fuel selection valve arrangement 2 tanks 3 engines

Discussion in 'Propulsion' started by sdowney717, Aug 16, 2012.

  1. sdowney717
    Joined: Nov 2010
    Posts: 1,175
    Likes: 84, Points: 58, Legacy Rep: 274
    Location: Newport News VA

    sdowney717 Senior Member

    Currently I have both tanks coming into a central fuel manifold with three selector valves.
    Boat has gas engines so no fuel returned. In future might get diesels who knows.

    Basically off-on valve for a tank then a tee to feed an engine filter then crossflow tank to tank valve then a tee to feed other engine filter then tank off-on valve.

    Hey it works. The third engine a gen, just tees off one of the tees and has a filter close to it.

    But was thinking of what happens if a filter clogs? Then the engine that uses that filter wont run.

    So If the filters came before the selector valves then both engine could use one filter. And if a filter clogged, I could use the other tank.
    That also means gen would have to draw thru 2 filters, so get rid of that filter. Or leave it in the circuit.

    Any thoughts on this?
    When I select both engine to run off one tank, could 2 main engines draw fuel from one 3/8 line and filter instead of just one 3/8 line?
  2. WestVanHan
    Joined: Aug 2009
    Posts: 1,374
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    Location: Vancouver

    WestVanHan Not a Senior Member

    I'm a bit confused by your description- I'm a visually based person.

    What I do is: run a Y or T junction- after each one is a valve,then a filter,then another valve and they link back together via another Y or T.

    Run one filter,other is off,can change filters on the fly if need be by turning the valves to seperate the dirty filter from the circuit.
    You can run back up lines and taps and such-and I'd recommend being more attentive to your fuel and tanks.

    I polish my fuel all the time so it's quite redundant.
  3. tunnels

    tunnels Previous Member

    Two motors off a 3/8 line ok at slow speed but once speed increases the motor with the stronger pump will starve the other so you could end up with one motor doing a starve and low on power or even stop completely .
    Two tanks two pipe systems two filters both motors should be able to feed off either tank of both off any tank . the third smaller motor should come off its own line off any tank . Big pipes hardly even block unless its something major! really major . in which case i should be able to be isolated and the other motors bypass it and carry on . Is there a Fine filter on the pick up end of the pipe in the tank as well ??. Manifolds need a filter before !! you sure as hell dont need gunk getting that far !!.


  4. sdowney717
    Joined: Nov 2010
    Posts: 1,175
    Likes: 84, Points: 58, Legacy Rep: 274
    Location: Newport News VA

    sdowney717 Senior Member

    Dont think so. These are monel tanks 145 gallon Seafair name.

    Typically I use one tank. Other tank fuel is ancient and i use in the generator.

    fuel flow picture
    If I put the filters before the cross feed changeover valves, why not?

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