Diesel tank air vent

[snowbird30ds]

On my boat (albeit a stinky) due to a sharp bend in the filler I had to fit a second 3\4" id breather or most waterside fuel pumps would cause it to fob and erupt out of the filler, if fuel gushes in the filler quick enough air has to get out elsewhere so a breather in the filler would be useless.

 

[Refueler]

While some have been basking in wall-to-wall summer sunshine, at this end one has been enduring 40-knot wall-to-wall winter drizzle. There has been quite some reluctance to clamber under the boat's tarpaulin - dribbles and runs of cold water runoff down the back of the neck - to delve among the shelves for the battered and distinctly-well worn filler vent thingy.

The team nagging finally won. Here it is....

It WAS mounted vertically through the narrow aft deck, where it was physically vulnerable and likely to be inundated in heavy weather. That space is now occupied with something more important, hence I need a new and better home for something similar.

There's an existing flexible plastic pipe, and I could readily extend that as suggested above. I'll seek a space where I can effect a 'vent loop' as high as practicable.

That style vent is actually designed for the gauze to face DOWNward .... not horizontal ... usually fitted into a vertical surface.

But anyway - with an inverted U any orientation of the fitting would work ....

mmmm yes a good clean up would be nice !

 

[NormanS]

If you google you will find all sorts of filler and caps to meet every need.

I chose this one 'cos its cheap (and I assume it might be available in Europe) as its marketed by Plastimo.

Plastimo Plastic Fuel Deck Filler With Vent Silver | Waveinn

Our filler and cap on Josepheline was flush mounted, had a vent and worked perfectly when the seas were breaking over the cabin roof.

Many fillers, but not all, with cap, claim to incorporate a vent within the flush mount of the device though I noted one device had a spigot (suggesting the vent was a hose).

Jonathan

The one in your link isn't a flush fitting.

 

[Neeves]

The one in your link isn't a flush fitting.

At least you used the link

I did not say it was a flush fitting - I said I offered the link because the product was cheap (and available in Europe). I thought it would have less relevance to quote a US or Australian product.

Jonathan

 

[PaulRainbow]

You think? On all the boats that I've had anything to do with, the vent/breather/overflow has always been above the filler.

My fillers are flush fitted in the side decks, the breathers are about a foot below them, in the sides of the boat.

 

[vyv_cox]

My filler cap is on top of the cockpit coaming, with the tank immediately below just a few inches down. The breather is on the angled aft face of the coaming, maybe two inches below the filler cap. It is of the type shown in post #17, mounted with the gauze downwards. If the tank overflows on filling the diesel runs onto the deck, where it can be wiped up.

The hose to it is very short, with no space for an upward loop. The location of the breather is such that any water ingress is almost impossible.

 

[zoidberg]

Thanks. There are multiple options available via the various specialist retailers such as ASAP Supplies and Force4.

Here's one shiny example, in brass....

This is not the most important issue, not a 'deal-breaker', in my quest but, as I'd encountered quite a few bodges on this boat along the way, I thought to find what others thought and did re 'breathers'. It's a diesel system, of course, so 'flame protection' is not a concern.

As they say in all political processes these days, 'Lessons have been learnt'.

 

[NormanS]

At least you used the link

I did not say it was a flush fitting - I said I offered the link because the product was cheap (and available in Europe). I thought it would have less relevance to quote a US or Australian product.

Jonathan

In post 20, you said that the one that you had on your boat was "flush mounted".
Does that mean it was flush with the deck or not?
In the past, I have had broken toes through tripping over 'sticky-up' bits, in bare feet, so when I say a "flush" fitting, I mean a flush fitting. I still can't imagine a fitting flush with the deck which can incorporate a breather.

 

[Refueler]

In post 20, you said that the one that you had on your boat was "flush mounted".
Does that mean it was flush with the deck or not?
In the past, I have had broken toes through tripping over 'sticky-up' bits, in bare feet, so when I say a "flush" fitting, I mean a flush fitting. I still can't imagine a fitting flush with the deck which can incorporate a breather.

There used to be a flush fitting - where the screw in 'plug' has a small hole in it ... below the hole was a diaphragm that created a convoluted route to stop water entering ... but vernting from tank was fine ...

