Propane Tank Valves and Re-Certification

Dave and Helen Damouth

(revised: 6 Feb. 2002)

This is a revision of an article originally written in late 1999.  It contains general information about propane tank recertification requirements and about the requirement that new tank valves be installed before April 2002. 

The following applies to vertically mounted propane tanks with 4 to 40 pound capacity. Previous versions of this article made a distinction between DOT tanks (portable, available in both vertically and horizontally mounted versions)  and ASME tanks (permanently mounted, generally larger, and horizontally mounted only.)    Recent information makes it clear that this distinction can be ignored when considering requirements for the new OPD valve.   It is now clear that the only important distinction is that all vertically mounted tanks with capacity between 4 and 40 pounds must be refitted with OPD valves.   All tanks over 40 pounds are not subject to the new rule. 

Note added 6 Feb. 2002:  Horizontal DOT tanks of less than 40 pound capacity have recently been granted a special exemption from the OPD requirement.  See Horizontal Exemption, below.  My thanks to "Sandy McClymont"  for discovering and forwarding this new information.

About DOT tanks:

The most common portable tank is called a "DOT" tank, since it is built to conform to design and usage regulations established by the Federal Department of Transportation.   Both horizontally and vertically mounted portable DOT tanks are available, although the horizontal tank is much less common.  The horizontal and vertical tanks are not interchangeable, and must be stored, filled, and used only in the specified horizontal or vertical mounting position.

DOT tanks may only be used for 12 years after the manufacturing date. (This is according to a standard created by the National Fire Protection Association, and adopted as law by most states).  Some states may have adopted rules which specify a different period. A dealer in Minnesota claimed that the state only allow 10 years). After that, tanks must be "re-certified", giving another five years (and can be recertified repeatedly, every five years). My tanks were manufactured in December, 1987, so I needed to get them recertified or replaced by the end of 1999.  (As of January 17, 2002, a great many states have not yet adopted the new rule requiring OPD valves, and a few have adopted an early version of the OPD rule which does not exempt horizontal cylinders.  For specific state information, see the table at the end of  http://

Propane dealers are legally required to look at the date stamped on the tank before filling it. Some of them actually do look. I've now been reminded several times by dealers that my tanks were about to expire. Recertification can only be done by the large bulk propane suppliers, not by typical small dealers.  Beginning April 1, 2002, dealers in many states will also have to verify, before refilling a tank,  that vertical tanks between 4 pound and 40 pound capacity have the new OPD valve described below.

The National Fire Protection Association has recently outlawed the POL valves found on nearly all older DOT tanks. (POL is an acronym for Prest-O-Lite, the company which introduced this valve in about 1920). These valves are what almost all of us currently have - they have the familiar female left-hand-thread in the valve. Tanks with this type valve must now have the valve changed to a new type of valve during recertification, may not be sold beginning in 2000, and may not be refilled beginning April 1, 2002.

The POL valves are being replaced with a new type which uses a QCC (Quick Closing Coupling) connector. This connector has an external (male) right-hand thread on the valve. A 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 tanks without modifying the old hoses on your RV. If you like the no-tools convenience of the new style connector, or still have trouble dealing with a left-hand thread, you may also want to replace your hoses with new ones having the QCC connectors. But you can do it later - it doesn't have to be done at the same time you replace the valve.

The new valve also contains an OPD (Overfill Protection Device). So they may be called either OPD valves or QCC valves, depending on the whim of the supplier. The OPD feature makes it more difficult for the typical under-trained, uninformed, or incompetent attendant to overfill the tank. An internal float mechanism shuts off the valve when the tank is 80% filled. The 20% empty space is necessary to prevent the tank from venting large amounts of propane when the temperature rises.  This new OPD feature is not to be used as the primary overfilling control.  Rather, it is strictly a backup safety device, and filling is to be controlled primarily by weight or by the "dip tube" bleeder valve which indicates 80% fill. 

The new OPD valve also contains another important safety feature - it will not release gas unless the hose is properly connected, even with the valve open.

