Filling Butane to 80%

[ScottyBye]

Originally Posted by curtsr

The propane gauge in my 2016 Phaeton is calibrated to 100% gauge reading when the tank is physically 80% filled with liquid, which also agrees with the gauge in the coach. Since the tank is located horizontal their is adequate vapor space. We always fill to 100% gauge reading without any problems.

Originally Posted by twinboat

My gauge is not calibrated like that.

The fill vavle shuts down and it spits gas out the vent, when the gauge is around 3/4, outside and in.

There doesn't seem to be any adjustment, to change it.

This is pretty standard and normal.

[select55]

Originally Posted by curtsr

Reading this conversation implies that you stop filling the propane tank at 80% on the gauge. The propane gauge in my 2016 Phaeton is calibrated to 100% gauge reading when the tank is physically 80% filled with liquid, which also agrees with the gauge in the coach. Since the tank is located horizontal their is adequate vapor space. We always fill to 100% gauge reading without any problems.

horizontal or vertical 80% is 80% but the correct gauge stetting is when the gauge reads full when filled to the 80 % level both on the tank and on the remote read out

[curtsr]

Disagree with 80% is 80%. This would only be true if you were measuring volume, however the gauge reading is level in height. Therefore the vapor space is larger in a horizontal tank when filled to 80% level than a vertical tank. Unless maybe the tank is a sphere.

[twinboat]

Originally Posted by curtsr

Disagree with 80% is 80%. This would only be true if you were measuring volume, however the gauge reading is level in height. Therefore the vapor space is larger in a horizontal tank when filled to 80% level than a vertical tank. Unless maybe the tank is a sphere.

That sounds like fuzzy math. They are reading volume. 80% is 80%.

The vapor space is wider but thinner.

[twinboat]

Originally Posted by select55

horizontal or vertical 80% is 80% but the correct gauge stetting is when the gauge reads full when filled to the 80 % level both on the tank and on the remote read out

So, are you saying I am wrong ?

Am I, along with the filling attendents, somehow miss-reading my gauge, when the tank stops filling and the needle is pointing at 3/4 ?

[ModestMonk]

Originally Posted by twinboat

That sounds like fuzzy math. They are reading volume. 80% is 80%.

The vapor space is wider but thinner.

When you look at 1000 pound or 500 pound bullet tanks the idea is that there's more surface area within the tank to allow the conversion from liquid to vapor. These are normally used to supply devices that need to be replenished constantly.

[twinboat]

Originally Posted by ModestMonk

When you look at 1000 pound or 500 pound bullet tanks the idea is that there's more surface area within the tank to allow the conversion from liquid to vapor. These are normally used to supply devices that need to be replenished constantly.

Sure, but that's because 20% of 1000 gallons is twice as much as 20% of 500 gallons. Its still 20% of the volume, used as head space, when full.

[ModestMonk]

Originally Posted by twinboat

Sure, but that's because 20% of 1000 gallons is twice as much as 20% of 500 gallons. Its still 20% of the volume, used as head space, when full.

[select55]

Originally Posted by twinboat

So, are you saying I am wrong ?

Am I, along with the filling attendents, somehow miss-reading my gauge, when the tank stops filling and the needle is pointing at 3/4 ?

no your not misreading just your tank float is set wrong. most LPG tank makers set the the 80% mark as the full mark its at its legal fill mark
I sold and installed LPG tanks for years and that the way it is
I have a 2008 allegro bus and when the tank is filled to the legal 80% mark
my gauge reads full as its supposed to

[select55]

Originally Posted by curtsr

Disagree with 80% is 80%. This would only be true if you were measuring volume, however the gauge reading is level in height. Therefore the vapor space is larger in a horizontal tank when filled to 80% level than a vertical tank. Unless maybe the tank is a sphere.

look if u have a 75 gallon tank it takes 60 gallons to fill it to legal fill mark
it matters not if you lay it down or stand it up it still has 60 gallons
that means you have space for 15 gallons
if you stand up the tank or lay down the tank it will still take the same 15 gallons to fill it full. so my point is its takes 3465 cubic inches to accept a 15 gallon volume no matter if its vertical or horizontal

[firedoc]

Does surface area of the exposed fuel come into play?

[twinboat]

Originally Posted by select55

no your not misreading just your tank float is set wrong. most LPG tank makers set the the 80% mark as the full mark its at its legal fill mark
I sold and installed LPG tanks for years and that the way it is
I have a 2008 allegro bus and when the tank is filled to the legal 80% mark
my gauge reads full as its supposed to

I think MOST is a pretty broad statement.

There are hundreds of post in RV forums claiming that their tank gauges read 3/4 when the tank is full.

" SOME LPG tank makers " would be a better statement.

[Gary RVRoamer]

Worthy of mention certain dealers fraudulently substitute butane for propane.

There is nothing "fraudulent" about that. You are buying LP (Liquified Petroleum) gas, not "propane" or "butane". In warmer climates, the LP blend typically contains a higher percentage of butane because that performs better at higher ambient temperatures. Butane-rich LP, however, may not work well if you move to a cold climate because it doesn't vaporize as well at low temps. The bottom line is that the LP blend is a regional difference, not malfeasance on the part of the retailer.

[ModestMonk]

Originally Posted by ModestMonk

Worthy of mention certain dealers fraudulently substitute butane for propane. Something I had never heard of until reading it here on iRV2.

*snip*

The whole quote says propane not LP. Taking it out of context is serving the wrong side of the issue. Substituting butane while selling "propane" is an issue.

Selling soy milk as cows milk is an issue. I don't mind your qualifier if you had noted if it's advertised as LP.