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Date: 28 Dec 2006 09:28:19
From: daveb
Subject: Imagine the force of the explosion
in an HX machine:
if the pressurestat were to stick closed (a frequent occurrence)

AND

the safety valve were to fail shut. (fairly rare)

ouch.

Dave
www.hitechespresso.com





 
Date: 21 Jan 2007 16:17:46
From: daveb
Subject: Re: Imagine the force of the explosion
oops!

pardon my ethnocentricity!

dave

Brent wrote:
> your space program, all we have here is "open spaces"
>
> :)
>
> Brent
>
> > one need look no further than our 'space program'
> >
> > dave
> > Brent wrote:
> >> > in an HX machine:
> >> > if the pressurestat were to stick closed (a frequent occurrence)
> >> >
> >> > AND
> >> >
> >> > the safety valve were to fail shut. (fairly rare)
> >> >
> >> > ouch.
> >> >
> >> > Dave
> >>
> >> I was talking to a tech who had seen a multiple failure of protection
> >> systems. Apparently the only reason the machine didn't go further was the
> >> water line. The porcelin cups made a nice scatter pattern on the
> >> ceiling...
> >>
> >> Equally, I have an old friend who watched three robust critical safety
> >> devices fail, and two of his colleagues killed as a result while he
> >> watched.
> >> Until that point it was considered that the three safety system was going
> >> overboard on safety, as the first safety device didn't fail.
> >>
> >> Safety systems do fail in sequence.
> >>
> >> Brent
> >



  
Date: 22 Jan 2007 14:02:43
From: Brent
Subject: Re: Imagine the force of the explosion
But then again, isn't the moon in the Australian outback, which makes me
closer to the moon than you :)

Brent

> oops!
>
> pardon my ethnocentricity!
>
> dave
>
> Brent wrote:
>> your space program, all we have here is "open spaces"
>>
>> :)
>>
>> Brent
>>
>> > one need look no further than our 'space program'
>> >
>> > dave
>> > Brent wrote:
>> >> > in an HX machine:
>> >> > if the pressurestat were to stick closed (a frequent occurrence)
>> >> >
>> >> > AND
>> >> >
>> >> > the safety valve were to fail shut. (fairly rare)
>> >> >
>> >> > ouch.
>> >> >
>> >> > Dave
>> >>
>> >> I was talking to a tech who had seen a multiple failure of protection
>> >> systems. Apparently the only reason the machine didn't go further was
>> >> the
>> >> water line. The porcelin cups made a nice scatter pattern on the
>> >> ceiling...
>> >>
>> >> Equally, I have an old friend who watched three robust critical safety
>> >> devices fail, and two of his colleagues killed as a result while he
>> >> watched.
>> >> Until that point it was considered that the three safety system was
>> >> going
>> >> overboard on safety, as the first safety device didn't fail.
>> >>
>> >> Safety systems do fail in sequence.
>> >>
>> >> Brent
>> >
>




 
Date: 21 Jan 2007 15:05:21
From: daveb
Subject: Re: Imagine the force of the explosion
one need look no further than our 'space program'

dave
Brent wrote:
> > in an HX machine:
> > if the pressurestat were to stick closed (a frequent occurrence)
> >
> > AND
> >
> > the safety valve were to fail shut. (fairly rare)
> >
> > ouch.
> >
> > Dave
>
> I was talking to a tech who had seen a multiple failure of protection
> systems. Apparently the only reason the machine didn't go further was the
> water line. The porcelin cups made a nice scatter pattern on the ceiling...
>
> Equally, I have an old friend who watched three robust critical safety
> devices fail, and two of his colleagues killed as a result while he watched.
> Until that point it was considered that the three safety system was going
> overboard on safety, as the first safety device didn't fail.
>
> Safety systems do fail in sequence.
>
> Brent



  
Date: 22 Jan 2007 12:50:22
From: Brent
Subject: Re: Imagine the force of the explosion
your space program, all we have here is "open spaces"

:)

Brent

> one need look no further than our 'space program'
>
> dave
> Brent wrote:
>> > in an HX machine:
>> > if the pressurestat were to stick closed (a frequent occurrence)
>> >
>> > AND
>> >
>> > the safety valve were to fail shut. (fairly rare)
>> >
>> > ouch.
>> >
>> > Dave
>>
>> I was talking to a tech who had seen a multiple failure of protection
>> systems. Apparently the only reason the machine didn't go further was the
>> water line. The porcelin cups made a nice scatter pattern on the
>> ceiling...
>>
>> Equally, I have an old friend who watched three robust critical safety
>> devices fail, and two of his colleagues killed as a result while he
>> watched.
>> Until that point it was considered that the three safety system was going
>> overboard on safety, as the first safety device didn't fail.
>>
>> Safety systems do fail in sequence.
>>
>> Brent
>




