Running Propane to a Generator

marrt · Mar 5, 2012

I recently purchased a 12KW stationary backup generator. I need to connect it to my 1000 gallon buried propane tank. I want to connect this myself and have already pulled the permits.

I'm thinking of installing a T at the tank, then running a new dedicated line to the generator, which is 15' away. I think the generator already has a pressure regulator (need to check the manual). Anyone done this?

Edit: I double posted this (got interrupted). Sorry. Hopefully, a moderator will delete the first one.

grsthegreat · Mar 5, 2012

I was going to do a similar thing myself, then when i dug to find the line i found it to be the orange plastic pipe system. There was no way for me to get parts to splice into this, so i called my propane company and they came and did the work. cant remember the cost though.

Phils · Mar 5, 2012

I did this for my 10KW genset.

The only thing I did that you didn't mention was to put a pressure regulator at the tank so that the full pressure of the tank wasn't in the underground pipes to the generator. I have it regulated to 25psi, with the main intention being "lower pressure might equal less chance of a leak".

Phil

Larry Caldwell · Mar 5, 2012

If you run full tank pressure to the generator, a small pipe should be adequate. If you regulate at the tank, you may need a larger line to get adequate gas to the engine. The regulator orifice is also important.

Unregulated propane pressure varies from 60 psi to 120 psi, depending on how hot the propane is. Regulating at the tank can sometimes cause propane to re-liquefy in the lines on a cold day because of expansion. At 40 below you get zero gas pressure, because the propane just won't boil. Burying the lines below the frost zone will let them pick up some heat from the soil.

I once worked on a Ford V-8 natural gas powered emergency generator system. They moved the regulator from 100' from the genset to 300' from the genset, and a 3" line suddenly wouldn't carry enough gas to run the engine. We regulated the line to a higher pressure, then stepped down at the engine, which solved the problem.

marrt · Mar 5, 2012

Thanks for the comments. The line has to be buried at least 18" with caution tape above. County didn't mention a trace wire though.

Anyway, I'm having trouble finding the components. Permasert couplers, etc...

Egon · Mar 6, 2012

Install a regulator at the tank.

sunnyside360 · Mar 6, 2012

I installed a new Generac 17 kw standby generator a few years ago and there was NO pressure regulator inside the generator. The install guide specified regulating the pressure to 10 - 12 psi (iirc) at the generator input. I already had a 3/4" line from the tank to the house with a regulator right at the house connection (outside). I put a "T" on the main line from the tank and put another dedicated regulator on the new 3/8" line to the generator. Also, the generator was shipped with a natural gas orifice and I had to change it to an LP orifice. The generator has worked flawlessly for over 4 years.

I am not an expert in this area but I hooked up the generator exactly as the gas company recommended.

TripleR · Mar 6, 2012

My father in law owned a propane company and did thousands of propane hook ups as did my brother in law and son. He sold his business to a relative. When we built our house, he and I did all of the trenching for water and electrical, but nothing on the propane lines or hookups.

He explained that if anything happened causing a fire or explosion, our insurance may refuse to pay if it was learned the work had not been done by a gas company. We paid to have a hot water heater swapped out not long ago.

I am probably overly cautious, but just a thought.

Iplayfarmer · Mar 6, 2012

TripleR said:
My father in law owned a propane company and did thousands of propane hook ups as did my brother in law and son. He sold his business to a relative. When we built our house, he and I did all of the trenching for water and electrical, but nothing on the propane lines or hookups.

He explained that if anything happened causing a fire or explosion, our insurance may refuse to pay if it was learned the work had not been done by a gas company. We paid to have a hot water heater swapped out not long ago.

I am probably overly cautious, but just a thought.

This is where permits come in to play. If you do the work yourself but have it recorded and inspected, there should be no way an insurance company can deny your claim.

jonyyuma · Mar 6, 2012

AS in do-it your-self electric work on your new added home addition.. Things get very sticky after a fire? We had a neighbor lose his house to a fire,,< the insurance company investigated the last repairs? The HVAC mech. lost everything over the total loss after the attorneys were finished, even with him being insured and bonded?? He had replaced a fan on the central heat system, they zeroed in on the kill with a field of experts..Metalurgy exams of the ruins??