From: John De Armond
Subject: Re: Propane refueling at home
Date: Fri, 14 Apr 2000 00:52:51 EDT
> What are the pros and cons of refueling my class A motorhome 65 pound propane
> tank from my home yard tank? Seems like it should be legal as the propane is
> not used to power the RV.
Works like a champ with a couple of caveats. I do that here using a
setup supplied by my propane company. This is very common among
caterers and concessionaires (both of which we do) where a lot of
20# tanks are used. The saving is phenomenal. I pay 88 cents a
gallon for propane and a 20# tank holds a bit more than 4 gallons.
Compares quite favorably to the C-store changeout or the $8 the
local propane companies charge to fill them. :-)
What you want goes by a couple of names. It's called either "liquid
withdrawal" or "wet leg". There is no pump involved. On any
standard large propane tank, there is a liquid withdrawal valve that
is located outside the dome. If you look at your tank, you'll see
two fittings, one on each end, that are outside the dome. One
fitting is the safety relief valve. It normally has a plastic rain
shield insert. If you remove that insert, you'll see a wide open
orifice with no threads of any sort on the outlet. On the other end
will be a smaller but similar looking fitting. it normally has a
dust cap also. Under the cap is a threaded fitting and a valve that
works somewhat like the shraeder valve on your tire. This is the
liquid withdrawal line. Inside the tank is an excess flow valve and
a dip tube that goes to the bottom of the tank. This line is
designed primarily so that the propane company can pump the tank dry
before moving it. It also works great as a portable tank filling
What you need to make this work is a mating special fitting for the
liquid withdrawal port, a valve, some liquid propane rated rubber
hose (heavy, expensive), a WOG rated ball valve (gas cock) and a
male POL fitting, preferably one with the O-ring that doesn't
require a wrench.
To use, simply hook the line to the POL fitting, open all the
valves, open the 10% valve on your tank and let it fill. It usually
takes about twice as long to fill this way as it does at the propane
store where they have a pump, but then, who's counting? :-) I have
an 80 lb built-in tank on my MH and it takes about 10 minutes to
fill from empty.
One might question where the driving force comes from to make the
gas flow. It comes from many sources. If your bulk tank is full,
then ordinary siphon action will drive it, assuming your RV tank is
lower than the bulk tank LEVEL. Even with the RV tank HIGHER than
the bulk tank, the driving pressure can be developed simply by
opening the 10% valve on the RV tank. AT first blush, you might
think that opening this valve simply relieves pressure on the RV
tank but that's not what happens. The residual liquid propane in
the tank can evaporate more than fast enough to hold the pressure up
against the rather small flow of the 10% valve. What happens is the
evaporation of the propane refrigerates the rest of the propane
which lowers its vapor pressure and THAT is the driving pressure.
Another factor is, normally the bulk tank is out in the open where
it is heated by the sun. The RV's tank is under the vehicle and so
is cooler. Finally if you're very impatient or it is very cold
outside, you can heat the bulk tank. I have a heating blanket I use
for that. I've also used one of those propane-fired construction
heaters that looks like a jet engine. Again, only a couple of PSI
are necessary to force the propane flow so you need raise the
temperature of the bulk tank only a couple of degrees. If the bulk
tank is significantly hotter than the RV tank, you don't even need
to open the 10% valve until you need to check for the RV tank to be
I didn't have any luck using the ACME fill connection (where the
propane company normally hooks the fill hose) because that fitting
has an internal checkvalve that takes more force to open than the
small differential pressure this passive filling scheme generates.
I did make up an ACME fitting with a probe in it that would press on
the checkvalve and force it open once the hose was hooked up but
it's really not worth the effort. I just fill through the vapor
withdrawal POL valve.
There is no license or code requirement to do this for yourself on a
non-commercial basis. At least not a national code. The Fire Chief
could not care less here. Indeed, I fill tanks for the #1 fire
hall's BBQ grill, located a couple of blocks away, on occasion. The
only problem I ran into was having to call around to find a gas
company willing to supply me the wet leg. Some got their panties in
a wad over perceived liability. A couple were more than eager to
fix me up. The company I chose supplied all the hardware needed at
no cost and no rental as long as I fill the bulk tank once a year.
I usually have to have it filled a couple of times a summer during
peak catering season and at least once during the winter. I got
this tank ONLY for filling smaller tanks and have no regular heating
loads hooked to it. If all else fails, buy your own tank (that's
what we did at our cabin in the mountains) and let the gas companies
bid for your business.
There are a couple of precautions/situations you need to be aware
of. The first is to make sure the vented propane can't collect
around the RV. I have a squirrel caged fan removed from a furnace
that I set out a few feet away from the RV and direct its blast
across the area under the tank. This sweeps the vented propane away
as quickly as it vents.
The second item is the potential for pranksters to create a very
dangerous situation. The wet leg comes out of the tank outside the
dome so you can't lock the liquid valve like you can the rest of
'em. I've had vandals open the valve and vent some propane before.