 
Date: 22 Jan 2007 11:25:32
From: Brent
Subject: Re: Imagine the force of the explosion
> in an HX machine:
> if the pressurestat were to stick closed (a frequent occurrence)
>
> AND
>
> the safety valve were to fail shut. (fairly rare)
>
> ouch.
>
> Dave

I was talking to a tech who had seen a multiple failure of protection
systems. Apparently the only reason the machine didn't go further was the
water line. The porcelin cups made a nice scatter pattern on the ceiling...

Equally, I have an old friend who watched three robust critical safety
devices fail, and two of his colleagues killed as a result while he watched.
Until that point it was considered that the three safety system was going
overboard on safety, as the first safety device didn't fail.

Safety systems do fail in sequence.

Brent




 
Date: 17 Jan 2007 16:48:40
From: daveb
Subject: Re: Imagine the force of the explosion
we all must defend our logic for ownership of any given piece of stuff.

Dave



 
Date: 29 Dec 2006 16:58:32
From: daveb
Subject: Re: Imagine the force of the explosion
granted that it would be a rare occurence.

But think of the mess, if the relief valve had been blowing ALL DAY
"whilst" one is at work, and the machine was -- or was not -- plumbed
to the water supply.
what about the damage to the machine internals? brain box? level
control, wiring?

my, my.

Joe has a great point a secondary electrical cutout should always be
provided, but probably would NOT trip until all the water is consumed.

Dave



  
Date: 17 Jan 2007 23:41:09
From: Karl Denninger
Subject: Re: Imagine the force of the explosion

In article <1167440312.075278.324030@k21g2000cwa.googlegroups.com >,
daveb <davebobblane@gmail.com > wrote:
>
>
>granted that it would be a rare occurence.
>
>But think of the mess, if the relief valve had been blowing ALL DAY
>"whilst" one is at work, and the machine was -- or was not -- plumbed
>to the water supply.
>what about the damage to the machine internals? brain box? level
>control, wiring?
>
>my, my.
>
>Joe has a great point a secondary electrical cutout should always be
>provided, but probably would NOT trip until all the water is consumed.
>
>Dave

As a point of order, all machines I've seen have a safety cutout (some
resettable, some not) for overtemp in the boiler.

BTW, SSRs usually fail closed. Mechanical switches (e.g. pressurstats) can
and do fail either way.

--
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net My home on the net - links to everything I do!
http://scubaforum.org Your UNCENSORED place to talk about DIVING!
http://genesis3.blogspot.com Musings Of A Sentient Mind


 
Date: 28 Dec 2006 13:22:09
From: JoeP
Subject: Re: Imagine the force of the explosion

daveb wrote:
> in an HX machine:
> if the pressurestat were to stick closed (a frequent occurrence)
>
> AND
>
> the safety valve were to fail shut. (fairly rare)
>
> ouch.
>
> Dave
> www.hitechespresso.com

Hmm.......Why some people leave their machine on in their home all day
is very odd to me. I turn my machine on let it warm up pull a few shots
usually and clean it and turn it back off. I have heard of fires
happening with espresso machies when water leakage sparked the
electronics. But I would think there would be a lot of noise going on
prior to an explosion. I know there is usually some expanding and
contracting noises that are normal and I would suspect there would be
even more that would cause concern.

Joe
www.greencoffeebuyingclub.com
"freinds getting together splitting bags of coffee"



  
Date: 29 Dec 2006 18:15:12
From: Danny
Subject: Re: Imagine the force of the explosion
JoeP wrote:

> Hmm.......Why some people leave their machine on in their home all day
> is very odd to me. I turn my machine on let it warm up pull a few shots
> usually and clean it and turn it back off. I have heard of fires
> happening with espresso machies when water leakage sparked the
> electronics. But I would think there would be a lot of noise going on
> prior to an explosion. I know there is usually some expanding and
> contracting noises that are normal and I would suspect there would be
> even more that would cause concern.
>

Just some scaremongering. Of course, any mechanical or electrical
item can fail, but we still leave TV's etc in standby mode. My 3
group Gaggia lever machine (circa 25 years old or more) has been left
on for nearly five years. The pressurestat showed me it's intentions
to quit far before it would actually die (by having a wider deadband)
and I promptly remedied the fault. Boilers don't suddenly explode,
although they may develop slow leaks (but these usually scale up
anyway), or the autofill could fail in the "on" position, but I've not
encountered any such horrors. The two group in the trailer is on for
at least 14 hours a day, and often for a week or more if frost is
expected overnight.

