Propane tank life span

[bkahler]

I was looking at some of the pictures I had taken from under my Argosy MH and after reading the ID tag on the propane tank I noticed that it has "YR 1993" engraved on it. This got me to wondering if the 1993 date refers to the date the tank goes out of certification.



I would really hate to try and find a replacement tank.

Any thoughts or suggestions?

Brad

[Aage]

Up here they need to be recerted with a new valve every ten years. The date is stamped into the top metal ring, and when recerted a new date is added.

Here, that amount of rust would not pass. The station filling is also charged with inspecting at every fill-up and refusing to fill if a lot of rust is present.

[Keyair]

Originally Posted by Aage

Up here they need to be recerted with a new valve every ten years. The date is stamped into the top metal ring, and when recerted a new date is added.

Here, that amount of rust would not pass. The station filling is also charged with inspecting at every fill-up and refusing to fill if a lot of rust is present.

Oh, crap....
Always something...
Thanks for the input Aage...

[bkahler]

Originally Posted by Aage

Up here they need to be recerted with a new valve every ten years. The date is stamped into the top metal ring, and when recerted a new date is added.

Here, that amount of rust would not pass. The station filling is also charged with inspecting at every fill-up and refusing to fill if a lot of rust is present.

I was afraid this was going to be the answer. The Argosy spent most of its life in Maine or somewhere along the east coast. I probably should add the cost of a replacement tank, about $500 based on searching this evening, to my list of needs before this thing hits the road.

Bummer...

[Keyair]

Found this...

There are two types of propane containers, the ASME tank and the DOT cylinder. NFPA pamphlet 58 states that all DOT cylinders need to be recertified after 12 years from the manufacturing date and depending on what certifying method is used they are recertified every 5,7,12 years thereafter. Recertification involves a periodical documented inspection and testing of the cylinder to confirm that the cylinder is still safe and legal to remain in service.
ASME tanks do not get recertified. They should have the relief valve replaced every 10 years and follow the same standards established by the Dept. of Transportation.

[Keyair]

New Acme valve for RV propane cylinders
& cylinder recertification



New valve for propane cylinders

The Federal government will prohibit the sale and use of POL valves found on most older DoT type propane cylinders. (POL is an abbreviation for Prest-O-Lite, for the company that first produced the valve). These valves have the familiar female left-hand-thread in the valve and are the type most of us currently have. Cylinders with this type valve may not be sold beginning in the year 2000, and may not be refilled beginning in 2002.
The old POL valves are being replaced with a new Acme type which uses a QCC (Quick Closing Coupling) connector. This connector has an external (male) right-hand thread on the valve. A pigtail hose can be connected and disconnected by hand... no wrench required. These valves also have the old-style POL internal left-hand thread, so they can be used directly in place of the old valves without modifying your RV. If you like the no-tools convenience of new style connector you may want to replace your pigtail hoses with new ones having the QCC connectors.
The new ACME or QCC valve also contains an OPD (Overfill Protection Device). So you may find them called ACME valves, OPD valves or QCC valves, depending on the supplier. The OPD feature prevents accidental overfill of the cylinder. An internal float mechanism shuts off the valve when the cylinder is 80% filled. The 20% empty space is necessary to prevent the cylinder from venting large amounts of propane when the temperature rises. (ASME type cylinders in most motorhomes have had this OPD feature for many years). The new OPD valve also contains another safety feature - it will not release gas unless the pigtail hose is properly connected, even with the valve open.

POL Valves


The old-style cylinder valve is known as a POL valve, named for the manufacturer that devised it. You tighten the connector of the regulator pigtail by turning the fitting counter-clockwise, and you usually need to use a wrench to make the connection tight enough to prevent leaks. With a POL valve, if you open it with no fitting attached, propane is freely released. That's why a plug is required to be screwed into the valve during transport of the cylinder and when it is stored or not connected to your RV. The plug is an attempt to prevent an accidental opening of the valve from creating a dangerous situation. This valve also has a built-in bleeder valve the service technician uses to check for proper filling and a pressure relief device to prevent over pressurization of the cylinder.

ACME Valves This valve is also known as QCC (Quick Closing Coupling) or OPD (Overfill Protection Device) The New ACME valve looks bulkier because there are external threads visible. The external threads don't necessarily require a change to the connector on the end of the regulator pigtail hose. They are compatible, as the left-hand-thread fitting on your RV regulator will screw into the internal POL threads of the new ACME valve. However, one of the benefits of the new connector is that it is designed to be attached to the cylinder without tools. You only have to hand-tighten the connector. And, you tighten as you would normally tighten a threaded fitting, by turning it to the right (clock-wise). So at the cost of a few dollars it may be good to replace the pigtail hoses.

Propane Cylinder Recertification

If you have an older RV you should know that according to Federal law, DoT cylinders may only be used for 12 years after their manufacture date. After that, the cylinders must be "recertified" which provides another five years of use. The cylinders can be recertified every five years thereafter.
However, because your old cylinders no doubt have the old POL type valves, you will effectively only have two more years of use since these cylinders may not be refilled after 2002. It may well be cost effective to buy new, compliant cylinders, rather than go to the trouble and expense of getting your old cylinders recertified. This is especially true with the smaller 20-pound cylinders. Check with your propane dealer and compare costs.
Propane dispensers are legally required to look at the date stamped on the cylinder before filling it. Some dealers actually do look. We've been reminded a few times that our cylinders were about to expire. Check the date stamped on your cylinders... don't rely on your rig's model year even if the cylinders are original. It's quite possible they are a year or more older than your rig. Ours were.
Recertification is usually done by the large bulk propane suppliers but we found one of our local RV repair shops was certified to do the job and they do it for free! Call around to see who may do it in your area.

[slowmover]

They can last a reeaallly long time

Chemistry Blog » Blog Archive » Nazi Paraphernalia in Lab

[idroba]

The motorhome tanks do not require recertification here in the US. (may not be true in Canada). All the stuff about new valves and so on do not apply to the fixed tanks in Motorhomes as the original poster of this thread has.

This does not mean that they never need replacement, only that inspection, recertification or other items are not mandated by law here in the states. Real bad rust is a possible reason to replace the tank. Also, newer motorhome tanks have automatic fill shut off valves (like the new portable tanks have) whereas the older motorhome tanks did not. Therefor if you have an older fixed motorhome tank, you need to watch the fill process and be sure that the person filling it loosens the bleeder valve and shuts the filling off when liquid appears at that bleeder. Otherwise it is very possible to overfill the tank.

My 24' 1978 Argosy motorhome did not have an automatic overfill prevention valve. My 1983 Airstream 310 motorhome did have the automatic valve. It is still good practice to open the bleeder valve on either stile as occasionally the automatic overfill prevention valves stick and do not work as they should.

[bkahler]

Wow, lots of good information here.

Steve, I knew about the POL and the OPD from our previous motorhomes. One was a 76 model Coachmen that we had checked and serviced back in 2001. I think the installed some sort of OPD device but I'm not sure. I've slept since then!

Idroba, I suppose its good to know I don't have to have my tank inspected but I think what I will probably do is remove the tank, check to make sure it is still sound and functional and then sand blast and paint it. As you mentioned rust could be a problem and I know there are some rusty areas on the chassis and the tank obviously has some rust. I'd rather be safe than sorry when it comes to something like this.

Thanks for all the feedback!

Brad

[Keyair]

Thanks for bringing this up Brad, and thanks for the clarification guys!
It is one of the things that I was concerned about.
My tank looks fine, but does have some light surface rust here and there. I will treat it and repaint when I get to that stage!