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uk.rec.cars.fuel.lpg (Cars Running LPG) (uk.rec.cars.fuel.lpg)

LPG leak.



 
 
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  #1 (permalink)  
Old July 3rd 03, 07:34 PM posted to uk.rec.cars.fuel.lpg
richt
external usenet poster
 
Posts: 4
Default LPG leak.

Please excuse the long and winding post I will get to the point.

I have a Mercedes V-Class 280 with a BRC LPG conversion. I am sorry but I do
not know how the system is setup.

I am currently in distpute with the dealer I bought the car off. He is
saying there is a LPG leak on the vehicle and I do not believe them.

I took the car back to them to sort out a few minor problems and to
investigate/remove the smell of petrol. I was told the minor problems had
been sorted and that the car had been sent to the conversion fitters to sort
the LPG leak out. When I enquired what LPG leak I was told the one the
dealer found after the petrol leak was fixed.

That was very strange because I had never smelt LPG in the vehicle. I had
deliberatly run the car on minimal petrol in the tank because it removed the
smell of petrol. So ran almost exclusively on LPG as would be the norm.

When I spoke to the LPG installers they said they had found a petrol leak
near the the petrol filler to petrol tank joint. This marries up with what I
had reported to the dealer but not told the LPG installers. They also said
that there had never been a LPG leak present. Which I agreed with.

Now my question(s) is(are) this(these)

Where in a system would LPG leak during normal operation if there is a
fault, if it was not apparent when not in use?

Can someone please layout the basics of a LPG system? I know Filler point to
tank with controller to ?

Is the filler point to the tank permanently pressurised? Like I think it is.
If the leak is in that area. Would the gas eventually leak out because of
the pressure it is under as I believe it would. I believe even a minor flaw
in that area would cause the system to empty fairly quickly and be very
noticable.

Any other ideas or tips about lpg installs would be gratefully accepted.

By the way when I handed the car back for its remedy work it was road
worthy. The dealer is now saying it is not road worthy.

Thanks in advance for your help

RichT


  #2 (permalink)  
Old July 4th 03, 09:06 AM posted to uk.rec.cars.fuel.lpg
Austin Shackles
external usenet poster
 
Posts: 533
Default LPG leak.

On or around Thu, 3 Jul 2003 20:34:57 +0100, "richt"
enlightened us thusly:

Can someone please layout the basics of a LPG system? I know Filler point to
tank with controller to ?

Is the filler point to the tank permanently pressurised? Like I think it is.
If the leak is in that area. Would the gas eventually leak out because of
the pressure it is under as I believe it would. I believe even a minor flaw
in that area would cause the system to empty fairly quickly and be very
noticable.


roughly speaking:

Most of the fillers, I think, have a valve in the fitting on the body. The
pipe to the tank does, generally, have pressure in it. There's a valve in
the tank which cuts off the inlet at 80% full (or should be) but this
doesn't seal the tank, I don't think for the most part that the filler pipe
is isolated.

the liquid gas in the tank goes via a solenoid valve to the engine bay, in a
small-bore copper pipe, to the vapouriser - all this is at tank pressure
(approx 100 psi or 7 bar) and when the system is live all the valves (tank,
line and vapouriser) are open. When the system is not live (i.e. ignition
off) the outlet pipe from the tank is still under pressure, but if it leaks,
only the gas in the pipe should escape, as the tank valve should be shut.

after the vapouriser, the gas is in vapour state and is at low pressure.

A common place for gas leaks is the connection from the filler to the pipe
which leads to the tank - the filler is almost never completely rigid, and
will move slightly when you attach the nozzle from the pump - if the
connection to the back of the filler is by a rigid pipe (e.g. copper) this
slight movement can cause the joint to become loose, but it should be a
simple job to tighten it. At most, the pipe and olive might need replacing.
I've had a small leak which produced a slight smell of gas on still days -
eventually traced it to this joint, and tightened it.

Flexible pipes are more reliable in this application, as the joint doesn't
get flexed, so it's less likely to loosen. Mind you, some of the flexible
pipes leave a bit to be desired in the matter of corrosion protection on the
fittings at the ends...


--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".
  #3 (permalink)  
Old July 4th 03, 07:17 PM posted to uk.rec.cars.fuel.lpg
richt
external usenet poster
 
Posts: 4
Default LPG leak.


"Austin Shackles" wrote in message
...
On or around Thu, 3 Jul 2003 20:34:57 +0100, "richt"
enlightened us thusly:

Can someone please layout the basics of a LPG system? I know Filler point

to
tank with controller to ?

Is the filler point to the tank permanently pressurised? Like I think it

is.
If the leak is in that area. Would the gas eventually leak out because of
the pressure it is under as I believe it would. I believe even a minor

flaw
in that area would cause the system to empty fairly quickly and be very
noticable.


roughly speaking:

Most of the fillers, I think, have a valve in the fitting on the body.

