The little catch on petrol pump dispensers that won't work!
Chris Longhurst
>Does anyone know why the little catch on the handle of the majority of
>self service petrol pumps has been disabled. The catch itself is
>usually there but the little pin on which it should locate has usually
>been removed.
>
>There is a serious side to this question. It has been authoritatively
>reported that the benzene fumes given off by unleaded petrol are
>carcinogenic. It therefore makes sense to be able to stand back from
>the car when it is being filled.
This is why there have been developments in America (where those catches do
work) for a sort of external sleeve over the nozzle itself. It's a sort of
conertina-affair that makes a relatively good seal against the filler opening
and is slightly vacuum'd so that the fumes are all drawn off safely. I thought
I saw something on the BBC about it about a year ago, about them coming into
use over here, but nothing since then.
>At the moment I have to jam my petrol
>tank cap under the trigger of the pump handle in order to keep it
>depressed in order to do this..Since modern pumps
>have automatic cut off devices this shouldn't be an issue.
This is extremely dangerous, and possibly prosecutable. AFAIK those little
catches are highly sensitive so that the jolt of the pump cutting off kicks the
latch out and disengages the handle. In this way, if the nozzle drops out of
the car, the jolt of it "disengaging" with your car, and most certainly the
jolt when it hits the ground, would cut off the fuel flow. With your method, it
could fall out and spew petrol everywhere.
>Presumably it's not illegal since my local petrol station, which
>happens to be attended, has the pin and catch in working order. I
>presume this is so that the attendant can fill up more than one car at
>a time, which he does frequently.
I think the basis behind this is that "they are supposed to know what they're
doing - they're trained" They couldn't leave a benefit like that to us useless
car drivers could they :-)
>Would anyone care to join me in lobbying the major oil companies to
>have these catches fixed.
Yup. I would. Have you thought of another side-effect? Have you ever tanked-up
when it's cold? How long did it take for you to get any feeling back into that
hand? Now imagine trying to sign your name immediately afterwards as you pay
for the petrol with switch/visa/access etc. Most amusing. I carry a glove
around wedged in my front door pocket for when it's too cold to hold the pump
handle.
--
*** Pass or Pull Over! ***
Chris Longhurst
3D graphics engineer, graphic artist, car driver and non-caravanner.
email: chr...@division.co.uk or longh...@division.com
http://www.division.co.uk/~chrisl/
--------------------------------..oooOOOooo..--------------------------------
Standard disclaimer: The views expressed in this item are entirely my own.
--------------------------------..oooOOOooo..--------------------------------
David Shepherd
: Have you ever thought what would happen if you had the catch engaged,
: then walked away to do something else, the petrol filler nozzle falls
: out, the petrol spews all over the floor, someone lights a cigarette,
Probably the reason for all those "no smoking signs" you see around
petrol station forecourts :-)
--
--------------------------------------------------------------------------
david shepherd
SGS-THOMSON Microelectronics Ltd, 1000 aztec west, bristol bs12 4sq, u.k.
tel/fax: +44 1454 611638/617910 email: d...@bristol.st.com
www: http://www.inmos.co.uk/~des/welcome.html
"whatever you don't want, you don't want negative advertising"
huge
>I *believe* (someone correct me if I'm wrong) that this is the reason
>why petrol fillers have the clp removed, but in *some* cases they may
>be left in for diesel fillers since this does not have the same flash
>point as petrol
OK, you're wrong. The pump handle 'trips' as soon as there is any back
pressure and unclips the clip, stopping the flow, exactly as for the
'normal' handle.
This irritates me, since I was a petrol pump attendant in 1971, and
it was dead hady being able to do 2 or 3 cars at the same time.
--
Regards,
Huge.
-------------------------------------------------------------
Hugh J.E. Davies, Bedfordshire, England.
"The road to Paradise is through Intercourse."
Daniel Bird
>>Does anyone know why the little catch on the handle of the majority of
>>self service petrol pumps has been disabled. The catch itself is
>>usually there but the little pin on which it should locate has usually
>>been removed.
>>
>>There is a serious side to this question. It has been authoritatively
>>reported that the benzene fumes given off by unleaded petrol are
>>carcinogenic. It therefore makes sense to be able to stand back from
>>the car when it is being filled.
