PROPANE: What´s happening?

SantiagoDR

SantiagoDR

The "REAL" SantiagoDR
Jan 12, 2006
5,812
950
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I noticed lately that my mileage in the car has dropped significantly.

Yesterday I filled up the propane tank in the car, it was about 3/4 empty at the time.
Today there was a problem and the engine quit.

My thoughts were that there was too much air in the tank and it was possibly a vapor lock.

So, with a "Full" tank I decided to let some of the air out until I saw the familiar freezing mist of propane. That mist NEVER occurred. I then realized that the same familiar mist had not been happening as much when the attendant removed the nozzle after filling the tank (I always get a complete fill-up).

Also the"air" escaping from the tank was no longer super cold, it was chilly but not the normal freeze your hands off cold. And this was from a full tank of propane. The fuel gage dropped significantly and yet the escaping "fuel" still was not the freezing cloud of propane.

Upon returning home, I tested my recently filled 12 gallon(?) spare tank used for the stove. (I like being prepared for propane running out). Same thing, no propane mist, only chilly, not freezing as it normally would be. The car and spare tank were filled at different propane stations. I do not know if the propane stations were the same brand or not. My mechanic was test driving the car after doing some repairs and I told him we were running low on fuel, so we went to a station near his shop.

Even the valves on the tanks were not very cold, which are usually extremely cold when this operation is performed.

Why would the escaping pressure not be freezing cold as usual?
With a full tank, the escaping propane should have been freezing cold pretty much immediately.

Are we being ripped off at the pumps or is there another explanation?
 
T

Tashi Siu's Dad

Gold
Jan 7, 2016
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Have you given any consideration to water infiltration into the supply you filled from or your own propane storage tank? Water vapor will cause the problems you are experiencing. With all the rain, flooding, etc. that is happening right now, maybe the propane was contaminated, either at the source or in your storage containers.
 
Hillbilly

Hillbilly

Moderator
Jan 1, 2002
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My take on this:

There is "somebody's Law" that says the simplest explanation is probably the right one.

In this case I would say you are getting gypped. Just sayin'....

HB
 
SantiagoDR

SantiagoDR

The "REAL" SantiagoDR
Jan 12, 2006
5,812
950
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Hillbilly said:
My take on this:

There is "somebody's Law" that says the simplest explanation is probably the right one.

In this case I would say you are getting gypped. Just sayin'....

HB
Click to expand...

That´s my opinion also.

Since when is escaping propane not freezing cold?

I have 3 different tanks, filled at 3 different times, at 3 different stations.
None of them is freezing cold or do I see the "mist" when I open the valve and let the "GAS" out.

I get the feeling they are mixing the propane with something else before we buy it.
(That of course is after they add the usual air to it)


A few weeks ago I had a slow leaking connection in the car, in the morning there was a pile of ice in the trunk, and a strong odor of propane. This new stuff I barely smell when it is coming out of the tank.
 
B

banzai

Member
Aug 16, 2013
152
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18
some thoughts...it would be very difficult to "pump" air into a purged propane tank and have the gauge register since the gauge relies on "liquid LP" vice a vapor...which brings me to the next thought, there is considerable difference in temperature when releasing LP - vapor will normally be ambient temperature +/- while liquid will be around negative 40F. You normally will not "see" vapor but liquid LP will appear as white cloud. A possible explanation could be that the donor tank (pumping station) was very low on product and that the odorant (in its pure state LPG is odorless/colorless like LNG) that is added to LP accumulated to the point where you received the "dregs"? The odorant and LPG are similar in property weights and pressures but do tend to separate when not agitated - such as refueling or refilling. If your vehicle is running LPG through a water heated regulator it may be necessary to detach and clean the output section of the regulator as a buildup of the odorant could cause loss of power and/or complete shutdown of the engine in extreme cases. This residue will resemble a fairly thick motor oil which really "stinks"; try not to get it on your hands or any clothing you wish to continue wearing! Good luck...
 
R

reilleyp

Well-known member
Dec 12, 2006
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I do not know anything about propane, but now you have stirred my curiosity. After doing a little research, maybe you want to weigh your tank before and after filling, assuming it is not too much trouble to remove the tank. From what I read;

Propane weighs about 4.24 lb per gallon, so 4.6 gallons is 19.44 lbs.

If the tank is underground at a lower temp, you should have more volume as it warms up to 90 degrees.

