Where to get an RV propane cylinder requalified (and when you need to)

When an RV propane cylinder is due

The portable cylinders on travel trailers and fifth wheels are DOT specification cylinders, usually DOT 4BA or 4BW. Federal rules in 49 CFR 180.209 give a coated cylinder in LP service 12 years from its manufacture date. After that it has to be requalified by a business holding a PHMSA approval before it can be refilled. The method chosen sets the next deadline.

Where the requalifiers are

Florida, Texas and California sit near the top, as their size would suggest, but the order is not a population ranking. Florida's total is lifted by 344 sites approved for pressure testing, far more than any other state. Michigan has more sites than California, and rural states such as Montana (74), North Dakota (60) and Wyoming (46) have more than their population alone would suggest.

For most RV owners the visual inspection is the one that matters: it is permitted for LP cylinders, it is the most widely available, and it is the method behind the E stamps common on requalified tanks. A cylinder with rust pitting, dents or a damaged foot ring may be rejected at the visual and must then be pressure-tested, repaired or condemned, which is why the smaller pool of pressure-test sites matters too.

How to read the stamp on your cylinder

• Find the collar. The manufacture date is stamped into the ring around the valve as month and year. Blue Rhino notes the requalification date is usually on the edge of the collar.
• Look for a later stamp. A requalification mark has the month on the left, the requalifier's four-character RIN set in a square, and the year on the right. In the example in 49 CFR 180.213, a cylinder requalified in September 2006 by RIN A123 shows 9, then A1 over 32, then 06.
• Read the letter. E means a 5-year visual inspection, S means a 10-year proof pressure test, and no letter means a 12-year volumetric expansion test. A visual-only requalifier may stamp its visual inspection number (for example V123456) instead of a RIN.
• Add the interval to the newest date. That is the month after which the cylinder cannot be refilled.
• Check the requalifier. You can look up any RIN or V-number in the PHMSA locator.

Exchange is an alternative

Cylinder exchange programs swap an empty tank for a filled one, and the exchange company takes on requalification. Blue Rhino says it requalifies tanks as part of its process. AmeriGas says a tank from its exchange program has already been recertified. Both programs are built around the standard grill-size tank; Blue Rhino accepts "any standard empty grill tank." Owners of 30- or 40-lb RV cylinders should plan on requalifying their own.

What it means for you

• Read both collars now. If the newest date plus its interval falls this season, get it done before a trip, not at a fill station that turns you away.
• Search the PHMSA locator by city or ZIP. It lists each site's approval type and the cylinder specifications it covers. Call ahead to ask whether the site requalifies 4BA or 4BW cylinders for the public and what it charges.
• Expect a rusty cylinder to fail. Pitting, dents and a bent foot ring can get a cylinder rejected at the visual inspection. Price a new cylinder before paying for a pressure test on a bad one.
• Buying a used trailer? Expired cylinders are easy to miss on a rig that has been sitting. A pre-purchase RV inspection or a dedicated RV propane inspection records the dates and leak-tests the system. Mobile RV inspectors can do it where the rig is parked.
• Motorhome owners: a mounted ASME tank is not on this schedule. Our RV expiration dates chart covers it and the other dates hidden on a rig, and our state rules guide covers state inspection requirements.