The
pipe to the tank does, generally, have pressure in it. There's a valve in
the tank which cuts off the inlet at 80% full (or should be) but this
doesn't seal the tank, I don't think for the most part that the filler

pipe
is isolated.

the liquid gas in the tank goes via a solenoid valve to the engine bay, in

a
small-bore copper pipe, to the vapouriser - all this is at tank pressure
(approx 100 psi or 7 bar) and when the system is live all the valves

(tank,
line and vapouriser) are open. When the system is not live (i.e. ignition
off) the outlet pipe from the tank is still under pressure, but if it

leaks,
only the gas in the pipe should escape, as the tank valve should be shut.

after the vapouriser, the gas is in vapour state and is at low pressure.

A common place for gas leaks is the connection from the filler to the pipe
which leads to the tank - the filler is almost never completely rigid, and
will move slightly when you attach the nozzle from the pump - if the
connection to the back of the filler is by a rigid pipe (e.g. copper) this
slight movement can cause the joint to become loose, but it should be a
simple job to tighten it. At most, the pipe and olive might need

replacing.
I've had a small leak which produced a slight smell of gas on still days -
eventually traced it to this joint, and tightened it.

Flexible pipes are more reliable in this application, as the joint doesn't
get flexed, so it's less likely to loosen. Mind you, some of the flexible
pipes leave a bit to be desired in the matter of corrosion protection on

the
fittings at the ends...


--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".


Thanks for the info.


  #4 (permalink)  
Old July 4th 03, 10:49 PM posted to uk.rec.cars.fuel.lpg
Terry Lyne
external usenet poster
 
Posts: 8
Default LPG leak.

Austin Shackles wrote in
:


Most of the fillers, I think, have a valve in the fitting on the body.
The pipe to the tank does, generally, have pressure in it. There's a
valve in the tank which cuts off the inlet at 80% full (or should be)
but this doesn't seal the tank, I don't think for the most part that
the filler pipe is isolated.


COP11 says that the fill valve on the tank should have a double check valve
to prevent reverse flow (plus an 80% shut off).
Under normal condidtions the filler pipe would therefore remain
pressurised. If the filer pipe leaked, then only the gas in the pipe should
escape.
Terry
  #5 (permalink)  
Old July 5th 03, 08:25 AM posted to uk.rec.cars.fuel.lpg
Austin Shackles
external usenet poster
 
Posts: 533
Default LPG leak.

On or around Fri, 4 Jul 2003 22:49:23 +0000 (UTC), Terry Lyne
enlightened us thusly:

Austin Shackles wrote in
:


Most of the fillers, I think, have a valve in the fitting on the body.
The pipe to the tank does, generally, have pressure in it. There's a
valve in the tank which cuts off the inlet at 80% full (or should be)
but this doesn't seal the tank, I don't think for the most part that
the filler pipe is isolated.


COP11 says that the fill valve on the tank should have a double check valve
to prevent reverse flow (plus an 80% shut off).
Under normal condidtions the filler pipe would therefore remain
pressurised. If the filer pipe leaked, then only the gas in the pipe should
escape.
Terry


fair enough. so the tank shouldn't be able to empty through the filler.
However, it'll still be a gas leak from the pipe.
--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Brevis esse laboro, Obscurus fio" (it is when I struggle to be
brief that I become obscure) Horace (65 - 8 BC) Ars Poetica, 25
  #6 (permalink)  
Old July 5th 03, 11:42 AM posted to uk.rec.cars.fuel.lpg
richt
external usenet poster
 
Posts: 4
Default LPG leak.


"Austin Shackles" wrote in message
...
On or around Fri, 4 Jul 2003 22:49:23 +0000 (UTC), Terry Lyne
enlightened us thusly:

Austin Shackles wrote in


Most of the fillers, I think, have a valve in the fitting on the body.
The pipe to the tank does, generally, have pressure in it. There's a
valve in the tank which cuts off the inlet at 80% full (or should be)
but this doesn't seal the tank, I don't think for the most part that
the filler pipe is isolated.


COP11 says that the fill valve on the tank should have a double check

valve
to prevent reverse flow (plus an 80% shut off).
Under normal condidtions the filler pipe would therefore remain
pressurised. If the filer pipe leaked, then only the gas in the pipe

should
escape.
Terry


fair enough. so the tank shouldn't be able to empty through the filler.
However, it'll still be a gas leak from the pipe.
--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that


Thanks for the info. I now have more info myself.

I have seen the vehicle today.

There is no lpg smell being generated inside the vehicle or around any parts
near the filler.

However allegedly there is a smell of lpg coming in through the air vents on
the dash. I was not allowed to drive it to test this. So where is it
possible for lpg to leak in the engine bay. The vent system is fed via
ducting in the engine bay from the bonnet.

Regs
RichT


  #7 (permalink)  
Old July 5th 03, 01:38 PM posted to uk.rec.cars.fuel.lpg
Austin Shackles
external usenet poster
 
Posts: 533
Default LPG leak.

On or around Sat, 5 Jul 2003 12:42:55 +0100, "richt"
enlightened us thusly:


Thanks for the info. I now have more info myself.

I have seen the vehicle today.

There is no lpg smell being generated inside the vehicle or around any parts
near the filler.

