Atwood 8803LP2 Tank for Fuel Pump Conversions

[drifter]

I have done several conversions from twin line pressure systems to a Briggs fuel pumps. I have started using the Atwood 8803LP2 plastic tanks because they are not expensive and the 3 gallon size is perfect for my smaller OMC outboards.
These tanks are the “new” EPA mandated ventless tanks (auto vent for vacuum). The downside is they can build up significant pressure while in use. The claim from Atwood is that the tanks will withstand up to 20PSI.
So far, I have not had any issues in running them (much of the use has been in test tank situations). However, here in Texas we are experiencing record heat.
I wonder if the pressure gets high enough that it might overwhelm the float valve. I know the old twin line pressure tanks have a relief valve (5 psi)?
So, my question is: has anyone using these tanks on our older motors experienced any problems? I know I could just leave the cap loose, or replace the cap with a vent screw cap, but I’m not sure I need to or want to.
Thanks

[billw]

At least with Mercury’s EPA tanks, they use something called a demand valve. It’s actually made by Attwood, too. It goes inline between the tank and the primer bulb. The idea of it is that it will withstand high fuel tank pressure but not open until the fuel pump on the engine creates a negative pressure in the fuel line. These are especially important when you tip the motor up and the float valve may not be as effective in shutting off the fuel.

https://www.ebay.com/itm/273375882259?epid=1218878583&hash=item3fa678ec13:g:52IAAOSwD9pbWzZ-

Long live American manufacturing!

• This reply was modified 2 years, 9 months ago by billw.

[billw]

Just my opinion but the new fuel tank is a typical EPA device, made to make things more green but usually ends up making things more dangerous and sometimes, even more messy with the fuel than it would have been without the EPA’s help.

Long live American manufacturing!

[drifter]

Been thinking about this EPA compliant “solution” to keeping gasoline vapors out of the environment.
Attached is a photo of the manufacturers label affixed to the tank. Interesting…….
Also, embossed into the tank body in the following warning “CAUTION: Release Tank Pressure Prior to Connecting or Removing Fuel Fittings from the Tank, Fuel Lines or Engine”. This warning is easily overlooked as the embossment is shallow and the same color as the tank.
A couple things come to mind: This tank can and does build up pressure. It builds enough pressure that fuel lines, primer bulbs, and fittings could burst if they were at all weak. I can just envision disconnecting a fuel fitting and having fuel spray about, or having a line or primer bulb burst with the same result. What about removing the motor and laying it down with the fuel line still connected. The float may let fuel easily by pass the needle (in this position) and dump fuel out into boat of floor. Some research on this tank states that it is tested to 20 P.S.I.
But, I think the thing that mystifies me the most is following the manufacturers directions to release the pressure (as stated in the caution message ). Won’t that release vapors in to the air? So, what was solved? What was made more dangerous?
My advice would be to steer clear of the “auto vent” tanks.

[drifter]

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