Extending fuel pipe run

[stownsend]

Afternoon

I'm considering installing a duel fuel filter system with change over valve - nothing special just 2 CAV style fuel filters as mine is located in a difficult place to reach (all within 4 foot or so of the engine) The plan is to run the fuel pipe an extra 1 m to the heads where the 2 fuel filters will be mounted and with associated valves etc... and back again the engine filter.

Would increasing the run cause any issues ?

Cheers

Stu

 

[pvb]

Shouldn't be an issue at all.

It's worth considering the valve arrangements carefully. Ideally, you need to be able to close off both the inlet and the outlet of each filter - in this way, you can change a blocked filter whilst running the engine on the second filter. Depending on your tank location, you may need to prime the new filter so filter housings with integral primers are an advantage.

 

[stownsend]

Thanks for the reply, thinking of having something like this - post 6

http://www.ybw.com/forums/showthread.php?326970-Dual-Fuel-Filters&p=3693292#post3693292

Cheers

Stu

 

[David2452]

Length can be an issue, more so when you are pulling the fuel rather than pushing it as you will be with a lift pump on an engine, however a couple of metres should not be an issue, try to keep the hose or tube to the minimum bore commensurate with adequate flow and there shouldn't be an problem. Engine, heater & genny manufacturers publish fuel supply line recommendations and you may well either have it in your manual already or be able to find it online.

 

[pvb]

Thanks for the reply, thinking of having something like this - post 6

http://www.ybw.com/forums/showthread.php?326970-Dual-Fuel-Filters&p=3693292#post3693292

That's fine, except it doesn't allow you to prime a new filter without stopping the engine.

 

[stownsend]

may be a primer valve with non-return air / blow off valve after the filter before the y join ?

cheers

stu

 

[pvb]

may be a primer valve with non-return air / blow off valve after the filter before the y join ?

But where does the fuel come from if the engine's running on the other filter?

 

[stownsend]

true, didn't think of that - 2 options them - rethink of how it can be done without stopping the engine or stop the engine prime and carry on ..

Cheers

Stu

 

[jneale]

I have a 2 tank setup and use a gas fitting to switch the following. Port tank to Engine, Stbd tank to Engine. Both tanks to Engine. Port tank to Stbd tank (no connx to engine). The fuel return goes only to the STBD tank (which is the default) and the Port tank is used for extra fuel storage. When the STBD tank runs low, I transfer fuel from Port to Stbd using an electric inline fuel pump. When changing filters etc, I can also prime them by pumping fuel from Port to Engine. The lift pump can also suck fuel through this electric pump if necessary. Hope this helps

 

[prv]

Worth noting that you don't have to use filters with built-in priming pumps - I have an outboard-style rubber bulb pump in the fuel line from my tank (just after the tank shut-off valve). This works very well for priming the system - I can install a new filter without pre-filling it, then open the bleed screw fully and a couple of firm squeezes on the pump fills the bowl. Half-close the bleed screw (to stop it squirting a major jet everywhere) and then squeeze more cautiously on the pump to push out the last of the air, close the bleed screw and wipe up the dribble of fuel from on top. Job done and the engine will now run faultlessly.

I do have the plumbing for quick changeover of filters, but it's an off-the-shelf system which doesn't have the ability to change while still running. I'm ok with this, the idea being that the ready-use filter gets you out of immediate trouble (the narrow harbour entrance or whatever) and you stop to change the old one ASAP afterwards. As you can see above, it's a fairly quick job on Ariam, in an accessible and well-lit space.

Pete