20lb Propane tanks - Can you fill from your home tank?

[RalphVa]

Makes lots of sense if it works well, e.g. without leaks. Propane is dangerous stuff to work with. It's heavier than air and can pool at your feet or other low spots.

Ralph

 

[Tractor Seabee]

Some missing information on this scenario:

Currently all portable tanks and mobile unit installed frame mounted tanks are required to have a float operated shutoff built into the fill valve that theoretically shuts off the incoming liquid when the float reaches the level required to provide the expansion space. When I had a motor home that always how fuelers did it. With the portable tanks that safety feature has been known to fail and tanks overfill. Everywhere I get tanks filled they always use the vent valve as a backup to the float. Many times I have heard the float close at the time liquid appears at the vent. It's again all about liability.

The safest way to fill small tanks from larger tanks is to put the small tank in an ice bath and let the vapor condense in the smaller tank. I guess you call me a risk taker but I scrounged up what I needed to fill on the liquid phase from salvaged MH tanks. Buy them for 50.00 at the junk yard, drain them into small tanks at up $100 worth propane and then sell the empty tank for up to $300 depending on condition. I now have a tank set up to dispense either vapor or liquid when I found a salvage tank that was a truck fuel tank that used propane in the liquid phase. There is a lot to this story I am will not tell about; for your safety. Those inclined like me can figure it out like I did.

Ron

 

[Industrial Toys]

I just want to know why the reused torch tanks leak. I think the Schrader valve is not reseating. I don't really care about the other valve as I can keep a torch head screwed on there, and keep it shut off, obviously.

 

[Tractor Seabee]

I just want to know why the reused torch tanks leak. I think the Schrader valve is not reseating. I don't really care about the other valve as I can keep a torch head screwed on there, and keep it shut off, obviously.

Maybe they are purposefully made to fail to prevent refilling. I have never used them much so never noticed.

Ron

 

[Sodo]

I致e always unscrewed it and vented the center valve. Good tip in never disturbing that external schrader valve.

 

[Industrial Toys]

That could be, but a rather dangerous way of disuading someone. The guys on Youtube don't have my problem it seems.

I had pretty much zero luck before I started using the Schrader valve in getting much liquid into the tank. Froze receiving tank, used new BBQ tank upside down, what else is there?

 

[aczlan]

Ive heard that venting is pretty moronic because a clothes static spark can ignite LP vapor which is many times more combustible than gas. And again ive never seen a professional vent a tank while filling and I've had hundreds of tanks filled.
Not trying to be an *** im just wondering what the real deal is on venting

I sit through propane tank filling training every year for filling forklift size propane tanks. Bleeding the vent is how the guy who comes in has trained us to do it every year. We run forklift size cylinders at and fill through the liquid port. There is no overfill shut off on them like there is on a BBQ tank, so you have to bleed them or hope that the gauge is accurate (it rarely is).

Aaron Z

 

[islarama]

Hey thanks. The lack of pump is exactly what I was missing. Makes perfect sense. Also interesting info for the rest of you thanks for all of it. Give me some lacking confidence

 

[rangerfredbob]

Apparently probably different on BBQ tanks versus liquid withdrawal tanks as well, at work I run engines off of the tanks I fill (forklift size tanks to a 100 gallon RV tank) so that's my most experience... the forklift and RV tank have overflow valves on the liquid outlet but the fill port is a large one way valve then you open the vent until liquid shows and it's full. The gauge on the forklift tanks are useless, they're a switch mostly and flip at around 50% but the big tank is a normal float...

But still the vent will vent liquid when the tank is at the safe full point no matter what you are filling. The vapor isn't as scary as you are thinking, no smoking, ground yourself before filling and you are fine... Sure propane is heavier than air, but unless you are in a hole or in a boat (not coast guard approved...) really not an issue. The amount of propane vented while filling even when it gets full and liquid comes out is very little...

gasoline tanks vent to atmosphere when you fill them, are you scared of getting gas in your car?

 

[aczlan]

Apparently probably different on BBQ tanks versus liquid withdrawal tanks as well, at work I run engines off of the tanks I fill (forklift size tanks to a 100 gallon RV tank) so that's my most experience... the forklift and RV tank have overflow valves on the liquid outlet but the fill port is a large one way valve then you open the vent until liquid shows and it's full. The gauge on the forklift tanks are useless, they're a switch mostly and flip at around 50% but the big tank is a normal float...

As I understand it, the dip to for the vent in a barbecue tank is at the same percentage full as it is in a forklift or other larger tank.
We fill our forklift tanks through the liquid withdrawal port. That way, the guys are forced to shut off their forklift and cannot leave it running while they fuel up.

But still the vent will vent liquid when the tank is at the safe full point no matter what you are filling. The vapor isn't as scary as you are thinking, no smoking, ground yourself before filling and you are fine... Sure propane is heavier than air, but unless you are in a hole or in a boat (not coast guard approved...) really not an issue. The amount of propane vented while filling even when it gets full and liquid comes out is very little...

That has been my experience as well. There is a reason why propane filling stations are outdoors in the open air.

gasoline tanks vent to atmosphere when you fill them, are you scared of getting gas in your car?

I suspect, that holding a lighter near a gas tank opening at the end of filling a tank would be more dangerous than holding a lighter near the vent on a propane tank at the end of filling it.

Aaron Z