andrew
What size black iron supply line should I use for a 60kw Generac, using LPV fuel, located ~45 feet (with five 90 degree bends) from 500gal fuel tank. Generator is a model QT06024KVSX and requires 327cu ft/hr at 100% rated load. I've calculated the line to be 1-1/4 inch. Is this too large of a line?
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Skip Douglas SkipD
You can use [URL="http://www.mygenerac.com/PublicPDFs/0172610SBY.pdf"][COLOR=Blue][U]this document by Generac[/U][/COLOR][/URL] along with the user's manual supplied with the generator to help you size the fuel system components.

Your pipe size is not quite adequate according to the chart on page 8.

You may find page 9 interesting regarding tank sizing. Consider the low temperature range for winter in your area, as you may want to up-size the tank for cold-weather performance.
Skip Douglas
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andrew
Chart on page 8 (fuel line size)

Okay, what am I missing. I've looked at the chart on page eight of the Generac manual, and I come up with 1-1/4" pipe. I located the 60kw in the left column and the 45 feet run distance in the table values. Following that column to the top of the table indicates a 1-1/4" pipe. What am I doing wrong? Thanks for the help.
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andrew
Fuel line size

What am I doing wrong? Using the chart for LPV on page eight I located the 60kw unit in the left column then found the run length (45') in the table values. I followed that to the top of the chart and it indicates a 1-1/4" pipe. What am I missing?

Thanks for the help.
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Skip Douglas SkipD
The five 90° bends are what would make me move up to the next pipe size (1-1/2") rather than use a pipe length that would be right at the limit for 1-1/4". It's always good to have just a little headroom in sizing things.

Regarding your choice of tank size:

What's the lowest winter temperature that you experience?

What's the BTU/hour fuel demand rating of the generator (from your user's manual)?
Skip Douglas
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andrew
Fuel line and tank size

S. Douglas,

It rarely gets into the 20's here. It is also doubtful that the generator will ever be required to run at 100% other than for load testing. At 100% the fuel consumption is rated at 9gal/hour or 836,600BTU/HR if my math is right. I will use the larger (1-1/2') line for the fuel supply, but the tank will be difficult to change. In your opinion will the 500 gal tank work if the generator is used at 75% capacity?

Thanks for the help.
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Skip Douglas SkipD
andrew;8637 wrote:
In your opinion will the 500 gal tank work if the generator is used at 75% capacity?
The key is how fast you're trying to convert liquid to gas at the ambient temperature in the tank. Surface area is one of the key factors in being able to convert from liquid to gas which is why the larger tanks can supply a larger load. All I know is what the chart shows, as I don't use propane and don't have experience with using it for a generator.
Skip Douglas
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ohmslaw
Andrew,
Is your tank above ground? Does it supply other appliances? I would make sure you keep it close to full when the weather turns cold.

I would also plumb this unit with a high pressure regulator at the tank and a low pressure one at the unit. This would allow a small diameter pipe at 10 psi and then drop to 14"WC at the generator.

Tim
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d11gnccer
andrew;8637 wrote:
It is also doubtful that the generator will ever be required to run at 100% other than for load testing.


Doesn't matter. Size it for full load so the customer gets what they pay for... unless you are the customer and in that case, do what you wish.
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rico567
I am currently attempting to determine if our gas system is sized correctly for a 10KW Generac system. We have a 1K gal bulk tank with a red high-pressure regulator on it, and a line (I'm guessing about 3/8") leading to the house, where there is a larger green regulator about 4-5" in diameter, labeled at 10 psi / 13" WC. The generator will be placed about 10 feet to one side of the regulator.
While our tank is large enough for this application (the generator and appliance (furnace, water heater, and cooktop) inputs are less than the tank's ability to supply vapor at 0°F, my question lies with the regulators and lines. I suppose our propane supplier, who will be doing the hookup anyhow, can determine this.
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Skip Douglas SkipD
rico567;9032 wrote:
I am currently attempting to determine if our gas system is sized correctly for a 10KW Generac system. We have a 1K gal bulk tank with a red high-pressure regulator on it, and a line (I'm guessing about 3/8") leading to the house, where there is a larger green regulator about 4-5" in diameter, labeled at 10 psi / 13" WC. The generator will be placed about 10 feet to one side of the regulator.
While our tank is large enough for this application (the generator and appliance (furnace, water heater, and cooktop) inputs are less than the tank's ability to supply vapor at 0°F, my question lies with the regulators and lines. I suppose our propane supplier, who will be doing the hookup anyhow, can determine this.
Go up to post #2 in this thread and click on the link to Generac's generator sizing document. There's some good information about propane system requirements in that document.
Skip Douglas
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ohmslaw
The green regulator will not have an issue with that load (500,000 BTUs?). You could add a regulator at the generator also. The 10 psi line will supply a lot of fuel.
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GeneWreck
I had a similar problem during the installation of my home unit. I spent some time on the phone with the installer, Mister Quik, and the manufacturer and we agreed that the line was too small. After we bumped up to 1 1/2, I had no further issues--it runs like a top.
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GeneWreck
I have an update. Our [url=http://www.mrquikhomeservices.com]heating[/url] unit is still doing really well. I talked to our Mister Quik installer again. He seems to think bumping up the unit is the best option for the trouble. A regulator works fine, but he really recommended the new unit.
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