Dual tanks with electric pump and manual valves

[e30bradley]

What is the best way to use dual tanks independent of each other with electric pumps? Should I wire in another fuel pump next to my rear tank with a filter before it just like I did the front tank and then put the valves on the floor pan next to the seat?

I installed a 40 gallon isuzu tank into the rear of my frame and would like to start using it soon. any suggestions? I don't trust the electric selector valves because one caused me to break down and get towed home 40 miles and miss many hours of snow plowing work I was in the middle of doing.

 

[IDIoit]

2 ball valves, 1 for the feed, 1 for the return.
i would only use 1 electric pump. unless you want to install one as a back up.

 

[fsmyth]

One 4-way ball valve:
https://0c074d522cc96a09f3a6-cd6844ebeaebf35ce76089ee04af4af7.ssl.cf2.rackcdn.com/OM_MPF150_2012.pdf

 

[e30bradley]

If I where to use one pump it would have to be all the way near the front cab mount so that it is after the valves. Would the pump pull fuel up 18" vertically and then through 10ft of hose and through my 100 micron hydraulic filter and the ball valve? I am currently using only the front tank like so:

Sending unit has a hose to a 100 micron stainless mesh hydraulic filter, then about 8" of hose to a Facet pump then to the engine.. All between the front of the front tank and the trans crossmember.

 

[TahoeTom]

http://www.oilburners.net/forums/sh...tor-Valves-Electric-AND-Mechanical-fuel-pumps
Here is a write up from the tech articles.

 

[IDIoit]

gotta get a puller pump, like a faucet

 

[crash-harris]

^^^ what he said. The Duralift pumps are used to pull diesel about 30' or so. If I ever do mechanical valves, I'll leave all the wiring for the fuel level curcuits connected to the switch on the dash and just flip it after turning the valves.

 

[e30bradley]

I have a facet pump installed right now, just in front of the front tank with a 100 micron hydraulic filter before it. If I read that article correctly, the fuel gets pulled all the way from BOTH tanks through the valves and then gos to the electric pump?

 

[e30bradley]

I made a sending unit for my rear tank, it has 18" of vertical 3/8" fuel line. I am really just wondering if my facet pump will pull fuel through all that hose from the back tank, up the the floor pan, through ball valves, and all the way back down to the frame rail by the transfer case.

 

[crash-harris]

Reloacte the pump forward.

With mechanical valves, if you use 2 (simpler to understand, but a 4 way, 2 ports open at once is the same principle), fuel pulls from one tank (valve 1) and returns to the same tank (valve 2, turn both valves to same tank). When you want to switch tanks, turn both valves so it will pull and return fuel to the same tank instead of pulling from one/returning to another.

 

[mblaney]

Ummm, wouldn't you need two three-way valves? I would think that having two three ways would be the easiest way to switch feed (one valve) and return (second valve). Valves like the pic could be mounted back to back such that the handles are together (shrink wrap them together) as one handle.

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I would think that would be easiest and pretty simple to figure out plumbing-wise. Now if you used two - three way solenoid valves you would be back where you started

 

[crash-harris]

That would be the valves you need for running 2 seperate valves for feed (valve 1) and return (valve 2).

 

[fsmyth]

Yup. Two 3-way or one 4-way.
And most pumps will handle a long pull, AS LONG AS THE LINES/FILTERS ARE FULL.
Only gear pumps will consistently pull a vacuum. Most vane pumps will pull a limited
amount (say, just a bit of air in the lines). The Duralift seems to work well, according
to consensus. Dunno it's construction, never had one.
The centrifugal types are only good as a booster pump, following a real one.
They will never prime alone.

Install your pump where it is convenient, BEFORE the filter(s).
Use strainers in the tank, if possible. The small in-line (150-micron) filters are
good insurance - keeps crap out of your pump.

One of the nice things about trucks with 2 saddle tanks - both at same level, and
plumbed in parallell. Only one return line to either tank

 

[mblaney]

Yup. Two 3-way or one 4-way.

One of the nice things about trucks with 2 saddle tanks - both at same level, and
plumbed in parallell. Only one return line to either tank

Ok, I see how you are using one 4-way if the tanks are plumbed together. If they are plumbed together (essentially one bigger tank) then why have a valve at all?

 

[fsmyth]

No. The 4-way is for separate feed/returns (split tanks). Only necessary if the tank
levels differ. Same as two 3-way valves tied together, with less plumbing.

Saddle tanks generally don't have a valve (exc. a drain on tank bottom, sometimes).