>This is why there have been developments in America (where those catches do
>work) for a sort of external sleeve over the nozzle itself. It's a sort of
>conertina-affair that makes a relatively good seal against the filler opening
>and is slightly vacuum'd so that the fumes are all drawn off safely. I thought
>I saw something on the BBC about it about a year ago, about them coming into
>use over here, but nothing since then.
>>At the moment I have to jam my petrol
>>tank cap under the trigger of the pump handle in order to keep it
>>depressed in order to do this..Since modern pumps
>>have automatic cut off devices this shouldn't be an issue.
[snip]
Some general comments:
1. Petroleum spirit is a highly flammable substance and its
distribution is therefore strictly controlled by legislation.
DERV is not subject to such control.
2. Petrol stations all have to be licenced and it is usually a
condition of the licence on self-service sites that any device
allowing the nozzle to be locked on must be removed. The reason for
this is twofold: first, the automatic shut-off device in the nozzle is
primarily there for the convenience of customers and is not classified
as a safety device - it only works if the nozzle is at a certain
angle; second, in the event of the nozzle falling out (as previously
described) the catch is _not_ guaranteed to release - they are usually
quite sensitive, but this is again for convenience rather than safety.
In both these cases the potential hazard is of a large quantity of
petrol spilling all over the forecourt (with attendant fire/explosion
risk) or over any person standing nearby (much higher health risk from
physical contact with petrol than from fumes). At attended service
sites the catches are allowed because, in theory, the attendant will
have been trained and will be alert to the dangers.
3. There _are_ already some sites in operation in the UK with Vapour
Recovery (the technique you describe) but as yet it is optional and
the high cost involved means it is not widely used at individual pump
level. However, it is becoming quite common on the main vents
(whenever a tanker refills a garages underground tanks the whole of
the vapour within the tank is usually discharged into the atmosphere.
Vapour recovery prevents this), and this probably has a more
significant effect on reducing the overall level of pollutants in the
air.
4. It does _not_ 'make sense to stand back from the car when being
filled'. Dispensing petrol is a dangerous business and you should be
paying attention to what you are doing. Accidents are few but this is
only because the rules are so strict - too many people become blase
about the risks. Remember, a pint of petrol is sufficient to propel a
ton block of metal about four miles.
5. Finally, putting the risks into perspective, even if benzene is a
carcinogen you are still 1000's of times more likely to die in a motor
accident driving your car than you are from breathing a few fumes.
++Daniel Bird+++++++++...@globalnet.co.uk++
++Nottingham, England++++...@compuserve.com++
++++ Disclaimer: I don't believe in disclaimers +++++
Chris Longhurst
>Some general comments:
>
<all valid comments snipped>
Those were all good, valid points, but why then do the Americans allow this
catch to be left on, even in self-serve stations? You don't hear of many (if
any) pump-related accidents over there. Is it a different system of something?
Or do they just trust their drivers more?
Rajesh Varia
jo...@yrsk.demon.co.uk "John Laird" writes:
>
> I would not be surprised if today's cars are more difficult to fill, what
> with changes in fuel tank and filler design and location. Certainly, my
> Peugeot 309 could be enticed to blow back very easily. This would suggest
> that cut-outs are probably best avoided. Frankly, if you don't know to
> within a gallon or so, how much extra the tank will hold, and slow up a bit
> as you near that point, you shouldn't be driving in the first place.
> --
> ----
> John Laird, Yezerski Roper ( jo...@yrsk.demon.co.uk ) "Sigs? Gave them up"
>
Having worked part-time for a year at a petrol station recently, I have
noticed that Metros are definitly the worst for blow-back and spilling
petrol all over the nice and clean forecourt. These cars are usually
driven by women who seemed to be more concerned by the damage to their
dresses rather than the danger of fire.
--
Rajesh Varia r...@c4rv.demon.co.uk
Stephen Wilcox
John Laird <jo...@yrsk.demon.co.uk> wrote:
>As many have pointed out, it's considered safer for just one or two idiots
>to be able to spill petrol all over the place, rather than every idiot who
>droves in. So, self-service pumps have the cutout mechanism disabled.
And it's far easier to sack an idiot who works for you for creating a
fire risk by spilling petrol on the forecourt than it is to sack an
idiot who doesn't work for you.
--
Stephen Wilcox ** Since singing is so good a thing,
wil...@maths.ox.ac.uk ** I wish all men would learne to sing.
