston operated (ie no diaphragm)
But prone to sticking. Esp. in hard water areas.

On 07/09/2018 21:54, newshound wrote:
On 07/09/2018 21:52, newshound wrote:
On 07/09/2018 10:48, John Rumm wrote:
On 07/09/2018 09:50, The Natural Philosopher wrote:

Bit like changing the timing belt on some cars. There you are at
100,000 miles/10 years faced with £1000 to change the cambelt. A
process that requires so much car dimsnantling that you might as
well change ALL the other belts and the water pump at the same time,
whether they need it or not...:-)

I just played that game inÂ* reverse - the water pump was leaking, so
since that involved removal of lots of stuff including the cam belt
(from which it is driven), There was no point in them not doing that
and all the other belts in the vicinity while they were at it.

Daylight rubbery you might call it ;-)

Oh for the days of vast engine bays...

I had enough trouble just getting my arm in there with a camera to
try and work out what was leaking!

This is what mechanics are for :-)

I should say that I am lucky, not only because I can now easily afford
to pay someone, but also because my mechanic is even more nerdy and
obsessive than me.

In spite of my usual MO of DIYing pretty much anything, I don't do cars
generally.

However I did want to know roughly what was leaking so I could assess
the probability of unexpected failure, since the car was booked in a few
days hence and I needed to go places.

If it was a leaking rad or hose, then I would not have risked it since
the possibility of total failure would have been high. However since it
looked like it was just a to occasional drip from the pump that was
landing on the hot exhaust manifold, I figured it would limp on ok for a
couple of shortish journeys.


--
Cheers,

John.

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

On 08/09/2018 08:52, harry wrote:
On Thursday, 6 September 2018 21:57:26 UTC+1, Handsome Jack wrote:
Yesterday arrived home from holiday to hear a strange thrumming noise
under the breakfast room floor, with signs of damp. Lifted the
floorboard and found the mains water supply pipe, in which was fitted an
ugly round metal object labelled Dereve Water Governor. This thing had a
little bleed hole in the top from which water was squirting upwards at
high speed, soaking the floorboards and joists.

On consulting Google it appears that the thing has an internal diaphragm
that has probably split, hence the jet of water gradually destroying my
house.

OK, things fail, and usually they can be fixed or replaced. But why
would someone design a piece of equipment that is bound, eventually, to
fail in such a catastrophic manner?

--
Jack

In industrial situations there is a pressure relief valve fitted with the outlet going somewhere safe.
I assume there's none fitted to save money.
Most water PRVs are piston operated (ie no diaphragm)
But prone to sticking. Esp. in hard water areas.

They are not usually fitted to save money in domestic situations either.
They are normally there to either reduce water hammer and pipe noise,
plus make life a bit easier for taps, or sometimes to provide a pressure
balance for a shower etc.


--
Cheers,

John.

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

On 10/09/2018 18:19, John Rumm wrote:
On 08/09/2018 08:52, harry wrote:
On Thursday, 6 September 2018 21:57:26 UTC+1, Handsome JackÂ* wrote:
Yesterday arrived home from holiday to hear a strange thrumming noise
under the breakfast room floor, with signs of damp. Lifted the
floorboard and found the mains water supply pipe, in which was fitted an
ugly round metal object labelled Dereve Water Governor. This thing had a
little bleed hole in the top from which water was squirting upwards at
high speed, soaking the floorboards and joists.

On consulting Google it appears that the thing has an internal diaphragm
that has probably split, hence the jet of water gradually destroying my
house.

OK, things fail, and usually they can be fixed or replaced. But why
would someone design a piece of equipment that is bound, eventually, to
fail in such a catastrophic manner?

--
Jack

In industrial situations there is a pressure relief valve fitted with
the outlet going somewhere safe.
I assume there's none fitted to save money.
Most water PRVs are piston operated (ie no diaphragm)
But prone to sticking. Esp. in hard water areas.

They are not usually fitted to save money in domestic situations either.
They are normally there to either reduce water hammer and pipe noise,
plus make life a bit easier for taps, or sometimes to provide a pressure
balance for a shower etc.


I'd say pressure relief valves are almost always fitted to prevent
overpressure, and often with some sort of "safe" outlet. Water hammer
etc. is normally dealt with using something like an accumulator.

This failed item is a pressure regulator, used where mains pressure is
(or can be) high to make life easier for all the various domestic valves
and taps.

On 10/09/2018 20:04, newshound wrote:
On 10/09/2018 18:19, John Rumm wrote:
On 08/09/2018 08:52, harry wrote:
On Thursday, 6 September 2018 21:57:26 UTC+1, Handsome JackÂ* wrote:
Yesterday arrived home from holiday to hear a strange thrumming noise
under the breakfast room floor, with signs of damp. Lifted the
floorboard and found the mains water supply pipe, in which was
fitted an
ugly round metal object labelled Dereve Water Governor. This thing
had a
little bleed hole in the top from which water was squirting upwards at
high speed, soaking the floorboards and joists.

On consulting Google it appears that the thing has an internal
diaphragm
that has probably split, hence the jet of water gradually destroying my
house.

OK, things fail, and usually they can be fixed or replaced. But why
would someone design a piece of equipment that is bound, eventually, to
fail in such a catastrophic manner?

--
Jack

In industrial situations there is a pressure relief valve fitted with
the outlet going somewhere safe.
I assume there's none fitted to save money.
Most water PRVs are piston operated (ie no diaphragm)
But prone to sticking. Esp. in hard water areas.

They are not usually fitted to save money in domestic situations
either. They are normally there to either reduce water hammer and pipe
noise, plus make life a bit easier for taps, or sometimes to provide a
pressure balance for a shower etc.


I'd say pressure relief valves are almost always fitted to prevent

Note I am talking about a Pressure Reduction/Regulation Valve, not a
relief valve. Apologies for the confusion - I had not noticed harry had
wandered off at a tangent as usual!

i.e. as in the bottom right of :

http://wiki.diyfaq.org.uk/index.php/...erBagpipes.png

overpressure, and often with some sort of "safe" outlet. Water hammer
etc. is normally dealt with using something like an accumulator.

This failed item is a pressure regulator, used where mains pressure is
(or can be) high to make life easier for all the various domestic valves
and taps.

yup.


--
Cheers,

John.

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

On 10/09/2018 20:40, John Rumm wrote:
On 10/09/2018 20:04, newshound wrote:
O

Note I am talking about a Pressure Reduction/Regulation Valve, not a
relief valve. Apologies for the confusion - I had not noticed harry had
wandered off at a tangent as usual!

:-)


i.e. as in the bottom right of :

http://wiki.diyfaq.org.uk/index.php/...erBagpipes.png

Knitted copper bagpipes! I love it!