It apparently scared 'em so bad they didn't leave it open but the
possibility is there. An open line could empty a 250 gallon tank in
minutes if the internal excess flow valve doesn't catch. What I do
is coil the hose up around the valves under the dome and then lock
the dome. I use a combination padlock and left the combination with
the propane company so that they can get in to fill the tank. I
also bought a valve locking bonnet from Grainger that lets me
padlock the handle of the valve coming out of the tank.
Next, you're venting a lot of propane and if you have an anal
neighbor, you might get the fire department called on you. Since I'm
friendly with my neighbors, I just told 'em what I was doing and if
they smell gas, to look to see if I'm at the tank doing something
before calling it in. If I wasn't friendly with 'em, I'd just tell
'em I was working on the gas system and to ignore the gas smell.
Lastly, be aware of static. The UL-approved propane hose contains
drain wires so once you hook the line up, the tank and RV are
electrically connected. But if there happens to be any static on
the RV AND either of the valves is leaking a little, you could
ignite a fire when you touch the POL fitting to the tank. It's
probably a good idea to get a length of wire with an alligator clip
on each end and bond the RV and tank together before hooking up the
Hope that helps. Feel free to ask any more questions.
From: John De Armond
Subject: Re: Refill propane
Date: Sat, 03 Jun 2000 00:47:28 EDT
G Sanders wrote:
> JOE NEAR wrote:
> > Gary:
> > The non-removable tanks have gauges and stop-fill valves that will not
> > allow overfilling. For removable tanks the tare (empty) weight is
> > stamped on the tank. All tanks I have seen have a separate small-bore
> > valve that is opened during filling. They should open that valve and it
> > will leak vapor until the tank is 80% full, at which time it will leak
> > liquid. Sort of a belt and suspenders approach. Doesn't mean they don't
> > mess up sometimes.
> Yeah. I know - we used to sell the stuff. There are two problems with the
> bleeders - (1) I've seen 'em clogged up. And (2) some REALLY old bottles
> don't have bleeders at all. THAT's why older bottles should ONLY be filled
> by weight.
> I don't know if you could get away with filling the newer OPD bottles
> without weighing. We sold our business before they were in common use.
> I doubt that the OPD devices are built as well as the stop fill valves
> on ASME tanks, so I don't believe I would trust them to work EVERY time.
> Life's too short.
I agree with your, Gary. The ONLY way I'd fill DOT tanks when I
sold propane was by weight. I saw way too many tanks with the wrong
stop fill valve (20# valve [short dip tube] in a 30# [needs longer
tube]) or valves where the dip tube had fallen loose to rely only on
that. I open the stop fill valve as a backup and to bleed any
trapped air but the scales tell the true tale.
From: John De Armond
Subject: Re: Refill propane
Date: Sat, 03 Jun 2000 18:07:33 EDT
"R.J.(Bob) Evans" wrote:
> Why can't they fill by meter, sitting on a scale? Most of the propane
> locations have both devices now. It really p***es me off when they
> have a "standard" charge for filling a bottle that is more than the
> cost of the propane even if your bottle was brand new and needed to be
> purged as well as filled.
You're paying the fixed charge for the labor involved. A 20 lb
grill tanks holds just a touch over 4 gallons of propane. When I
was in the biz, propane cost us about 70 cents a gallon. I
therefore had $2.80 in material costs. The difference between that
and the $8 we charged was to pay for someone to sit there just
waiting for a customer to amble in and then to spend 15 minutes
filling the tank. And to give me a buck or two of profit. Sorry it
annoys you for the dealer to make a profit.
As for filling by meter, the meter's not going to do you much good
if you bring a half-filled tank in to be topped off, now is it?
Filling by weight is the only safe method and is probably the
legally required method by now.
> If more RV'ers would complain about propane gouging perhaps some of
> the retailers would change their practices and make the system better
> for everyone. (Well, not better for the retailers who enjoy the
> present gouging system.)
One can always tell the people who have never been in business from
statements like this. Bob, I think you ought to scream your head
off about "gouging" and get all your friends to also. Then the
propane dealers in your area will do like all but two have done in
this area - they'll quit filling DOT tanks for customers. They'll
tell you to go to the C-store and pay $25 to trade in your grill
tank. Have a larger tank? Too bad. You'll have to find someone
with a truck to haul the tank to wherever there is a filling
station that still does it because it is now illegal for a dealer
to fill a tank that is to be hauled in a car or closed van.
Let me give you a clue, Bob. Dealing with walk-in customers is a
distracting sideline for most dealers. The guy with the goosneck
trailer holding 100 forklift tanks who came at a scheduled time each
week from a nearby factory? I LIKED him. But I did retail customer
fills as a courtesy since I was the only dealer that did that on my
end of town. I was also the only dealer in town who would fill
motorhomes. Nobody else wanted to fool with 'em. It was me or the
KOA way out on the interstate.
So bitch right away, Bob. You'll enjoy the gouging you'll get when
you have to go to the local C-store to get your propane.
From: John De Armond
Subject: Re: Refill propane
Date: Tue, 06 Jun 2000 12:59:09 EDT
> In article <firstname.lastname@example.org>,
> "Mickey Mathena" <email@example.com> wrote (in part):
> >I'm with you Dave. I've never even seen a scale here.
