# new member with a generator question



## james24641 (Nov 4, 2017)

Hello,

I have a technical question about the duramax 4850EH propane/gas generator. I have two questions: the first question: I know the generator is designed to use tank pressure to its regulator with primer from 20lb barbecue tanks. I have installed a high pressure regulator (60psi) to deliver gas from a 100lb cylinder to the generator through a 15ft stainless high pressure hose connecting directly to the generators regulator. It seems to run fine. I know the 60 psi is not tank pressure which runs from 100psi up to 200psi in the hot summer, so will this pressure work under load and cold conditions usually around 20-30deg f occasionally zero f temps sometimes??? 

My second (2nd) question is about pressure in the lines. I noticed when I installed the high pressure regulator and hose. When I was done and the generator was off and I turned off the tank gas at the tank cutoff, the gauge on the tank regulator showed a slow drop in the system. The system being the tank high pressure regulator, stainless 15ft hose and the regulator on the generator. It drop from about 62 psi to around 55psi in 20-30 mins and then it was around 45 psi in 3 hours. I checked the entire regulator, all connections and everything with soapy water and no leaks show. Does the generators built in regulator slowly leak pressure from the system normally in the time span I gave with the engine not running??? I want to make sure everything is ok??? Thank you guys again.


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## aandpdan (Oct 8, 2012)

Hi,

The pressure in the 20lb and 100lb tanks is the same and varies.

Whether or not it runs in 20-30 degree weather, I'm guessing you mean fahrenheit, that depends. Propane is stored as a liquid and "boils off" to produce the gas that your engine runs on. If you've ever seen a propane tank ice up on the outside the demand is too great and you could run out of gas even though there is plenty of propane in the tank. Once the tank warms up, it'll boil off more and you'll be able to run your generator again. Bigger tank, more vaporization, longer run when cold.

No regulator should be designed to leak.


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## james24641 (Nov 4, 2017)

thank you for replying. What I wonder is that pressure testing on some sites say that if the pressure in the lines stay good for 3-4 mins and no leaks all is good. they say no system is airtight for a long period. But, I noticed today there was still around 25 psi in the lines from overnight. if the pressure is not dropping that fast, what do you think it is? do you think it is safe to use? is the leak through the gen regulator? I cannot find any leaks on the connections points? what should I do? what would you do? thanks again. sorry for the many questions.


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## KRE (Nov 29, 2011)

james24641 said:


> What I wonder is that pressure testing on some sites say that if the pressure in the lines stay good for 3-4 mins and no leaks all is good. they say no system is airtight for a long period. But, I noticed today there was still around 25 psi in the lines from overnight. if the pressure is not dropping that fast, what do you think it is? do you think it is safe to use? is the leak through the gen regulator? I cannot find any leaks on the connections points? what should I do? what would you do? thanks again. sorry for the many questions.


Unless you have a vacuum lock off, or a voltage operated valve at the vaporizer it's most likely very slowly leaking into the engine. You can test that via removing the carb intake an bagging it air tight, an doing the same with the exhaust. If the bags inflate that's where it's going. You should never leak test any gas system with over 5-10psi max as many things influence pressure readings, but at low pressure you can get correct readings very quickly. Pressurize the system to 5 psi, shut the fuel valves, soap everything(including gauge/hose ect) an watch for pressure drop an bubbles. If the pressure stays the same for 10 minutes, your good, if not locate the leak. If you have lines underground you can have leaks in a solid line that will not smell above ground, so testing before an after is required, if no leaks there the line is the issue and you'll have to dig it up an replace it. (Some soil will eat at copper,(an black iron/galvanized pipe) the reason most copper/pipe now has a plastic yellow shield or 100% plastic) (I know you have no lines below grade but others that read here might)

Hope this helps,
Kenneth


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## james24641 (Nov 4, 2017)

thank you very much. I will definitely do more testing. thanks again. James.


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