Rethinking the fuel tank situation

Discussion in 'Boat Design' started by the brain, Oct 26, 2016.

  1. the brain
    Joined: Sep 2016
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    the brain Senior Member

    today I fixed unclogged rather the fuel pickup tube in the primary tank also electricalley connected the Bosh fuel guage connected sender+12/-12 and It read 1/4 tank (I have about 4 gallons in a 15Gallon tank.

    I find a clogged screen/fliter on PU tube the other PU tube had a stuck check valve so I persuaded the little ball to unstick w/ a hammer/punch I'm concidering knocking that ball out like it's there for a reason right?

    should check ball be removed?

    haven't
     
  2. Barry
    Joined: Mar 2002
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    Barry Senior Member

    The ball might be an anti siphon check valve controlled by a very light spring.

    When the fuel pump pulls a little suction, the ball opens and lets fuel flow to the pump. When the suction stops, the ball closes the fuel line.
    The idea is that if you have a fire and the hose is cut/burned through below the height of the fuel in the tank, then the fuel will not siphon and continue to feed the fire

    These anti siphon check valve can plug up with crud and not provide the anti siphon function OR just plug up the line

    They must be clean
     
  3. the brain
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    the brain Senior Member

    OK sounds good hows the easy way to keep the ball clean.

    I also routed the vent tube on the mollier tank(in the corner) out though the splashwell I'll fab a bracket to hold the vent opening.

    how doe's this sound the vent sticking out the SW. I was going to reuse the orginale tanks opening in the side however I had I hard time finding 1/2 ID fuel line.
     
  4. Barry
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    Barry Senior Member

    If the vent emptied into the splashwell, it would be pretty close to the engine. Not very safe
     
  5. the brain
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    the brain Senior Member

    any suggestions on extending the 1/2" fuel line vent tube like can I use automobile fuel line for the vent?

    or a place to buy.
     
  6. the brain
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    the brain Senior Member

    can I connect a OMC fuel line directly to the water /fuel separater (it has two ins and two outs) this for my reserve 6 gallon just incase tank?

    like can I connect 2 ins and one out of my water /fuel separater?
    Thanks TB
     
  7. Ike
    Joined: Apr 2006
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    Ike Senior Member

    Do not use automotive fuel hose. It does not meet marine fuel hose standards. Use only hose marked USCG Type A (or B for vent hose) Type A passes a fire test. B does not have to pass the fire test. But since vent hose normally does not have fuel in it, it doesn't need to. Plus that marine hose is resistant to alcohol and other additives in the fuel, and meets EPA requirements for evaporative emissions.

    Barry: yes you can be sued, even if you meet all ABYC standards, but it helps as a defense, but not absolutely. However, the injured party's attorney will make a point of stressing it if you don't, and most juries are very sympathetic to injured parties when the boat didn't meet safety standards.

    Yes the Canadian standards were derived directly from ABYC. They are online, free at http://www.tc.gc.ca/eng/marinesafety/tp-tp1332-menu-521.htm
     
  8. the brain
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    the brain Senior Member

    thanks for explaining the A/B type fuel lines. and I won't use auto fuel line,

    how doe's this look
    http://www.ebay.com/itm/321203699160?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

    still curious about connecting my reserve tank?
    can I connect a OMC fuel line directly to the water /fuel separater (it has two ins and two outs) this for my reserve 6 gallon just incase tank?

    like can I connect 2 ins and one out of my water /fuel separater?
    Thanks TB
     
  9. Ike
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    Ike Senior Member

    Yes that's the right stuff. MPI is out of Ohio http://www.marinehose.com/
    They have been around since the 80's. There is also Shields and Trident and others. Beware of chinese hose. There has been a lot of it on the market that does not meet US standards even though it is marked USCG Type A and ISO 7840
     
  10. Barry
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    Barry Senior Member

    Only if you put a shut off valve on each inlet
     
  11. the brain
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    the brain Senior Member

    you say this because it would be hard to build preasure w/ another empty tank connected to the water separater?

    remember I have the 3 way fuel valve so I'm able to open and close either primary or secondary tanks w/ the 3 way valve.

    Thanks STB
     
  12. Barry
    Joined: Mar 2002
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    Barry Senior Member

    No, because you do not want to draw into the filter with both inlet ports open to two tanks, the tank with the least resistance to the draw will empty first. The resistance to draw can vary with the length of hose, restrictions if you have an anti siphon valve and the height of the fuel in either tank
    Therefore as if you only have one tank open to the filter, the other tank closed to the 2nd inlet on the filter, there will not be a problem

    Yes you only need to use one outlet to the tank
     

  13. the brain
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    the brain Senior Member

    ok good I'll close both pri/sec tanks when using 6 gallon reserve.

    thanks tb
     
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