Similar to the caps on various garden gear - but flush.

 

[NormanS]

There used to be a flush fitting - where the screw in 'plug' has a small hole in it ... below the hole was a diaphragm that created a convoluted route to stop water entering ... but vernting from tank was fine ...

Similar to the caps on various garden gear - but flush.

Well, maybe, but garden gear doesn't usually have water flowing over it. If I have a deck mounted flush filler, I will always have the breather in a higher and more protected place

My fillers are flush fitted in the side decks, the breathers are about a foot below them, in the sides of the boat.

My fillers are flush fitted in the side decks, the breathers are about a foot below them, in the sides of the boat.

Yes, but your boat doesn't heel over like a boat under sail.

 

[lustyd]

Yes, but your boat doesn't heel over like a boat under sail.

Every BenJenBav I can remember has exactly this arrangement, hence my earlier comment.

 

[RunAgroundHard]

... I could mount it up inside the hollow grp stern coaming, on/crossing the centreline. But, would I be better keeping it all inside the stern locker 'upstand' - or protruding as before, but about 3-4 inches higher?

Thoughts?

I would fit as per your suggestion but keep the vent outlet outside. When I fill there is a degree of air rushing out of the vent as well as a diesel smell, hence I would not want that inside my boat. In extremis, if knocked down, over, you don't really want diesel pouring out the vent inside. I think from your other posts that the Jester Challenge is a possibility, so knock down might be a higher risk than most.

Mine (2 x tanks) are on the coaming of the cockpit, one each side. On this boat, they don't splash diesel when I fill to the top and are about 8 to 10 inch above the deck. However, on another boat, same model, they did, always spurted a bit of diesel foam when the tank got full. Maybe diesel is less foamy these days.

 

[Refueler]

Well, maybe, but garden gear doesn't usually have water flowing over it. If I have a deck mounted flush filler, I will always have the breather in a higher and more protected place

The description was then supported by quoting the garden gear ... no-one was suggesting using garden gear on the boat ... BUT water ingress is also a matter to prevent whatever gear ....

 

[thinwater]

That style vent is actually designed for the gauze to face DOWNward .... not horizontal ... usually fitted into a vertical surface.

But anyway - with an inverted U any orientation of the fitting would work ....

mmmm yes a good clean up would be nice !

Exactly.

Perko even sells a riser kit, for fittings that were installed on the flat.
Perko 0540DPRBLK | Fisheries Supply

I wouldn't give 10c for the odds of this working if a wave washed over. Cats and power boats, probably OK. Monos ... it needs to be a wave-free, knock-down-free location. IMO.

On my cat, the vent goes down through the bridge deck, after a Raycor Lifeguard and a ~ 36 rise (8" higher than the filler). Zero chance of ingress short of sinking. No chance of overflow. No rain either, since it is under the deck.

 

[PaulRainbow]

Yes, but your boat doesn't heel over like a boat under sail.

Hopefully not, but i don't see the relevance, my previous boat, a Westerly Discus, had the breather (One like in post #27) in pretty much the same place, just below the rubbing strake.

 

[NormanS]

Hopefully not, but i don't see the relevance, my previous boat, a Westerly Discus, had the breather (One like in post #27) in pretty much the same place, just below the rubbing strake.

Not doubting you, but I find it very surprising. So what stopped or stops water getting in?
At times I have water sloshing along the deck, and therefore flowing over the deck filler. The breather, however, is safely a couple of feet higher, mounted on the side of the deck saloon.

 

[PaulRainbow]

Not doubting you, but I find it very surprising. So what stopped or stops water getting in?
At times I have water sloshing along the deck, and therefore flowing over the deck filler. The breather, however, is safely a couple of feet higher, mounted on the side of the deck saloon.

It was one like post #27, with the holes facing down, just below the rubbing strake. Never had any water get in, never gave it a thought.

 

[Refueler]

It was one like post #27, with the holes facing down, just below the rubbing strake. Never had any water get in, never gave it a thought.

Did it have an inverted U in the pipe ?

 

[PaulRainbow]

Did it have an inverted U in the pipe ?

Honestly, can't remember.