Generator Propane Line Freezing

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RC2469

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Generac requires a 500 gallon minimum LP tank for an air cooled generator and 1000 gallon minimum for a liquid cooled on new generator installations. A 500 holds 400 gallons of LP and a 1000 holds 800.

We tell every customer about the 30/30 rule before installing their generator. You will get line freezing due to inadequate pressure/condensation formation when the tank is below 30% liquid volume and the temperature is at or below 30 degrees f. In cold weather, you are basically limited to 280 gallons of useful fule in a 500 gallon tank and 560 in a 1000. This is why you often see the old timers warming their LP tank with weed burners are burn barrels. I don't have the balls to do that myself.

Get as much volume as you can (i.e. twin 1000's), or look into LP tank heat blankets.
 

cowadle

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Generac requires a 500 gallon minimum LP tank for an air cooled generator and 1000 gallon minimum for a liquid cooled on new generator installations. A 500 holds 400 gallons of LP and a 1000 holds 800.

We tell every customer about the 30/30 rule before installing their generator. You will get line freezing due to inadequate pressure/condensation formation when the tank is below 30% liquid volume and the temperature is at or below 30 degrees f. In cold weather, you are basically limited to 280 gallons of useful fule in a 500 gallon tank and 560 in a 1000. This is why you often see the old timers warming their LP tank with weed burners are burn barrels. I don't have the balls to do that myself.

Get as much volume as you can (i.e. twin 1000's), or look into LP tank heat blankets.
would a heat exchanger on the fuel supply like we used to use on the old carburetor conversions work? i can see the liquid cooled engines with a heat exchanger but i guess for the air cooled maybe a duct from the engine cooling air could be used???
 

Firpo

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This is why you often see the old timers warming their LP tank with weed burners are burn barrels.
Grampa used to check for gas leaks with a match and a wet rag. Didn’t know about needing a larger tank but not much I can do about it now short of buying another, larger tank. Mine is only 250 gallons and no one said anything when I had both installed three years ago. I never let it get much below 40%. Been thinking about putting that insulating foam around all the exposed copper lines like is used on Air Conditioning lines. Don’t know if it would gain me anything.
 

Firemedic712

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I work on a refining unit that uses propane In unbelievable quantities in lines ranging from 3/4" to 26". Propane lines freeze when the propane is wet. They need to put some methanol in their system to raise the freezing point of the water. Or they need a low leg blow down to remove moisture from the system.
 

ConstitutionCowboy

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Those who have their propane lines freezing up likely have moisture in those lines.

At 100 below 0° F, propane vapor pressure is around 3 psi. Most home propane systems operate at 11 inches of water, or about .1 PSI. Unless there is moisture present, the line won't freeze.

Woody
 

Parks 788

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I was thinking a lack of scheduled servicing could be the issue with them burning up, that and possibly the air vents becoming clogged with debris. Who in their right mind would spend $10K+ on a backup system and not service the darn thing? I know people are bad about servicing their equipment but it’s beyond me why. I had to call Generac when my oil change came due and had a question of what oil to use because I hadn’t reached the hours to switch to synthetic….not even close. He told me the break-in oil is simply standard, non-synthetic oil and let me tell ya that stuff isn’t easy to find. Just about everything out there now is at least a synthetic blend.
As to the freezing that makes perfect sense that’s it’s contaminants in the propane and not the propane itself.

All great info!! 😁
I got my 24Kw installed last Fall. Only been doing the weekly automatic test every Monday afternoon. Ours is connected to Generac with a service that gives them real time updates and diagnostics of the generator. Super happy with our setup but it cost a lot more than $10K installed.
 

TerryMiller

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Generac requires a 500 gallon minimum LP tank for an air cooled generator and 1000 gallon minimum for a liquid cooled on new generator installations. A 500 holds 400 gallons of LP and a 1000 holds 800.

We tell every customer about the 30/30 rule before installing their generator. You will get line freezing due to inadequate pressure/condensation formation when the tank is below 30% liquid volume and the temperature is at or below 30 degrees f. In cold weather, you are basically limited to 280 gallons of useful fule in a 500 gallon tank and 560 in a 1000. This is why you often see the old timers warming their LP tank with weed burners are burn barrels. I don't have the balls to do that myself.

Get as much volume as you can (i.e. twin 1000's), or look into LP tank heat blankets.

I used to be in the business of delivering LPG to customers, both for home use and for irrigation engines, and I've NEVER heard of people warming their tanks with a weed burner. As for capacity, one can fill a tank to a higher level, but 85% is the recommended level, which would be 425 gallons in a 500 gallon tank and 850 in a 1000 gallon tank.

While home use doesn't use that much for "drawing down a tank," the irrigation engines definitely use a lot more than home use.
 

C_Hallbert

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Generac requires a 500 gallon minimum LP tank for an air cooled generator and 1000 gallon minimum for a liquid cooled on new generator installations. A 500 holds 400 gallons of LP and a 1000 holds 800.

We tell every customer about the 30/30 rule before installing their generator. You will get line freezing due to inadequate pressure/condensation formation when the tank is below 30% liquid volume and the temperature is at or below 30 degrees f. In cold weather, you are basically limited to 280 gallons of useful fule in a 500 gallon tank and 560 in a 1000. This is why you often see the old timers warming their LP tank with weed burners are burn barrels. I don't have the balls to do that myself.

Get as much volume as you can (i.e. twin 1000's), or look into LP tank heat blankets.
The fFeezing Point of liquid propane is -306.4°F. It must get pretty cold down there in Texas.
 

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