Is a fuel-water separator essential?

A1Sailor

A1Sailor

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Interested in a boat with a relatively new ~10HP Vetus diesel engine, which has an "integral" fuel filter - probably called the primary filter! The one that screws onto the engine. There is no fuel water separator +/- filter between the tank and the engine. I thought a fuel water filter was essential, but seller says the engine has run for 10 years without any problems.
It isn't a major problem adding one after purchase - but am I over-reacting? My diesel car doesn't have one - but the diesel in the tank get's turned over a bit more rapidly than occasional use of a yacht engine.
A surveyor will be able to advise in due course...

Thanks.
 
Well from the amount of water I've drained out of mine, I would say yes, they are a very good idea!

Our boat is fitted with a Racor unit which seems pretty well engineered.
 
Having had a series of breakdowns at sea due to contaminated fuel I would suggest a primary filter with a water seperator and, most importantly, a bowl give a visual reference to what is going on, is a must-have.
The primary filter is a first line of defence but it is not much good if you can't get rid of the nasties before they become engine-stopping, ie by draining off. That is not possible with most engine-mounted spin-on CAV filters.
I am now in the process of upgrading my primary to a Parker Racor filter which has a circulation system for separating water and bits as well as fine filtering to 10 micron, replacing a standard Delphi.
 
I went to clean my water seperator a couple of weeks ago and found a lot of diesel bug in it. When I checked the primary filter it was clean. So it seems to do a important job there.

Martin
 
davidej said:
I've always had one and never ever found any water in it.

That is not to say it couldn't happen one day!
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+1

I have a copy of the BUKH engine installation guide and it shows a pipe run direct from the tank to the lift pump with no intervening filter/separator
 
Off topic is cool!

ghostlymoron said:
Slightly off topic but is it also necessary to have a Vetus strainer? I currently have just a coarse grid over the cooling water inlet.
Click to expand...

Thanks for the responses. Essential in my view to have some kind of strainer between the sea water intake seacock and the impeller. The boat in question has an "external coarse grid" to stop sharks getting in, but also one of these:
waterfilter.jpg

Almost big enough for a small shark to swim around in..!
 
A1Sailor said:
Thanks for the responses. Essential in my view to have some kind of strainer between the sea water intake seacock and the impeller. The boat in question has an "external coarse grid" to stop sharks getting in, but also one of these:
waterfilter.jpg

Almost big enough for a small shark to swim around in..!
Click to expand...

Our Dufour 365 came new without a sea water strainer. I was surprised by the lack of it.
 
ghostlymoron said:
Slightly off topic but is it also necessary to have a Vetus strainer? I currently have just a coarse grid over the cooling water inlet.
Click to expand...

Grids are "out of fashion" these days - argument being that they can block up externally but cannot be cleaned easily internally. Normal practice now is a straight inlet with a ball valve and a vertical pipe to a strainer above the waterline, then down to the pump. The strainer can be cleaned without closing the valve and if the intake blocks you can "rod" it clear through the strainer bowl. You can also prime the water pump if needed through the strainer or run the engine out of the water with a hose into the strainer.

Not always easy to find a good location on an existing installation, but when you see the amount of fine muck the strainer stops you can see why they are popular.
 
Thanks Gordon et al

Gordonmc said:
Having had a series of breakdowns at sea due to contaminated fuel I would suggest a primary filter with a water seperator and, most importantly, a bowl give a visual reference to what is going on, is a must-have.
The primary filter is a first line of defence but it is not much good if you can't get rid of the nasties before they become engine-stopping, ie by draining off. That is not possible with most engine-mounted spin-on CAV filters.
Click to expand...

This is kind of my thought too. Wanted to make sure I wasn't being over cautious! Clearly, though, you can get away with not having a fuel/water separator/filter assembly, though.

I was just a bit surprised to find a boat that had no protection against water reaching the injectors - and dependant solely on the CAV filter (the one on the engine) to filter out the nasties - good word.
I used to be indecisive but now I'm not so sure...
 
Force 4 sell a cheaper one. See p62 of their catalogue. ASAP Supplies also have a range, including Vetus. You will find the Vetus 330 probably the most popular on small engines, but you need to get the correct hose size as the spigots are only one size (different part nos for different hose sizes).
 
A1Sailor said:
Interested in a boat with a relatively new ~10HP Vetus diesel engine, which has an "integral" fuel filter - probably called the primary filter! The one that screws onto the engine. There is no fuel water separator +/- filter between the tank and the engine. I thought a fuel water filter was essential, but seller says the engine has run for 10 years without any problems.
It isn't a major problem adding one after purchase - but am I over-reacting? My diesel car doesn't have one - but the diesel in the tank get's turned over a bit more rapidly than occasional use of a yacht engine.
A surveyor will be able to advise in due course...

Thanks.
Click to expand...

My previous boat had a vetus 10hp engine, much as you describe. The primary/main engine fitted filter has a water separator function as part of the filter. You should find a plastic nut on the bottom of the filter casing, which the maintenance guide tells you to periodically release to drain any water/debris from.
 
I have a Vetus like this and I retrofitted a CAV filter/separator mainly because access to the engine filter is very tight and it would be a bitch of a job to do in an emergency. Its hard enough when performed at lesiure in the winter.

Also CAV filters are cheap so I leave the engine filter much longer and change the CAV filter more regularly.
 
A1Sailor said:
Interested in a boat with a relatively new ~10HP Vetus diesel engine, which has an "integral" fuel filter - probably called the primary filter! The one that screws onto the engine. There is no fuel water separator +/- filter between the tank and the engine. I thought a fuel water filter was essential, but seller says the engine has run for 10 years without any problems.
It isn't a major problem adding one after purchase - but am I over-reacting? My diesel car doesn't have one - but the diesel in the tank get's turned over a bit more rapidly than occasional use of a yacht engine.
A surveyor will be able to advise in due course...

Thanks.
Click to expand...
All cars have fuel water seperators integral to the fuel filter body-water collects at the bottom of filter and it should be drained regularly until clean diesel runs out.
As far as I am aware this is true of all diesel filters.Having a glassbowl one is usefull for a visual check but is considered dangerous by British Waterways if you need a Boat Safety Certificate and for on road use in cars etc.
 
You learn something new on here every day!

If you go to: http://www.abcpm.co.uk/downloads/engines/vetus/M202.pdf the lower left diagram has a filter which says VETUS on it with a funnel shaped bit at the bottom with what could be a drain - must unlike a "standard" CAV filter. If only they had taken a picture of the other side of the engine we could see it!
Page 35-36 at http://www.vetusweb.com/manuals/files/Vetus_M-Series/340402.01 r01 12-07 M4_55 EN.pdf however has some B&W images and a narrative. I can see how getting access to the starboard side of the engine towards the rear might be interesting - and that an additional fuel water separator might be useful; as long as it didn't cause safety concerns.

Thanks guys & gals.
 
I woulfd fit a Racor filter with a clear bowl on the bottom in the pipe leading to the engine filter. Make sure it it slightly finer than the engine filter then you know which one is blocked if the engine cuts out. It is imperative to fit a water catchment filter because water doesn't compress and will damage the injectors.
 
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