Date: Wed, 14 Oct 2015 23:56:54 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: propane tank going bad
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To be honest I don’t know and I haven’t found a definitive answer. While some states have laws and processes in place for the testing of ASME rated pressure vessels those used for single dwellings or having heating capacities under 200,000 btu’s or under 100 gallons seem to be exempted from required inspections.
Look at things this way. Propane is only liquefied due to being under pressure. Get a pin hole or other breach and it is coming out. Not dripping, but an atomized spray looking like it is being delivered by a fuel injector. Propane has an extremely wide flammability range, (air to fuel ratio). Gasoline is fussy in comparison. Gasoline avoids burning in both an oxygen deficient or oxygen rich environment. See that propane cloud? Add any ignition source and it is going up and fast. Sort of like dropping a wrench across a battery and having it weld in place. Nothing you can do until the fuel is exhausted.
Now while a I wouldn’t condemn a tank with surface rust once it is pitted and it is obvious that material is missing time for it to be retired. Not only is the missing material of concern but with those pits there could be stress risers and stuff that could actually cause the tank to tear under some conditions. Keep in mind that not only is the tank designed to holds normal storage pressure and temperature conditions but also be able to put up a fight in the event of a collision. Also, if involved in a fire, the relief will vent at a controlled rate so the tank ahs to maintain integrity during that pressure and temperature condition so as not be a shrapnel bomb.
So if the tank is damaged enough to need grinding, cleaning, patching, etc., it is time to replace it. Putting a lot of effort into reusing a defective tank will only help to prove negligence when something goes wrong.
I also suggest those considerations for those looking to add capacity, dual used tanks, incorrect plumbing methods etc. That small tank was used in part to the small space of the vehicle. When my tank failed it took about an hour for that one gallon to vent out. Luckily that filling station was far away from a highway and the truck stop building.
Dennis
Sent from Mail for Windows 10
From: mcneely4@cox.net
Sent: Tuesday, October 13, 2015 9:53 PM
To: vanagon@GERRY.VANAGON.COM;Dennis Haynes
Subject: Re: propane tank going bad
OK Dennis, at what point do we just decide our tanks are too old and must be replaced for safety? My 1991 Volkswagen Vanagon GL Campmobile has the original tank and plumbing. It has live in Idaho, Arizona, Kentucky, Oklahoma, and now Washington. The Chassis has 179+K miles. I've experienced no problems. The rock shield is rusty.
David McNeely
