Blowing through propane

[Cate&Rob]

Most places will release the air and fill the tank all the way, so you get 20#

We should probably clarify a few things WRT propane tanks . . .

There is no air in a propane tank. All air is purged out in the initial tank filling process because air and propane together inside the tank could create a combustible mixture. When the referenced valve is opened, what is coming out is raw propane vapor. Use of this valve is not permitted in some jurisdictions. See "spit valve" discussion below.

A propane tank can be filled with liquid propane to 80% of its total volume. This is a "full" tank. The remainder of the space will be filled with propane vapor and must be there for safe expansion of the liquid propane with temperature change. All modern removable propane tanks have a float that shuts off the fill at 80% liquid level (the OPD or Overfill Prevention Device).

Before the OPD, there were two ways of knowing when the tank was 80% full of liquid. One was by weighing the tank and its contents. (Thus a "20 lb" tank or a "30 lb" tank) For tanks too large to weigh or perhaps permanently mounted in a vehicle, there is a "spit" valve with a tube inside the tank to the 80% level line. The process used to be to open this valve, releasing propane vapor until the liquid level reached this tube and liquid propane would begin to "spit" out this valve. Obviously either of these fill methods is highly dependent on the person doing the filling to stop the fill at 80%. . . . thus the development of the OPD for a more reliable fill to 80%.

Agreed that "exchange" propane tanks are usually filled to less than their allowable 80% or 20 lbs of propane. I presume that this is done for an extra level of safety WRT temperature expansion.

Rob

[bertschb]

Thanks for sharing this information Rob

When I get my 30# tanks filled in California at the local U-Haul, they no longer utilize the "spit valve" when filling. They put the tank on a scale then start filling it. I've noticed the flow stops automatically when it gets to around 7.0-7.1 gallons. Now that you've explained the OPD valve I understand why the fill stops with no intervention from the attendant. I have no idea why they put the tank on the scale because they ignore it until the flow stops.

[OffToHavasu]

Now there's a perspective from California LOL!.

Let me tell you about testing cars at -40 (C or F) in northern Canada . . . but, I digress . . .

Rob

When it's time to visit my wife's sister in Omaha,NE during the Christmas break, I kiss my wife and kids good-bye and say, "Have a good trip."

[BarberArias]

Fixed the propane problem! Just get bigger tanks and you don't have to fill them as much!

[ThePowells]

That will work!

[mattyD]

Must be normal. We've blown through a 30# tank in 4 nights and it's only in the upper 30's, lower 40's outside. We too used our electric fireplace to help with propane usage. Uses too much IMHO.

[howson]

Must be normal. We've blown through a 30# tank in 4 nights and it's only in the upper 30's, lower 40's outside. We too used our electric fireplace to help with propane usage. Uses too much IMHO.

MattyD--noted that was your first post so just a quick "Hi" and an invitation to check out the Welcome Letter to New Members https://gdrvowners.com/forum/main-fo...to-new-members

Howard

[Jims94vmx]

Another area to check is behind your wall underneath. I was messing around with the heat ducts and basically noticed no difference when restricing flow to the bathroom and tank runs....I was trying to get more hot air to the island.

While heat was running I went back into the pass through and noticed how Hot it was.......the small register on the ceiling was barely coming out so why was it that hot?

Dug deeper and found all kinds of hot air coming up from floor where plumbing went through.....must be a channel for the island. I am guessing that the furnace has heat coming out of the bottom where it attaches to the floor through this channel and into the island. (Correct me if that is not correct).

I used foil tape to seal off the floor and seemed to help the flow to the island......

Not sure how to access this under floor area to see, but a lot of heat was coming up from this hole!

[ThePowells]

I also feel that my basement is too warm. I had a remote thermometer down there (front basement)and the temps were almost even with the upstairs and I can feel the heat when I open the rear storage. Another dragon for another time.