Karl Meyer
>Karl Meyer wrote:
>> You don't actually use high-grade formula-one petrol in your car
>> Sorry Chris but for a few years they have been using Pump petrol. Hence
>I thought that was fuel supplied by the petrol companies which was a higher grade
>than standard stuff? If it's not then how come the teams always moan about how much
>it costs. If it was 57p/litre for them, they shouldn't have any problems, not with
>tyres costing 200 quid a piece!
Nope standard premium unleaded (engine management rather than
environmental reasons). The high octane throat burning stuff was outlawed
a while back as Ferrari were in danger of poisoning the whole pit lane
with their home brew - I don't think people complained because it was
dangerous but because it made their cars go faster!
OTOH its probably filtered and otherwise cleaned to improve burning but
no extra additives of any kind.
Indy cars however use methanol which is very very flamable (and burns
almost invisibly) Having seen (or not) a lab fire from this stuff I
prefer petrol any day.
Chris Longhurst
>
> Chris Longhurst <chr...@division.co.uk> wrote:
>
> >FYI: petrol on a hot exhaust doesn't light. It just fizzes a bit.
>
> Try telling that to Eddie Irvine and whoever-it-was that Bennetton tried
> barbecuing last year at Hockenheim (any clues anybody?)
Jos Verstappen. You don't actually use high-grade formula-one petrol in your car
do you? It's more volatile than your joe-average high-street petrol.
Karl Meyer
>Philippa Hogben wrote:
>>
>> Chris Longhurst <chr...@division.co.uk> wrote:
>>
>> >FYI: petrol on a hot exhaust doesn't light. It just fizzes a bit.
You don't actually use high-grade formula-one petrol in your car
>do you? It's more volatile than your joe-average high-street petrol.
Sorry Chris but for a few years they have been using Pump petrol. Hence
the little problem Benetton and Williams had with Elf petrol at the
beginneing of the year (the batches of pump fuel were different)
Chris Longhurst
> The clip is left on diesel pumps 'cos if it was removed your truck driver
> would start complaining of fatigue while pumping 200 litres into his
> v. large tanks.
I get bored filling my tank - it's 70 litres. Most large family cars have large
tanks now so quite why the petrol companies still won't put the catch back on is a
mystery. Especially in the winter - fuel nozzles get cold enough in the middle of
summer when they're pumping - in the winter it's unbearable. It takes me twice as
long coz I have to keep changing hands and warming the other one back up. And then
trying to sign for the petrol at the kiosk with cold hands?.......
Simon Hobson
Chris Longhurst <chr...@division.co.uk> wrote:
> >At the moment I have to jam my petrol
> >tank cap under the trigger of the pump handle in order to keep it
> >depressed in order to do this..Since modern pumps
> >have automatic cut off devices this shouldn't be an issue.
>
> This is extremely dangerous, and possibly prosecutable. AFAIK those little
> catches are highly sensitive so that the jolt of the pump cutting off kicks the
> latch out and disengages the handle. In this way, if the nozzle drops out of
> the car, the jolt of it "disengaging" with your car, and most certainly the
> jolt when it hits the ground, would cut off the fuel flow. With your method, it
> could fall out and spew petrol everywhere.
Sorry, but if you look at the actual relase action you will see that it
makes no difference. When the mechanism detects the end of the nozzle is
submerged (which is done with vacuum, not back pressure) it triggers a
'trip free' system which releases the mechanism from the operating handle.
It is done so that the fuel will stop whether the handle is held by a hand
or the little catch.
If you think about it, if they just tripped the catch on the handle, most
drivers would get covered with petrol at regular intervals because holding
the handle up would override the detector.
The actual detector mechanism works by forming a partial vacuum by venturi
action of the fuel through a restriction. This vacuum draws air up a small
tube inside the nozzle (you can see it if you look down the end) and
nothing happens until the end of the nozzle is submerged. When this
happens, fuel is drawn up the tube and since it doesn't flow through an
orifice as easily as air the vacuum level increases and is used to trip the
handle mechanism.
It is for this b*****y reason that diesel foams at forecourt pumps - the
filler mechanism actively adds air to the fuel stream in the nozzle ! Being
able to compare this with a filler without a trip mechanism (filling
tractors down on the farm) I can tell you that without this air addition,
filling is a lot easier !
TTFN, Simon