Any propane experts on here?

NM_Shooter · December 04, 2012, 09:57:23 AM

When filling my 20# bottles, I have been told that filling above 80% is now prohibited by law.

I've done a little looking around on the web, and it appears that the DOT and NFPA folks have conspired somewhat to require all new bottles in the consumer range to be fitted with overflow protection devices, or OPDs. These are used to prevent "overfilling".

However, I can not find any code requirement or description of what "overfilling" means.

Can anybody point to a document on the web that defines what overfilling might be, or is this just a nebulous concept? Who defines what overfilling is?

MountainDon · December 04, 2012, 10:59:39 AM

The tanks have always been over filled if filled beyond the 80% amount. The tanks have always had a "bleeder" valve that IF used vents liquid propane when the level hits 80%. There is a dip tube that extends down to the 80% level. If the valve is closed it is possible for the supply pump to overfill the tank. Some dealers would. That's why the OPD valve was invented; to prevent dealers from going over 80%. It's limited to 80% to keep the over pressure valve from discharging when a cylider gets heated on a hoy summer day.

At least that is my understanding.

December 04, 2012, 11:46:07 AM

I'm guessing that the tanks turn into a "wet leg" if overfilled?

The reason that I am asking is that I was told that ACE Hardware has a habit of filling the tanks more completely... almost to 100% of capacity (before the OPD devices).

I was trying to find something on the web that indicates what these levels are, and why it is "code" to not fill completely.

MountainDon · December 04, 2012, 01:19:31 PM

Liquid propane expands much more with temperature change than water. Seventeen percent more. That's why it's important to leave space. The 80% is based on 60 F. The metered pumps have a temperature / volume compensation device built into them.

NM_Shooter · December 04, 2012, 04:17:20 PM

I learned a ton about propane today

This also makes me a little suspicious of the place that I purchase propane.... Ortega's on 2nd street. I am going to watch them much more closely when they fill.

December 04, 2012, 05:58:47 PM

They do use a scale whenever I've been there. That's the official approved method of judging the refill amount. Next is filling to when the bleeder spits liquid. That is used mainly for a new tank to purge air / moisture from the tank. The OPD is supposed to be used only as a safety device. Also apparently if the dealer uses the OPD as his usual way to tell a tank is full, the rapid shut off can damage their pump over a period of time. So I've been told.

My tanks are always dead empty; if they were partial I'd ask for the weight they added. They are still cheaper than any other dealer I've tried. If you note any hanky-panky it would be good to know.

Huge29 · December 05, 2012, 01:26:09 AM

My cabin has the buried 1,000 gallon tanks, which is four years old. The gauge goes to 1,000, but is always filled to 850 or 85% every time we refill. I don't know if the mechanism varies from a 20??

Native_NM · December 05, 2012, 10:53:46 PM

I go to the RV dealer and they use the scale.

roadtripray · December 13, 2012, 09:42:42 PM

Around here, the most prevalent cylinder-exchange service is a company called Blue Rhino. This is where you go to a home improvement store or supermarket and swap your tank for a full one. Blue Rhino, however, only puts 15# in a 20# cylinder, and they run about $21.99 or so, depending on the store.

I take my cylinders to the KOA campground in Fort Mill and they fill my cylinders with 20# for $19.99. 33% more fuel for $2 less.

Right now I am living full-time in my RV, so I can burn a lot of propane in the wintertime, so making the most of my propane dollar is very important!

Peace,
Ray

December 13, 2012, 11:12:11 PM

While travelling around we had a couple of vendors that overfilled the old style tanks and there were a couple of trips when they popped off in the sun. It wasn't a big deal in the open but it sure gets your attention. I'd hate to have one venting around the house or camper. which does get around to, when you mount the regulator from a big tank on the house pay attention to where the vent on the regulator is, we have attached a pipe to get any vented gasses away from windows, motors, intakes and hot exhausts. Mechanicals tend to line up on one side of the house and that regulator is often in the cluster.