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with that said the high part of the flow needs to be at below 75% of the rated of the demand regulator...
Starting watts of this generator is 27kW watts.

LPG (Standard)
29.8 kW
LPG (High Flow)37.3 kW
.75 of 37.3kW is 29.975. Does that suggest to you, that I in fact need the high flow regulator?
 

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It is confusing that they say "with 1/2 inch outlet" because they don't list any such animal on their website. The model 039-31173-1 is their high flow regulator (with primer. remove -1 for unit w/o primer). You can compare the 039-31173-1 and the 039-122 and see that the big difference is the spring.
Do you need the primer or does the primer just make it easier to start? GARRETSON IMPCO KN LOW PRESSURE REGULATOR # 039-31173 (marussiat.top)
 

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That is one included with my kit.
Yes, that is the standard demand valve shipped with almost every conversion kit.

Do you need the primer or does the primer just make it easier to start?
The primer button makes purging a line of air easy, but you could also do that by just loosening a fitting. The button also helps when starting the gen much like a choke when using gasoline. However, the primer button is not always needed to start the engine. If my engine is not too cold, then I just give it 1/2 choke (which increases the vacuum) and it will start right up without using the primer button. Otherwise, I do use the primer (without choke) to increase fuel richness for starting. I know that many will say that you never use the choke for propane or NG. But I know what works with my genny and that may not work with someone else's setup. So, go with what works for you.


...why he scoffed at the idea of measuring regulator pressure. The first and second stage regulators are from reputable companies that he believes are almost certainly delivering the correct pressures.
You might be delivering the "correct" pressure at the source, but what is it at the gen after running through your lines. Without knowing the pressure you are dealing with at the genny when it is struggling under load, you are just guessing at the cause/solution. Like a good detective, you have to eliminate all possibilities one at a time to arrive at the correct solution.

As far as air in the tank(s), I have never experienced that with a tank that has been properly filled. Maybe a new tank might have some air in it after initial filling, but a refilled tank should not have any significant amount of air in it.
 

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As far as air in the tank(s), I have never experienced that with a tank that has been properly filled. Maybe a new tank might have some air in it after initial filling, but a refilled tank should not have any significant amount of air in it.
Tanks are new. They have never been refilled.
 

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Discussion Starter · #225 ·
My home is about 3500 sq feet with a lot of devices and appliances that are always on. The btu required at startup of my 2006 model 4 ton or 3.5 ton central air along with the other devices and appliances in my home has to be relatively high. I ran the generator for about an hour. Gentleman at propane shop ask me if the tank sweat at all. When I said yes, he replied that I for certain had a tank size issue. It is also partly why he scoffed at the idea of measuring regulator pressure. The first and second stage regulators are from reputable companies that he believes are almost certainly delivering the correct pressures. There he felt was not the place to start. Manifolding two tanks hasn't solved the issue.

Wouldn't just opening the bleeder screw on the almost full vertical propane tanks let the "air" out since it's likely sitting on top of the propane? If not, how do you fix an almost full propane tank that may have not been properly purged? Any ideas?
burn off all of the fuel, then vac the tank clean at -30 vac for a few hours.
then valve in the quality lp vapor.

hard to fix when it is a mix of gasses ..
at least to get it perfect..
 

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I’ve heard that a lot propane companies are mixing large amounts of butane into their fuel. It’s boiling point is much higher then propane which means worse cold weather performance Though their energy content is the same.
 

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[
As to the question of whether a soft-start is needed or not - that's up to who's set up it is and what their thoughts/beliefs are. What I can say for certain is on my 15kw rotary (3600 RPM with a Honda GX690 engine) - with the fuel line/system plumbing we have it will start and run our central AC unit with very little lugging - and that is without a soft-start.
How old and how large of a unit? That can make quite a difference. My units are old, made in 2006. One 3.5 ton and one 4 ton.
 

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So at that point - what is the big deal of tuning for the fuel type? Everyone's situation is different, though.
Does frequency effect harmonic distortion? This generator holds 60Hz almost perfectly and supposedly is 5% distortion with gasoline. I'd like to be able to switch fuels in a crisis and maintain the frequency and distortion. I noticed that many dual fuel generators have high distortion, but not all. It's already tuned for one fuel type, gasoline. Really the **** thing is almost perfect on gasoline. Last year, temps were in the single digits. I really don't want to have to take the tank off and adjust for a different fuel in the conditions I saw. Really I am beginning to think this isn't a tri-fuel situation, it's either an all propane or all natural gas conversion. That is i if you want the frequency to say at 60Hz.
 

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burn off all of the fuel, then vac the tank clean at -30 vac for a few hours.
then valve in the quality lp vapor.

hard to fix when it is a mix of gasses ..
at least to get it perfect..
I can burn off the 50 gallons of fuel. No access to a method to vac tank. I may just sell these tanks and buy some new already properly purged tanks.

I am getting backfiring off these new tanks. Does that tell you anything? I read lean mixture, too much air, can cause backfiring? That didn't happen with small tanks I used for testing. Generator never backfired.
 
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