mikey;1727 Wrote:Hey streaker. I was talking to a friend of mine who works as an HVAC guy and he told me that a 20# bottle would not work on a generator, because it would freeze up the regulator from the large volume of fuel that flows. He said I would need a 100# bottle to make it work. Have you used a 20# bottle for a long time period? I would not want to find out in an emergency that the 20's would not work.
That doesn't make sense to me. The volume of fuel is determined by the appetite of the engine, what difference does it make if it's being fed by a 20#, 30#, 100#, or 5# supply tank?
The pressure in any size tank at 70°F is about 127 P.S.I. and at 105°F it's about 210 P.S.I. so pressure variation between small and large tanks isn't an issue. The temperature of the liquid gas is about -44°F but that temp isn't realized until the gas expands.
That's all in the properties of the propane , not the size of the bottle it's in.
Source of info:
Is there a property changing dynamic involved?
Someone told me that he worled at a propand distributor and knew of someone who had a tank that was painted black, filled it to 20# and had it in the sun. He used it for a few hours and because of the heat it weighed slightly over 20#.
That statement shot the hell out of his credibility.
That just can't be. It would have had more internal pressure due to the heat but the volume and mass of the liquid wouldn't increase therefore the physical weight couldn't increase. That's like saying hot water weighs more than cold water. If in a pressure tight vessel, it won't happen, if the volume is decreased by usage it's an even more preposterous notion.
It's weight per unit of volumetric measure may change if not at maximum pressure to start with but a set amount captive vessel will weigh the same because it's occupying the same volume regardless of temperature.
I shouldn't have even typed this because someone will misunderstand and give me a ration of shit about it because they would have worded it differently, but a pound of feathers weighs the same as a pound of steel. It's the same principal, a pound is a pound and changing the temperature of it won't increase or decrease the total weight. Removing some of the volume will reduce the weight and that can't be compensated for by changing the temperature.
The volume of fuel being consumed is determined by the consumption of the engine, not the size of the supply tank. Higher volume of flow will cause a greater cooling effect but that flow is a function of the consumption of the engine, not the size of the supply.
ETA: The purity of the propane in regard to moisture content is a factor, higher moisture content will make a batch of propane more prone to freezing a regulator than pure (anhydrous) propane. Is there something about the dynamics of a smaller tank that affects the rate of the moisture separating from the gas?