Rick Davis wrote:
<snip>

Generally there is a float inside the tank that drives either a mechanical

> guage or a rheostat for an electric gauge much like the fuel gauge in a car.
>
> The problem with the new valves is they also have a float so the valve
> mounted gauges have to go, at least for the moment.
>
> when the tanks are easy to get at just pour a cup of hot water on the tank.
> the gas level is
>
> where the tank goes from hot to cold. Under the right weather conditions
> and gas flow rate a frost line will appear at the gas level
>
> >
> Rick Davis 1602
> 54 Safari
> 69 Ambassador
> 70 Globetrotter
> Amateur Radio K8DOC
> NSS 14876

We have discover lately that someone came up with an OPD valve that used a check
ball rather than a swing arm float. I suspect that will be the one used with
gauge tanks. The gauge tanks we have taken apart use a swing arm float. The
position information is typically transferred out of the tank by a magnetic
pickup. You know, one magnet is attracted to the opposite ends of another.

Charlie