Thread: short fueling?

do tank fuel level gauges need power to work?

Originally Posted by Pedro_The_Swift

do tank fuel level gauges need power to work?

Yes

As a matter of interest, the dispensing pump pressure is adequate to re-compress the gas vapour back into liquid form.
You will most probably experience slower fill rates when filling from an underground LPG tank than an above ground tank, more so in hotter weather conditions.
To the best of my knowledge most, if not all States & Territories have adopted the following Standard as regulation: AS/NZS 1425: LP Gas fuel systems for vehicle engines.

Originally Posted by Collins

As a matter of interest, the dispensing pump pressure is adequate to re-compress the gas vapour back into liquid form.

Not quite. There is a heat exchange process that takes place when liquefying LPG from vapour and it's not instantaneous. Put your hand on a recently filled tank and it will be quite warm to the touch from the rapidly compressed vapour. When the temperature drops the vapour returns to liquid. A tank rapidly filled from near empty to 90+% will have so much pressure in it that most filling pumps will slow right down and stop.

Originally Posted by Collins

To the best of my knowledge most, if not all States & Territories have adopted the following Standard as regulation: AS/NZS 1425: LP Gas fuel systems for vehicle engines.

This is the copyright protected standard that I mentioned earlier. It costs some $200 for a legit copy. All LPG fitters should have the latest copy (from 2013) available for reference.

Originally Posted by Collins

Yes

No. The tank level gauge (sender unit) shows the level by mechanical means and a simple magnetic coupling. The dash gauge needs power.

Please bear with me--

hmm, my thoughts--
The G84 tank reads full, but the LED gauge lights show only two green lights, so-
as far as i can tell the G84 tank is not being used,, or, the gauge that controls the swapover to ULP is connected to the second underlung tank. (which makes sense)
so with two(3?)hydostatic valves in play,, ( I'm assuming the valve just shuts down whichever tank is empty first??)
how does it pick which one to use first?
or more importantly,
use last.

Originally Posted by Pedro_The_Swift

Please bear with me--

hmm, my thoughts--
The G84 tank reads full, but the LED gauge lights show only two green lights, so-
as far as i can tell the G84 tank is not being used,, or, the gauge that controls the swapover to ULP is connected to the second underlung tank. (which makes sense)

The LPG gauge will be connected to whatever sender unit/s the LPG fitter connected it to. I suspect he just left it connected to the existing underslung tank/s.

Originally Posted by Pedro_The_Swift

so with two(3?)hydostatic valves in play,, ( I'm assuming the valve just shuts down whichever tank is empty first??)
how does it pick which one to use first?
or more importantly,
use last.

There could be a number of hydrostatic valves down there somewhere but the important bit is the non return valves of which there should be three, one for each tank upstream of the one required hydrostatic (line relief) valve. These non return valves aren't active elements, they are just dumb spring loaded one way valves. They can't "pick" anything. Typically, hydrostatic valves are made in one unit with two non return valves. Separate non return valves are available too.

So the tank/s that drain first will be the hottest, ie at the highest pressure. In summer this usually means the one nearest the exhaust, then the one on the other side, then lastly the one in the air conditioned cabin. In winter the one inside will usually drain first due to cabin heating. Obviously the drain rates will always depend on the temperature of the LPG in each tank at any given moment.

If you had a separate filler for the G84 tank you would legally be allowed to have a manual switch (connected before the electric solenoids) to drain it separately so you would know exactly where you were up to. This is my preferred way of dealing with multiple tanks. Either a "reserve" switch for a smaller auxiliary tank or a two way switch to choose between two tank sets.



http://www.amrgas.com/p_hydrostatic_tee_valves.html

Yep,, a manual switch is the only way to ensure the underslung tanks with the gauge drains last,,

and they have fitted a second filling point for the G84.

The BSL strikes again,,
Hardware update first-- A second intake was fitted for the new triple tank, it was attached to the Tow hitch frame and the filling seems to work much better
Now,,,,,,
After dumping the van at Genoa rest area we started off to Mallacoota,after ten minutes the car stalled around a bend,, fired up after a bit then stopped, Di said she could hear a funny noise and then said,--"Dumm De Dum Dum"-- I can smell gas!
Long story short it appears a high pressure line has broken. In Mallacoota. A long way from anywhere.
RACQ/V will tow everything to Bairnsdale,, apparently. Still dont know who the repairer is.
I wonder what a Colorado is worth?