However allegedly there is a smell of lpg coming in through the air vents on
the dash. I was not allowed to drive it to test this. So where is it
possible for lpg to leak in the engine bay. The vent system is fed via
ducting in the engine bay from the bonnet.


it needs leak-testing under the bonnet. the smell in the gas is very
penetrating, as it needs to be. a small amount of gas makes a lot of smell.

You'll need some soapy stuff (gas fitters suppliers will have it in a bottle
for leak-testing, so will welders suppliers, and I think you can get aerosol
foam ones) and put it around any joints in the high-pressure side
(everything up to the vapouriser).

also visually inspect all pipework etc. on the "gas" side, i.e. outlet from
vapouriser and also the connections of ducting to inlet manifold etc.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Nessun maggior dolore che ricordarsi del tempo felice nella miseria"
- Dante Alighieri (1265 - 1321) from Divina Commedia 'Inferno'
  #8 (permalink)  
Old July 5th 03, 01:46 PM posted to uk.rec.cars.fuel.lpg
Dirty P Hucker
external usenet poster
 
Posts: 2
Default LPG leak.

On Sat, 5 Jul 2003 12:42:55 +0100, richt wrote:


"Austin Shackles" wrote in message
...
On or around Fri, 4 Jul 2003 22:49:23 +0000 (UTC), Terry Lyne
enlightened us thusly:

Austin Shackles wrote in


Most of the fillers, I think, have a valve in the fitting on the body.
The pipe to the tank does, generally, have pressure in it. There's a
valve in the tank which cuts off the inlet at 80% full (or should be)
but this doesn't seal the tank, I don't think for the most part that
the filler pipe is isolated.

COP11 says that the fill valve on the tank should have a double check

valve
to prevent reverse flow (plus an 80% shut off).
Under normal condidtions the filler pipe would therefore remain
pressurised. If the filer pipe leaked, then only the gas in the pipe

should
escape.
Terry


fair enough. so the tank shouldn't be able to empty through the filler.
However, it'll still be a gas leak from the pipe.
--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that


Thanks for the info. I now have more info myself.

I have seen the vehicle today.

There is no lpg smell being generated inside the vehicle or around any parts
near the filler.

However allegedly there is a smell of lpg coming in through the air vents on
the dash. I was not allowed to drive it to test this. So where is it
possible for lpg to leak in the engine bay. The vent system is fed via
ducting in the engine bay from the bonnet.


The garage is not allowing you to drive your own vehicle? Who are these clowns?



--
************************************************** ***************
1.5 GB of insane video clips! http://www.insanevideoclips.com
100s of photos of my parrots and 1000s of other photos from my digital camera
http://www.petersparrots.com

If only women came with pull-down menus and on-line help.
  #9 (permalink)  
Old July 5th 03, 02:00 PM posted to uk.rec.cars.fuel.lpg
Stewart Hargrave
external usenet poster
 
Posts: 185
Default LPG leak.

From a point at sea, to the circles of your mind, this is Austin
Shackles:


You'll need some soapy stuff (gas fitters suppliers will have it in a bottle
for leak-testing, so will welders suppliers, and I think you can get aerosol
foam ones) and put it around any joints in the high-pressure side
(everything up to the vapouriser).


Water and washing-up liquid in a spray bottle.

I know that some people will throw their hands up in horror at this
(LPGA and Corgi members, mostly) because of the corrosion issue, but
the received wisdom of uk.d-i-y is that this only applies to
washing-up liquid that has salt in it (eg, Fairy bad; Ecover good).

If you rinse it off afterwards I can't see that it is a real issue
anyway. I think it's just another way of trade associations marking
out a spuriously exclusive territory.


--

Stewart Hargrave

Faster than public transport


For email, replace 'SpamOnlyToHere' with my name
  #10 (permalink)  
Old July 5th 03, 07:13 PM posted to uk.rec.cars.fuel.lpg
Dirty P Hucker
external usenet poster
 
Posts: 2
Default LPG leak.

On Sat, 05 Jul 2003 15:10:30 +0100, Stewart wrote:

From a point at sea, to the circles of your mind, this is Dirty P
Hucker:


The garage is not allowing you to drive your own vehicle? Who are these clowns?


I bet it's insurance driven. I expect there could be a lovely (if
you're a lawyer) issue of liability here. If a garage suspected your
car of being dangerous, but still allowed you to drive it off their
forecourt and onto the public highway, imagine the insurance claims
that could be made against them in the event of an accident.

I agree, in every practical sense this should be absurd, but reality
these days includes the possibility of the greater absurdity of
enthusiastic litigation.


Can't they just pirnt off something saying they had warned the owner of the hazard, and any
problems due to this are at their own risk?

I wonder what would happen if you turned up with a spare set of keys
and stole your own car?


Hehehehe!

--
************************************************** ***************
1.5 GB of insane video clips! http://www.insanevideoclips.com
100s of photos of my parrots and 1000s of other photos from my digital camera
http://www.petersparrots.com

McMurphy fell 12 stories, hitting the pavement like a paper bag filled with vegetable soup.
 



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