Attach regular 20# LP tanks lying down

08-11-2010, 10:06 AM

I have a 2005 3124KS and the front end is made for two LP tanks that come from TM made with ways to connect to the frame up front. I do not have those tanks, but I do have two standard, round, 20# tanks.

Any suggestions on how to attach them to the frame up front? (Just so you know, it does clear when opening the front half.)

mcgyver210 · 08-11-2010, 10:24 AM

I actually don't have a slide version but have read quite a bit about them here & I don't believe you can use standard tanks on TMs with slide fronts due to the difference in tank & valve design. Standard tanks are not designed to be used on their side.

I could be wrong & if so I am sure someone that actually uses this style tank will correct me.

ZekenSpider · 08-11-2010, 10:39 AM

The horizontal tanks supplied by TM (made by Manchester Tank) are made specifically for horizontal mounting. They have a special internal construction to prevent liquid propane from entering the system.

Mounting standard vertical propane tanks in a horizontal position would be very dangerous as it would allow liquid propane into a system designed for gaseous propane use only.

Get more information at <www.manchestertank.com>.

Jerry

mcgyver210 · 08-11-2010, 10:45 AM

Jerry you did a better job of explaining than me the only thing missing was the pic of the explosion to come

**ShrimpBurrito** · 08-11-2010, 11:04 AM

Jerry is right. DO NOT use standard vertical tanks in a horizontal position. There is both liquid and vapor components to compressed propane; the liquid settles to the bottom & the gas it at the top. You want to burn vapor....if you end up burning any liquid, things will get very unpleasant very fast.

There are 2 specific problems doing what you suggest:

1) Oriented in the vertical position, horizontal LP tanks have their valve at the top, but off to the side. The side with the valve is opposite the mounting brackets, such that when the tank is horizontal, the valve is still at the top of the tank. This is important because, as above, liquid is at the bottom and vapor is at the top. In contrast, if you use a regular BBQ vertical tank in the horizontal position, the valve will not be at the top -- it will be in the middle. Thus, the valve is in the middle of the the liquid phase, and when you open the valve, and the tank is say more than half full, liquid propane will come out. Very bad.

2) If the first problem were not bad enough, there is an additional safety issue. And this safety issue also applies to those folks who have properly installed vertical tanks that transport them in a horizontal position for refilling. Bottom line: it's not a good idea. All propane tanks have a safety relief valve built in to the OPD valve. This valve opens to prevent the tank from exploding if too much pressure builds up in the tank. The problem lies again with liquid propane escaping instead of vapor. Since the relief valve is adjacent to the service valve, liquid propane will be next to the valve. Thus, if the relief valve does open, liquid propane will be vented. Since liquid propane is compressed vapor, and liquid propane is ~240x as dense as vapor (see http://encyclopedia.airliquide.com/E...a.asp?GasID=53), 240 times as much liquid propane will be vented within any given time vs. vapor propane. You'll have a much greater chance of fire, and a bigger one at that.

You need to buy horizontal tanks. Obviously, there is not nearly the demand for them as vertical tanks, so they are hard to find. Check online and at large propane suppliers (like Amerigas). Be sure to have your wallet ready -- expect to pay $150-$200 for EACH tank.

Dave

Wavery · 08-11-2010, 03:35 PM

http://www.instawares.com/horizontal...=17-60289551-2

http://cgi.ebay.com/ws/eBayISAPI.dll...m=260639364200

**ShrimpBurrito** · 08-11-2010, 03:38 PM

Quote:

Originally Posted by harveyrv

http://www.instawares.com/horizontal...=17-60289551-2

Note that this tank is a 30 pounder, and will not fit on the TM tongue.

The one Wayne linked to on eBay though is the one you want.

Dave

08-11-2010, 04:53 PM

I am always interested in issues that might cause the TM to become part of the sky. Is the reverse also true, ie. you shouldn't use/transport the horizontal tank in a vertical position? This would include using a horizontal tank with the family barbecue in the back yard, unless it was on it's side???

**ShrimpBurrito** · 08-11-2010, 06:19 PM

Quote:

Originally Posted by Scott O

you shouldn't use/transport the horizontal tank in a vertical position? This would include using a horizontal tank with the family barbecue in the back yard, unless it was on it's side???

If you call Manchester as I did awhile back, they will tell you "NO", you cannot use a horizontal tank in a vertical position. However, the rep I spoke with couldn't give me a reason why other than "because it wasn't designed for that", so it's possible that was just a stock answer with no particular reason. I personally cannot think of a reason why doing that would be an issue, but since I really have no reason to do that, I haven't explored the issue further.

On a related note, the reason why the horizontal tanks must be removed and filled in a vertical position has to do with the OPD valve. The valve consists basically of a plastic slotted tube with a ~1/2" diameter float that rides inside. On the horizontal tanks at least, and presumably the vertical tanks as well, the tube is in a vertical orientation when the tank is also in the vertical position. It looks like this:

When the propane level reaches the float, the float rises and eventually will close off the valve. If you fill the tank in the horizontal position, the float and tube are also in a horizontal orientation, and thus, the float cannot rise to close off the valve. In such a scenario, you can potentially fill the tank beyond the recommended level. It then could potentially explode if the tank pressure rises and the relief valve fails. It's a secondary safety device -- the relief valve is no end-all safety measure, even if it operates as designed. If it opens when the tank is in your steaming hot trunk, the end result will be the same as if it never opened.

Dave

08-12-2010, 12:47 PM

Wow! Thank you all for the through and quick responses. If I thought if through about the liquid issue, I would have figured that out. I will purchase the correct tanks or transport the standard vertical tanks upright and hook up after I set up with them in the proper position.

Thank you all for your help.