> Back in the dark ages some propane tanks were made without
> 20% valves (they were called 10% valves back then) and the only
> way they could be legally filled was by weight, because scales
> were considered more accurate than meters back then. Other than
> a bunch of 25 gallon tanks that we used with the space heaters
> we rented to the contractors it was rare to see one of these and
> our meter was accurate enough that if we were feeling rushed we
> could fill our tanks by meter without getting over-filled tanks.
That works until someone brings in a tank that is not completely
empty. Then your procedure overfills it. which is why your
procedure is illegal and has been for a long time.
The procedure of using only the 20% valve also fails when a) the dip
tube is gone or b) when the wrong valve is fitted. I saw a
significant amount of both at my store. Some cheap valves have the
dip tube pressed in. When the press fit loosens, the tube falls
out. Even those that are silver soldered can break at the joint
from fatigue due to vibration.
The only reasonably safe and legal method of filling DOT tanks is by
weight. End of story. If you're a dealer and are not filling by
weight, you're violating DOT rules and you're probably also
violating the terms of your filling station lease (assuming you're
leasing it from a gas company) and the terms of your insurance
policy. If you're a customer who knowingly accepts a tank filled in
this manner and an accident happens, you're also liable. Since
you've read this post, you now know. You may also be violating DOT
rules (not sure on this one) by transporting a tank filled in this
manner over public roads. DOT very seldom enforces against
individuals but if you're involved in an incident, this is just
another charge they can pile on.
Frankly, the attitudes displayed in this thread are exactly why OPD
valves are being forced down our throats. The OPD valve will
convert propane tanks from their present stone-cold reliable,
never-thought-about condition to finicky, picky and unreliable
devices. The excess flow orifice also required to limit flow to no
more than 120,000 BTU will make it impossible to burn large burners
like weed burners and construction heaters from these tanks. The
world just got more complicated and only because a few IMHO very
stupid people refused to get with the program of proper and safe
tank filling. Way to go, guys.
From: John De Armond
Subject: Re: Refill propane
Date: Tue, 06 Jun 2000 16:47:37 EDT
> In article <393D2DDC.5E8E7680@bellsouth.net>, Neon John
> <firstname.lastname@example.org> wrote (in part):
> >That works until someone brings in a tank that is not completely
> >empty. Then your procedure overfills it.
> Huh? On our own tanks I knew the tare weight stamped on the
> tank was accurate, if I couldn't get these tanks filled right I
> certainly wasn't qualified to fill the hundreds of other tanks I
> was filling. As these tanks often sat in the fill shed for days
> at a time we'd have quickly spotted it if one of the guys was
> over-filling tanks.
You said that you filled tanks using the meter when you felt
rushed. That procedure absolutely WILL overfill a partially full
tank brought in for topping off. Doing it by weight using the tare
weight stamped on the cylinder neck is the only correct way to do
> I would like to know how you plan to fill my mounted tank on
> the motorhome by weight? Best I can figure out is read the crude
> little gauge on the tank, tap it and hope the damn thing is
> reasonably accurate and aint stuck, watch the 20% valve and go
> for it. A reasonably well educated motorhome owner should be
> able to figure out if this didn't work and what to do about it
> if it didn't. This certainly works better than the pump until it
> won't pump no more procedure that resulted in most of the over-
> fills that I saw.
Permanently mounted tanks aren't DOT tanks and the rules are
different. The correct way to fill these is to use the stop-fill
vent which does not rely on a dip tube and is instead positioned at
the correct place on the cylinder. One bills the customer by the
gallon in this case but fills to the stop fill vent.
> And I say all this knowing that the vast majority of RV
> owners aren't properly educated in the safe handling of propane.
> My personal opinion is that if you don't know the proper
> procedure for fillin' yer' tanks, you owe it to yourself to take
> your RV to a propane plant that will fill it and have them
> educate you. (And I've said that here several times John.) The
> plants that will fill RVs do it as a form of advertising and are
> happy to educate people for free. I have been there and done
> that many times, our best customers were the ones who know what
> in the hell was goin' on.
There again, though, it's buyer beware. That guy you talk to at
the propane dealership may be one of those minimum wage guys who was
pumping septic tanks on his last job. The way to be sure is to get
a copy of the NFPA national propane code. If you can find the
licensee (that is the key) at the dealership, he will usually know
at least a few of the rules and he will probably provide you with a
copy of the relevant parts of the code. At least in Tn, the
licensee has to attend a day long "college of propane knowledge" in
order to be licensed. I went and thought it to be a decent course.
Tennessee's kinda touchy over propane, being the home of the epochal
event in propane safety history - the Waverly BLEVE that killed
scores of people. A propane truck had been hit by a train in
downtown Waverly and set on fire. People were allowed to remain in
the area to watch and when the tank BLEVE'd, it killed a huge chunk
of the onlookers. Caused a national re-examination of both propane
safety and emergency management practices. Especially so in Tn.