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Filling Pump Technical Question

Posted: Tue Oct 16, 2012 12:44 pm
by gerlewis
When Im filling up at Countrywide Stores, how do I know when to stop? I am worried im building dangerously high pressure into my tank! Unlike a conventional petrol station it doesnt click to a stop, rather the rate at which it fills becomes increasingly slower.

Am I building a massive PSI, Should I stop when it gets to a certain rate, or am I worrying about nothing?

Also is this typical of all LPF Filling Stations? or are others more 'Conventional'?



Thanks
Geraint

Re: Filling Pump Technical Question

Posted: Tue Oct 16, 2012 1:04 pm
by john_d
gerlewis wrote: Also is this typical of all LPF Filling Stations? or are others more 'Conventional'?

Thanks
Geraint

they usually just stop, just keep filling, ive never heard of a tank exploding due to excess pressure.

Re: Filling Pump Technical Question

Posted: Tue Oct 16, 2012 1:22 pm
by sijones
but let us know if it does :P

Re: Filling Pump Technical Question

Posted: Tue Oct 16, 2012 2:22 pm
by zipdip
yes keep filling it and let us know what happens :D I can see why you are worried but the gas tank is tested to far higher pressure than you will get from the lpg pump so it will stop,to be fair that is what you want to happen as you need that to collect data on what your lpg system milage is,it is one of the problems with lpg there is no standards unlike petrol where weights and measures can come along and measure a litre and make sure you get what you pay for,this is not the case with lpg,I think everyone who has lpg and fills up at different garages will have a story to tell,I had a car which would do 268miles to a tank and I would put in 44liters at a M4 garage I stopped at 47 litres,I suspect there must be somebody on here who is filling up from there own LPG home heating tank with a fridge pump and nozzle how do they get on with filling up. :roll:

Re: Filling Pump Technical Question

Posted: Tue Oct 16, 2012 2:35 pm
by sijones
The lpg pumps are calibrated, a litre of lpg is a liquid litre, just because you fill up at different places gives you different amounts of fill does not mean you are paying for 50 litres but actually only got 45 litres!

Re: Filling Pump Technical Question

Posted: Thu Oct 18, 2012 11:56 am
by gerlewis
So when u guys fill up, how do you know wheb to stop?

Re: Filling Pump Technical Question

Posted: Thu Oct 18, 2012 12:06 pm
by john_d
gerlewis wrote:So when u guys fill up, how do you know wheb to stop?
because the pump stops.

Re: Filling Pump Technical Question

Posted: Thu Oct 18, 2012 4:59 pm
by Gilbertd
There's a float inside your tank that operates a fill stop valve when the tank is 80% full. The pressure sensor in the pump detects that it can't put any more in so goes clunk and switches off. That's how you know the tank is full, no more will go in. Just occasionally you'll find a pump that doesn't go clunk and switch off, but just slows right down.

Re: Filling Pump Technical Question

Posted: Thu Oct 18, 2012 6:55 pm
by gerlewis
Thanks Gilbert,

the ones that slow right down and dont go clunk, would that cause a 'dangerous' buildup of pressure?
Apparently Countrywide stores dont have a shut off capability in their pumps.

Thanks,
Geraint

Re: Filling Pump Technical Question

Posted: Thu Oct 18, 2012 7:13 pm
by Gilbertd
Not to a dangerous level unless you stood there all day squeezing a bit more in. Even then, it would only get dangerous if you had an old, well corroded, weakened tank. There's a safety pressure relief valve in the tank too, that would allow excess pressure out rather than allowing anything to go bang. As soon as the pump slows, just release the button and don't try to squeeze another few millilitres in.

Re: Filling Pump Technical Question

Posted: Thu Oct 18, 2012 7:53 pm
by gerlewis
Thanks, yeah I will take your advice.