Forum Discussion
blkfe
Sep 17, 2007Explorer
This Chart shows the max btu/hour that can be drawn from a 30 lb tank without freezing up.
+60F 32,000
+50F 28,300
+40F 24,700
+30F 21,000
+20F 17,300
+10F 13,700
0 10,000
-10F 6,400
-20F 2,700
This is a worse case scenario. For instance, when a 20# cylinder is full it can run a 16hp engine for quite some time in 40 degree weather before there will be any freezing problem. But if you wanted to use up all the gas in a cylinder, it would have to be sized according to the chart.
Here is why. Propane is stored as a liquid under pressure and boils to produce a vapor that is drawn off at the top for the engine to use as the fuel. Because propane boils at -44° (below zero), the gas will freeze if it can not absorb enough ambient heat to compensate for the boiling process. The bigger the cylinder is compared to the amount of load, the warmer it is outside, the warmer the cylinder is kept, all are a determining factor in the likelihood of a cylinder freezing up.
If a sweat or frost line forms around the cylinder at the level of the fuel, this is a telltale sign that the cylinder over worked and is in the process of freeze up. If the gas does freeze, it will stop producing vapor and the pressure inside the cylinder will drop to as low as zero psi which will cause the engine to stop running.
To compensate for an undersize cylinder, two cylinders can be tied together using a tee check and pigtails. Some customers set the cylinder near the exhaust of the engine to help keep the cylinder warm and have no problem using smaller tanks on bigger engines. This practice needs to be carefully monitored so that the cylinder does not overheat and cause the relief valve to check off.
This is not from my brain...it is from this website.
http://www.yamaha-propane-natural-gas-generators.com/fuel_consumption.htm
Hope it helps!
Brad
+60F 32,000
+50F 28,300
+40F 24,700
+30F 21,000
+20F 17,300
+10F 13,700
0 10,000
-10F 6,400
-20F 2,700
This is a worse case scenario. For instance, when a 20# cylinder is full it can run a 16hp engine for quite some time in 40 degree weather before there will be any freezing problem. But if you wanted to use up all the gas in a cylinder, it would have to be sized according to the chart.
Here is why. Propane is stored as a liquid under pressure and boils to produce a vapor that is drawn off at the top for the engine to use as the fuel. Because propane boils at -44° (below zero), the gas will freeze if it can not absorb enough ambient heat to compensate for the boiling process. The bigger the cylinder is compared to the amount of load, the warmer it is outside, the warmer the cylinder is kept, all are a determining factor in the likelihood of a cylinder freezing up.
If a sweat or frost line forms around the cylinder at the level of the fuel, this is a telltale sign that the cylinder over worked and is in the process of freeze up. If the gas does freeze, it will stop producing vapor and the pressure inside the cylinder will drop to as low as zero psi which will cause the engine to stop running.
To compensate for an undersize cylinder, two cylinders can be tied together using a tee check and pigtails. Some customers set the cylinder near the exhaust of the engine to help keep the cylinder warm and have no problem using smaller tanks on bigger engines. This practice needs to be carefully monitored so that the cylinder does not overheat and cause the relief valve to check off.
This is not from my brain...it is from this website.
http://www.yamaha-propane-natural-gas-generators.com/fuel_consumption.htm
Hope it helps!
Brad
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