Gasoline and water both weigh more. Gas is about 6.3 lbs per gallon. Water is about 8.34. If you are getting more lbs than you paid for, maybe you are getting some water in with your propane?

I am curious to find out what happened. Keep us posted please.
 
chico bill

chico bill

Dogs Better than People
May 6, 2016
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Do the LP tanks have a drain valve. If so run the car to empty then drain the tank and if you have a way to introduce a little metyl alcohol to absorb the water then drain that and then fill full with quality gas. But this does not seem to be your problem.

I have always been leery of gas vehicles although I used to have an old International pickup that ran on it. Hated that truck.

Sent from my HTC One A9 using Tapatalk
 
PICHARDO

PICHARDO

One Dominican at a time, please!
May 15, 2003
13,280
893
113
Santiago de Los 30 Caballeros
SantiagoDR said:
I noticed lately that my mileage in the car has dropped significantly.

Yesterday I filled up the propane tank in the car, it was about 3/4 empty at the time.
Today there was a problem and the engine quit.

My thoughts were that there was too much air in the tank and it was possibly a vapor lock.

So, with a "Full" tank I decided to let some of the air out until I saw the familiar freezing mist of propane. That mist NEVER occurred. I then realized that the same familiar mist had not been happening as much when the attendant removed the nozzle after filling the tank (I always get a complete fill-up).

Also the"air" escaping from the tank was no longer super cold, it was chilly but not the normal freeze your hands off cold. And this was from a full tank of propane. The fuel gage dropped significantly and yet the escaping "fuel" still was not the freezing cloud of propane.

Upon returning home, I tested my recently filled 12 gallon(?) spare tank used for the stove. (I like being prepared for propane running out). Same thing, no propane mist, only chilly, not freezing as it normally would be. The car and spare tank were filled at different propane stations. I do not know if the propane stations were the same brand or not. My mechanic was test driving the car after doing some repairs and I told him we were running low on fuel, so we went to a station near his shop.

Even the valves on the tanks were not very cold, which are usually extremely cold when this operation is performed.

Why would the escaping pressure not be freezing cold as usual?
With a full tank, the escaping propane should have been freezing cold pretty much immediately.

Are we being ripped off at the pumps or is there another explanation?
Click to expand...




This is not rare...
It happens depending on the batch dispatched to retailers. Sometimes the vapor density is just crap and you’ll end up with a very low quality output.

You can make a complain to the DR regulators about it. They have a tool for that and a trained guy to read it and interpret the readings.
It’s as you said, exactly! The best way to notice it, is when you use it to cook on the kitchen. The flames will always turn yellowish and leave a nasty black film on the bottom of cooking pots or frying pans. Some people spend useless cash in trying to repair a perfectly working range, by re-adjusting the air and flow on their appliances, only to see it reoccurring once the tank is empty and a new one without the crappy gas is tapped into.
 
E

ExDR

Member
Jul 31, 2014
421
0
16
rubio_higuey said:
I noticed the same thing about mileage but it needs further testing.
Click to expand...

You should not be getting ripped off when buying propane with a portable tank. Most tanks are filled by weight, if they are using a volume counter to fill (as in cars) they can easily fill the station tank with pressurized air to make it seem that you are getting propane when all you are doing is getting tour tank filled with air, much like a scuba tank. You can test this by weighing your empty propane tank and then getting it filled. It should weight about 20 lbs filled. Air does not weight anything.
 
cobraboy

cobraboy

Pro-Bono Demolition Hobbyist
Jul 24, 2004
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ALWAYS require the attendant to open the air valve while filling! This allows moist air to escape and ensures a complete fill.

That moist air WILL condense sooner or later and give you water in the tank.
 
P

PJT

Silver
Jan 8, 2002
3,564
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Propane butane mix ratios.

Most likely the problem is the mix of propane and butane. Ideally, the mix is 60% propane and 40% butane. It burns cleaner and is more efficient. The Propane Gas Dealers say the Consumer Protection Agency had an erroneous reference of 90% propane and 10% butane. The government standards are supposed to be 70% propane and 30% butane. That mentioned, it appears the more propane in the mix brings less economy. Suspect the mileage drop could be a result of a change of mix to a lesser amount of butane. Butane cost more than propane. You can arrive at your own conclusions.


Regards,

PJT
 
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