Twin Fuel Tanks - 4 Way Valve Installation

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kezguy
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Twin Fuel Tanks - 4 Way Valve Installation

Postby kezguy » Mon Sep 03, 2018 11:32 am

Hi All,
I purchased a MOELLER 4 Way Fuel Valve to plumb two 50 gallon tanks Port & Starboard. Each tank has a SINGLE PICKUP.

The valve has 4 positions - turning clockwise they are OFF, STBD ONLY, BOTH, PORT ONLY. It has three inlets STBD, BOTH, PORT and one outlet to filters from the bottom.

How to plumb the valve? No schematic came with valve and I can not anything on line. SEE MY ATTACHED SCHEMATIC:

My goal is to always draw from both tanks with ability to shut off A or B if desired. This could be easily done with two separate shut offs before e T-Connection.

Am thinking the 4 way valve requires two pick ups on tank ?
What am I missing?

Thank
Karl

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billy c
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Re: Twin Fuel Tanks - 4 Way Valve Installation

Postby billy c » Mon Sep 03, 2018 2:26 pm

From their site:
Provides for withdrawal from one tank at a time only. Connects 3 permanent tanks to a single motor.
(insert Witty phrase here)
Billy's Belle Isle website

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Milhouse
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Re: Twin Fuel Tanks - 4 Way Valve Installation

Postby Milhouse » Mon Sep 03, 2018 2:43 pm

kezguy wrote:I purchased a MOELLER 4 Way Fuel Valve


Please provide a link so we can see what one you got.

I have a Groco and it has 4 ports. It connects three ports at any single time and if you plumb it as is have shown then you get the functionality that you desire.

If yours does not do this then I recommend getting the one I linked above.

Picture Below
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valve.jpg
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Jim
16' Ski Boat Restoration
17' Overnighter Sloop

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Bill Edmundson
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Re: Twin Fuel Tanks - 4 Way Valve Installation

Postby Bill Edmundson » Mon Sep 03, 2018 3:44 pm

I have the valve shown in Jim's post. It is one tank at a time. After I thought about it, that is what I want. I can balance the tanks. Current USCG rules make it difficult to make gravity transfer between tanks. Aside from a possible safety issue, would you want to transfer bad fuel from one tank to the other? My plan is to run one tank down, then go to tank 2. Fill tank 1 for later. That way you keep fresher fuel. Don't run each tank "dry". If you have bad fuel, then you can go back to the other tank.

Bill
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Milhouse
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Re: Twin Fuel Tanks - 4 Way Valve Installation

Postby Milhouse » Mon Sep 03, 2018 7:23 pm

Bill Edmundson wrote:It is one tank at a time


Bill if you have this valve handle pointed at the output it will draw from both tanks at that same time (all three ports are connected together). Granted I have not installed mine yet but that is how I understand it to work after looking at the valve construction.

If it's pointed at tank 1 you get tank 1 only
Tank 2 = tank 2
Plug = off but tank 1 and 2 are connected but nothing will happen assuming there is no syphoning action
Pointed to output you get tank 1 +2

In my case the filter and pump will be on the output side of that valve.
Jim
16' Ski Boat Restoration
17' Overnighter Sloop

I'd rather have a $h!tty meal than an $h!tty resume because a totally awesome resume will feed me steak one day - Steve Poltz

Brian
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Re: Twin Fuel Tanks - 4 Way Valve Installation

Postby Brian » Thu Sep 13, 2018 6:25 pm

Is there anything wrong with cross-connecting two tanks? I have brass T at the keel, fed by each tank, and supplying the engine. Shouldn't the two tanks equalize with the engine off, even if they don't draw equally while it's on? My fuel gauge switches from one to the other.

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Milhouse
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Re: Twin Fuel Tanks - 4 Way Valve Installation

Postby Milhouse » Fri Sep 14, 2018 9:13 am

Per uscg regs there shall be an anti syphon device at the tank output if the fuel line dips below the top of the tank any point.

I heard many people get rid of them... but it's supposed to prevent your bilge from filling with fuel if there is a line break.
Jim
16' Ski Boat Restoration
17' Overnighter Sloop

I'd rather have a $h!tty meal than an $h!tty resume because a totally awesome resume will feed me steak one day - Steve Poltz

Brian
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Re: Twin Fuel Tanks - 4 Way Valve Installation

Postby Brian » Fri Sep 14, 2018 10:28 am

Thanks. I can understand the USCG reg, which has to cover a myriad of situations and boat sizes. I would definitely be worried if it was hard-plumbed. But I have had a hose cross-connection on my ancient Land Rover ambulance for decades and it works just fine. On this boat, the lines and T are well-protected and visible. So a break is about as likely as a fuel tank rupture. I suppose I could go to armored hose, but that seems a bit much. An anti-siphon device would seem to negate the whole purpose of cross-connecting.

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hoodman
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Re: Twin Fuel Tanks - 4 Way Valve Installation

Postby hoodman » Fri Sep 14, 2018 7:37 pm

A boat is different than a car. On a boat the bilge can fill with gas or gas fumes. This can lead to bad things.


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