It is still possible to overfill the tank if the tank is not vertical or if the OPD float valve malfunctions (there have been reports of OPD devices not working properly). For this reason, it is still a good idea (and required by the new code) to monitor the weight of the tank or the number of gallons dispensed or the 80% bleed valve, not depending exclusively on the OPD device. The technician who filled my new tank monitored the weight of the tank, and verified that the OPD device shut off the propane flow just before the tank reached its specified 80% capacity.  (The old "dip tube bleed valve" still exists in the new valves.   By slightly opening a vent on the side of the valve (with a flat-blade screwdriver), one knows when the tank is 80% full because liquid propane begins spurting out this vent.)   So there are several independent ways of verifying that a tank is properly filled.  Be sure that more than one of these ways is used, particularly with a new tank, but preferably with every fill.

In the East, almost everyone who dispenses propane has a scale, and monitors weight of the old tanks during filling. This still works fine with the new tanks. In the West, many places don't have scales. With old tanks, they depend on the dip tube vent and a measure of gallons dispensed. Some of these people are lazy and now depend *only* on the OPD valve (which is not legal).  When filling an OPD tank that wasn't completely empty, this provides no useful backup indication in case the OPD device fails - somewhat unsettling. This won't affect me personally, since I always wait until a tank is empty before refilling.

The ASME tanks have been using an earlier type of OPD float for about 14 years, and are usually refilled when only partially emptied. If a significant number of float failures have occurred, I'd expect that we've have heard about it. I wonder if the float mechanism on those tanks is different and more reliable?

Replacement or Recertification: 

In October, 1999, as my recertification deadline approached, I asked around to find the best way to upgrade or replace my tanks. New 30 pound tanks cost about $50 at a large propane distributor and up to $70 at RV stores. This is for an *empty* tank.

One propane dealer quoted me a price of $35 to install a new-style valve and recertify my existing tank. This would require dropping off my tanks and picking them up at some time in the future (I'd have to get along without propane in the trailer in the meanwhile, or else make two trips there and back, leaving one tank at a time). And this price doesn't include a propane fill.

I found a much better deal, in the Finger Lakes region of New York. Ballantyne RV, in Victor, NY, had a supply of reconditioned tanks which they exchange for an old tank. I bought a reconditioned 30-pound tank, with new OPD valve, re-certified, repainted, already full of propane, for $21.39 (including 7% tax). Unfortunately, they only had one 30-pound tank in stock, and said that their supplier wouldn't be delivering more for at least 10 days. (They had plenty of 20-pound tanks).

A week later, when I emptied my other old tank, I drove to the supplier - Phelps Sungas, Inc, whose main distribution center is about 5 miles north of Geneva, N.Y. They have a huge supply of tanks, and sold me another reconditioned tank, full, for $29.09 (including tax) in exchange for my old tank. This price feels about right. I suspect the lower price at Ballantyne was either a mistake (although the price was posted on the wall) or an obsolete price. It seems too low, considering that a propane fill alone at that time was costing between $11 and $18.

Phelps has two other branch locations in the Finger Lakes, but doesn't stock 30-pound reconditioned tanks at the branches. They also probably supply other RV dealers in the area with tanks for exchange.

I don't know if this kind of exchange deal for 30-pound tanks is available elsewhere in the country, but it is certainly worth hunting for. Exchange of 20-pound tanks is quite common at lawn and garden centers, large hardware stores, and other such places all over the country, but this is the first time I'd seen it offered for 30-pound tanks. Be careful - the usual exchange place may give you a tank with an about-to-expire certification and with an old-style valve unless you specifically ask for an OPD valve and you personally search through their stock looking for a recent certification.

The new valve is easily recognizable. It has a triangular valve handle and large external threads at the hose connection. The date of manufacture (and date of recertification, if this has been done) is stamped into the metal near the top of the tank, and is a numeric month and year (1287 means December 1987).

Don't forget that you will lose any propane in your old tank when you take it in for a new valve or for exchange. Do it one tank at a time, when the tank is empty.