These are commercial machines that are designed this way, domestic
machines may not have the same MTBF rates.


--
Regards, Danny

http://www.gaggia-espresso.com (a purely hobby site)
http://www.malabargold.co.uk (UK/EU ordering for Malabar Gold blend)



   
Date: 29 Dec 2006 16:46:40
From: Ken Fox
Subject: Re: Imagine the force of the explosion
"Danny" <danny@nospam.gaggia-espresso.com > wrote in message
news:4vl47jF1c63rjU1@mid.individual.net...
>>
> Just some scaremongering. Of course, any mechanical or electrical item
> can fail, but we still leave TV's etc in standby mode. My 3 group Gaggia
> lever machine (circa 25 years old or more) has been left on for nearly
> five years. The pressurestat showed me it's intentions to quit far before
> it would actually die (by having a wider deadband) and I promptly remedied
> the fault. Boilers don't suddenly explode, although they may develop slow
> leaks (but these usually scale up anyway), or the autofill could fail in
> the "on" position, but I've not encountered any such horrors. The two
> group in the trailer is on for at least 14 hours a day, and often for a
> week or more if frost is expected overnight.
>
> These are commercial machines that are designed this way, domestic
> machines may not have the same MTBF rates.
>

I assure you that someday you will regret this. Within the next two
centuries, you will experience a failure at 2 in the morning, and if you had
never bought or used an espresso machine, you would have been spared.

ken
;-)




    
Date: 30 Dec 2006 08:36:48
From: Danny
Subject: Re: Imagine the force of the explosion
Ken Fox wrote:

> I assure you that someday you will regret this. Within the next two
> centuries, you will experience a failure at 2 in the morning, and if you had
> never bought or used an espresso machine, you would have been spared.
>
> ken
> ;-)

I once phoned the electricity company to complain that I hadn't ever
had a meaningful power cut, even though the supply was actually
guaranteed to exceed 99.2% or other such number. I remonstrated that
since I have a house full of tilley and aladdin lamps etc, open coal
fires, many primus and other stoves and a big UPS for the PC, I wanted
my share of power cuts - at least one that lasted a night, so I could
play with my stuff. I could still run the trailer as well and pull
shots :)


--
Regards, Danny

http://www.gaggia-espresso.com (a purely hobby site)
http://www.malabargold.co.uk (UK/EU ordering for Malabar Gold blend)



 
Date: 28 Dec 2006 20:29:04
From: Barry Jarrett
Subject: Re: Imagine the force of the explosion
On 28 Dec 2006 09:28:19 -0800, "daveb" <davebobblane@gmail.com > wrote:

>in an HX machine:
>if the pressurestat were to stick closed (a frequent occurrence)
>

or the SSR were to fail 'on'.



  
Date: 28 Dec 2006 16:38:07
From: sprsso
Subject: Re: Imagine the force of the explosion
I hear that....al


On Thu, 28 Dec 2006 20:29:04 GMT, Barry Jarrett
<barry@rileys-coffee.com > wrote:

>On 28 Dec 2006 09:28:19 -0800, "daveb" <davebobblane@gmail.com> wrote:
>
> >in an HX machine:
> >if the pressurestat were to stick closed (a frequent occurrence)
> >
>
>or the SSR were to fail 'on'.



 
Date: 28 Dec 2006 11:05:56
From:
Subject: Re: Imagine the force of the explosion
You still better have the thermal safety switches there as another
shutdown backup



 
Date: 28 Dec 2006 12:59:07
From: jim schulman
Subject: Re: Imagine the force of the explosion
On 28 Dec 2006 09:28:19 -0800, "daveb" <davebobblane@gmail.com > wrote:

>in an HX machine:
>if the pressurestat were to stick closed (a frequent occurrence)
>
>AND
>
>the safety valve were to fail shut. (fairly rare)
>
>ouch.

Presumably, the gaskets would all start leaking before anything blew
up.