REFLECTOR: Fuel venting issue

[Douglas Holub]

"I also connected a ground wire from this vent line and it connects to the 
filler cap. These vent lines are grounded through a 100 Kohm resistor to 
ship ground. This reduces the amount of spark that would be generated if 
there was a static charge difference between the fuel hose and the filler 
caps."
-------------------------------------------------------------------------
That doesn't sound right to me. If the airplane collected a static charge in 
flight, I would expect the entire airplane, including the electrical system, 
to have thousands of volts compared to the fuel hose. The ship's electrical 
system ground is unrelated to earth ground.

Doug Holub

----- Original Message ----- 
From: "Ron Brown" <romott at roadrunner.com>
To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
Sent: Sunday, July 01, 2007 4:25 PM
Subject: Re: REFLECTOR: Fuel venting issue


>
> I have had excellent fuel flows and venting on my 173.
>
> I used 3/8" lines from the mains and the header tanks lines up to a couple
> of tees up high on the firewall.  Then there is a 3/8 line that runs all 
> the
> way to the top of the fuselage then back down the firewall and out the
> bottom.  I also installed the factory recommended check valve in the left
> vent line coming from the tank.  I have never smelled fuel in the cabin.
>
> My tanks stay equal on long flights - but this is very dependent on having
> fuel caps sealing well.  I put Vaseline or white lithium grease on the 
> fuel
> cap O rings about every six months.  I did run my vent lines into the tank
> at the very top and made a run toward the filler cap.  I drilled several
> holes in this line inside the tank.  I also connected a ground wire from
> this vent line and it connects to the filler cap.  These vent lines are
> grounded through a 100 Kohm resistor to ship ground.  This reduces the
> amount of spark that would be generated if there was a static charge
> difference between the fuel hose and the filler caps.
>
> Ronnie
>
>
>
> ----- Original Message ----- 
> From: "David Staten" <Dastaten at earthlink.net>
> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
> Sent: Sunday, July 01, 2007 3:51 PM
> Subject: Re: REFLECTOR: Fuel venting issue
>
>
>>I will have to take another look at the plans, I dont recall us having
>> our check valve set up in that manner.
>> Thanks for the feedback.
>>
>> Dave
>>
>> Alex Balic wrote:
>>
>>>The check valve is located inside the plane and above the level of the
>>>fuel
>>>in the tanks (right up at the roof- it T's into the vent system, so fi 
>>>the
>>>external vent fails, it will open and allow air into the tanks from the
>>>cabin- but not let fuel/fumes out into the cabin.
>>>
>>>-----Original Message-----
>>>From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
>>>Behalf Of David Staten
>>>Sent: Sunday, July 01, 2007 12:49 PM
>>>To: Velocity Aircraft Owners and Builders list
>>>Subject: Re: REFLECTOR: Fuel venting issue
>>>
>>>If the check valve is on the same line that is theoretically blocked by
>>>ice or mud, how is it able to prevent ANYTHING? An obstructed vent is an
>>>obstructed vent.
>>>
>>>Dave
>>>
>>>Brett Ferrell wrote:
>>>
>>>
>>>
>>>>The check valve is actually there to prevent tank collapse should the
>>>>vent line become blocked (by say a mud-dauber or ice accumulation).
>>>>I've seen a 15,000 gallon steel tank collapse by a plugged vent, and
>>>>it's not pretty...
>>>>
>>>>B
>>>>
>>>>Scott Derrick wrote:
>>>>
>>>>
>>>>
>>>>>Hmmm...
>>>>>
>>>>>{snip}
>>>>>
>>>>>Just recently  I noticed a one way valve had been added to the single
>>>>>line running out of the block to prevent flow out of the vent line and
>>>>>thus only allow air to flow in.   I don't have this one way valve and
>>>>>wondered why I would need it?  I guess this scenario answers my
>>>>>question.
>>>>>
>>>>>{snip}
>>>>>
>>>>>Scott
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>------------------------------------------------------------------------
>>>>
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>>>>
>>>
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>>
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>
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