I've heard that Home Depot and other such places now sell a replacement OPD valve for about $11, allowing you to replace your old valve yourself.   It's worth checking this option if you are a DIY type of person - but you'll still need to pay for recertification when your tank is 12 years old.  Note that these replacement OPD valves are only for vertical tanks.  There apparently are no replacement OPD valves for horizontal tanks - hence the exception reported below.)

Why OPD?  The scuttlebutt is that safety was not the primary reason for changing to the new valve. The real reason apparently is that the backyard barbecue folks couldn't learn to deal with left-hand threads. Once the decision was made to change the connector, then throwing in the new safety features came almost for free.   (The references below seem to contradict this rumor - but it wouldn't be the first time that history has been rewritten).


The new connectors are great:  I have now replaced both tank hoses with new hoses and QCC connectors.  These new connectors are a major convenience for anyone who uses a lot of propane.  They are much easier to attach and detach and require no tools.   (When boondocking in cool spring and autumn conditions, where nighttime temperatures may be near freezing, we use about one 30-pound tank of propane per week).   RV stores have these replacement hoses available, in various lengths.  I got mine at Camping World for about $10 each.  Installation is trivial - requiring only a small wrench, and a little Teflon tape to seal the threads (available anywhere that sells plumbing supplies).

Barbecue Adapter: Do you have one of those adapters which fits between the propane tank and the connector hose, which has a quick-connect fitting for a hose to your barbecue grill?   The old ones won't work with the new QCC hose!  New adapters with QCC fittings weren't yet available in the stores in October 1999 (they are available now).   But my adapter had always been a problem anyway - it was so long that it was difficult to get the plastic tank cover down over the hoses with the adapter in place, and the cover forced the tank hose into a very sharp bend - a longevity concern. 

The solution turned out to be simple.  I removed the old POL valve adapters from each end of the Quick-connect fitting, and bought new adapters which allowed me to screw the quick-connect fitting directly into the pressure regulator, and then screw the new QCC hose (the end that was intended to go into the regulator)  directly into the input to the quick-connect tap.  If you can't find the right adapters, it's easy to cut the existing fitting off the end of the QCC hose and insert a new fitting (hose barb on one end, fastened with a tiny stainless steel hose clamp, and a 1/8" or 1/4" National Pipe Thread on the end that goes into the regulator.  Works fine, and is a whole lot more compact, neater, and more elegant, than the old arrangement.  Total cost for the conversion was a couple of bucks for adapters at a local hardware store.

Recent Exclusion of horizontal DOT tanks: Owners of older RV's  that use horizontal rather than vertical propane cylinders should read the following information:

The new OPD (Overfilling Prevention Device) valves will be required on 4 lb. to 40 lb. propane cylinders from 1 April 2002. However, the currently available new valves are designed only for vertical cylinders and cannot be used with  horizontal cylinders. Therefore, horizontal cylinders manufactured prior to 1 October 1998 have been exempted from having OPD valves, provided they are so labeled.  (Such cylinders manufactured after 1 October 1998 do already have OPD valves).

This information is on the website of the National Propane Gas Association. See OPD's: Information for Consumers - Questions & Answers..

Since propane dealers do not seem always well-informed, it is suggested that RV owners with pre-1998 horizontal DOT tanks should print this article and carry it with them, in case a dealer  balks at filling a cylinder without an OPD valve.

The relevant part of the document is on the second page:

Q:   I have a horizontal cylinder on my recreational vehicle. Are OPD's available for that kind of service? 

A:   The 2001 edition of NFPA [National Fire Protection Association] 58 (the LP-Gas Code) recognizes that horizontally oriented cylinders that were manufactured prior to October 1, 1998, are unable to be retrofitted with the OPD's.   As a result of this fact, the Code now exempts these cylinders from having to be retrofit with OPD valves. Any such cylinder must have a label affixed to it to inform the user and the refiller that an OPD valve is not installed."

For more information on this general subject, see the following documents from the National Propane Gas Association: This site also has a convenient search function which will allow to easily find specific topics.

(All of the following documents are in PDF format, and are opened using Adobe Acrobat Reader.)

Top       RV Info Menu       Home