Diesel Fuel is migrating between tanks

[CarlF]

MV,

The "drawing equally from both tanks" just doesn't sound right. I've never seen a boat with two tanks set up this way.

In your other post "Willard Rewire Project Done" the "before" picture shows the lower supply valve off and the return valve handle to the right. I would guess that is the correct setting for one of your tanks. Of course, you should confirm by watching the gauges. I would then post a large diagram that shows the correct handle positions for each tank.

Carl

[SkiprJohn]

Aloha MV,
When I got my engine running correctly I was truly amazed at how fast the return line can pump up a tank. So taking from one tank and returning it to another will make the tank returned to fill quite quickly with no apparent reason. I don't know how I'm going to sort it out but first is to know which tank lines go where and in what position the handle needs to be to feed the engine from each tank. Certainly is much simpler to have one tank, eh?
Kind regards,
JohnL

[SV Someday Came]

Originally Posted by SkiprJohn

Certainly is much simpler to have one tank, eh?
Kind regards,
JohnL

Yeah, you could say that. Carl is right -- the old "before" photograph does show one valve in a different position. I am not sure when that one was changed.

I'll sort it out eventually.

Next time I am buying a new boat with a warranty and manuals.

Kidding.

Michael

[GordMay]

Originally Posted by SkiprJohn

... I don't know how I'm going to sort it out but first is to know which tank lines go where and in what position the handle needs to be to feed the engine from each tank. Certainly is much simpler to have one tank, eh? ...

Originally Posted by MV

... Next time I am buying a new boat with a warranty and manuals ...

Originally Posted by CarlF

... Of course, you should confirm by watching the gauges. I would then post a large diagram that shows the correct handle positions for each tank ...

All of which explains the ABYC requirement* that:

H-33.14.7 In systems with multiple engines and/or multiple tanks, valves at junctions shall be labeled as to function and position.

H-33.17.7.1 There shall be a label, or diagram, or other marking, near each valve to indicate it’s function and position.

Followed by the
NOTE: When fuel is not being returned to supply tank there may be a potential for overflow.

* Standard H-33 Diesel Fuel Systems

[Chief Engineer]

I think they got the message before

Originally Posted by GordMay

All of which explains the ABYC requirement* that:

H-33.14.7 In systems with multiple engines and/or multiple tanks, valves at junctions shall be labeled as to function and position.

H-33.17.7.1 There shall be a label, or diagram, or other marking, near each valve to indicate it’s function and position.

Followed by the
NOTE: When fuel is not being returned to supply tank there may be a potential for overflow.

* Standard H-33 Diesel Fuel Systems

[GordMay]

Some things are more obvious than are other things, just as some things are obvious to some people, yet not to others.

[SkiprJohn]

This is bad on my part but I too often forget to label and draw diagrams when I get something working right because it now works and I want to use it not sit around and draw stuff. That's why the obvious reminder. Its obvious when you want to go back and figure something out but not obvious when you skip the step.
Those are good regulations and make things better for all.
As far as buying a new boat with an intruction manual - usually they have similar problems.
JohnL

[GordMay]

Originally Posted by SkiprJohn

This is bad on my part but I too often forget to label and draw diagrams when I get something working right because it now works and I want to use it not sit around and draw stuff ...

I have over 40 years experience as an electrician, designer, and project manager, yet I ALWAYS* draw a circuit (at least schematically) BEFORE I wire it.

* Excepting the very most elemental circuits./

[Chief Engineer]

"we" put it together "we know" how it works.

Originally Posted by SkiprJohn

This is bad on my part but I too often forget to label and draw diagrams when I get something working right because it now works and I want to use it not sit around and draw stuff. That's why the obvious reminder. Its obvious when you want to go back and figure something out but not obvious when you skip the step.
Those are good regulations and make things better for all.
As far as buying a new boat with an intruction manual - usually they have similar problems.
JohnL