Suspect I should know this, but it's bothering me and I don't seem to be able to do any proper work today until I find out "How does a petrol pump nozzle know when your tank is full and switch itself off?"
I have googled without result so over to the collective wisdom of a.f.l to put me out of my misery.
TIA
David
Near the tip of the nozzle is a small hole, and a small pipe leads back from the hole into the handle. Suction is applied to this pipe using a venturi. When the tank is not full, air is being drawn through the hole by the vacuum, and the air flows easily. When gasoline in the tank rises high enough to block the hole, a mechanical linkage in the handle senses the change in suction and flips the nozzle off. Here's a way to think about it -- you've got a small pipe with suction being applied at one end and air flowing through the pipe easily. If you stick the free end of the pipe in a glass of water, much more suction is needed, so a vacuum develops in the middle of the pipe. That vacuum can be used to flip a lever that cuts off the nozzle.
The next time you fill up your tank, look for this hole either on the inside or the outside of the tip.
from
And how do they know when it's pissing with rain, I'm in my shirt sleeves, dying for a pee and therefore they need to deliver about 1 litre per minute....
TonyB
An Esso garage near me had their iesel pump delivery rate way to low for a while. There have been times when two or three cars have filled with petrol and driven off before the 110's tank was full.
Indeed...... However, for those using diesel, always go the HGV pumps - much quicker, and a lot of the time no queue!
Richard
Yeah but they where probably only filling up with 25l each not 75...
As to using the HGV pumps good tip, they also have the locking pins in place don't they? So you don't have to stand there and hold the trigger. Trouble is I don't think Tesco have HGV pumps, that 5p/l off is worth having...
On or around Fri, 11 Feb 2005 08:59:09 +0000 (UTC), beamendsltd enlightened us thusly:
bigger nozzle, generally, make sure it'll fit your car, to avoid embarrassment.
and also, beware of truckers looming up and being (rightfully) pissed off that you're occupying the HGV pump, when they don't have the option of using the car pump.
If it's a quiet time of day, fair enough.
Sorry, but tough luck on em! First come, first served..... besides. the 110 and LDV are commercials. I'm affraid I don't have alot of time for truckers these days..... (note to self, stop now before starting a rant....)
Richard
Yes, but my 2.4 petrol will drive away much more slowly....
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