Fuel tank overfill warning

[robertager1962]

Hi all. I have a Southerly 105 whose fuel tank sits 3 feet below deck level and consequently has a very long filler and breather pipe. The tank has a sight tube visible from the engine bay. I will be renewing all the pipework in the next few days and wonder if anyone can recommend a method of preventing overfill of fuel so allowing the tank to be full without allowing the diesel to to be stored above the level of the tank ie not in the filler pipe. I have heard that you can buy a whistle to put on the breather but not sure how this would work. Any suggestions gratefully received.

 

[rogerthebodger]

Hi all. I have a Southerly 105 whose fuel tank sits 3 feet below deck level and consequently has a very long filler and breather pipe. The tank has a sight tube visible from the engine bay. I will be renewing all the pipework in the next few days and wonder if anyone can recommend a method of preventing overfill of fuel so allowing the tank to be full without allowing the diesel to to be stored above the level of the tank ie not in the filler pipe. I have heard that you can buy a whistle to put on the breather but not sure how this would work. Any suggestions gratefully received.

I fitted a float switch like this in the top a my diesel tanks, water tank and waste tank with a buzzer indicating when the tank is full.

 

[jdc]

The same subject crops up periodically, for instance http://www.ybw.com/forums/archive/index.php/t-327475.html

The float gadget looks good to me, or an optical sensor may be easier to fit.

 

[knuterikt]

The whistle will make a sound as long as air is pressed through the whistle. When fuel level reaches the whistle the sound stops. Liquid passing through will not make any sound.
should be installed just above tank top in breather line.

 

[pvb]

I'm a bit bemused by this. Most boats have the tank a metre or so below the filler. The filler pipe has to be securely fitted to the tank, so what does it matter if there's a few litres of diesel in the pipe? It won't stay there for long once the engine's going.

 

[NormanS]

When I hear it starting to gurgle in the breather, I know it's time to stop.

 

[GHA]

I'm a bit bemused by this. Most boats have the tank a metre or so below the filler. The filler pipe has to be securely fitted to the tank, so what does it matter if there's a few litres of diesel in the pipe? It won't stay there for long once the engine's going.

It can matter, breather isn't always above the filler, even when at the same height the breather can spit a little diesel onto the deck on some boats with fuel all the way up to the filler.

Little goes a long way.....

 

[johnalison]

When I hear it starting to gurgle in the breather, I know it's time to stop.

Mine has an anti-splash thingy in the filler pipe and it is usually easy to hear the fuel getting up to that level.

 

[NormanS]

It can matter, breather isn't always above the filler, even when at the same height the breather can spit a little diesel onto the deck on some boats with fuel all the way up to the filler.

Little goes a long way.....

Who in their right mind would have the breather lower than the filler?

 

[knuterikt]

Who in their right mind would have the breather lower than the filler?

The problem with some installations is the foam is forming and spilling out the vent before the filler tube is full.

 

[Ian_Edwards]

Who in their right mind would have the breather lower than the filler?

Although I agree with you in principle, but sometimes you don't get the choice when buying secondhand.

My southerly has the breather pipe plumbed in, with the breather on the transom about 1m below the filler cap, which is good in some ways, but you have to be very careful not to overfill the tank.

I normally listen the the sound of the diesel going into the tank and I can hear the sound of the diesel when it starts to "gulg" up the filler pipe, but this isn't foolproof. I can be very difficult to hear the sound of the diesel filling the running into the tank, when it's blowing a gale, or raining hard (or both).

 

[NormanS]

Although I agree with you in principle, but sometimes you don't get the choice when buying secondhand.

My southerly has the breather pipe plumbed in, with the breather on the transom about 1m below the filler cap, which is good in some ways, but you have to be very careful not to overfill the tank.

I normally listen the the sound of the diesel going into the tank and I can hear the sound of the diesel when it starts to "gulg" up the filler pipe, but this isn't foolproof. I can be very difficult to hear the sound of the diesel filling the running into the tank, when it's blowing a gale, or raining hard (or both).

Well I'm sorry, but I can't see anything "good" about having a fuel tank breather on the transom, where presumably you can neither see it or hear it, and 1m lower than the filler. I would change it.

 

[lpdsn]

When I'm going to fill up the tank completely, which isn't that often, I unscrew the inspection hatch, measure the level below the top and calculate the available volume.

 

[Plum]

Hi all. I have a Southerly 105 whose fuel tank sits 3 feet below deck level and consequently has a very long filler and breather pipe. The tank has a sight tube visible from the engine bay. I will be renewing all the pipework in the next few days and wonder if anyone can recommend a method of preventing overfill of fuel so allowing the tank to be full without allowing the diesel to to be stored above the level of the tank ie not in the filler pipe. I have heard that you can buy a whistle to put on the breather but not sure how this would work. Any suggestions gratefully received.

Why do you not want fuel to remain in the filler pipe after filling? It is quite normal although your breather must exit higher than, ideally significantly higher than, the filler. In my opinion, adding the device you are looking for will just add more complication.

Www.solocoastalsailing.co.uk

 

[robertager1962]

Thanks to all who responded. My issue is that I have experienced a possible leak and I can find no signs of where it came from. The tank (made of 2mm stainless) looks pristine. As it is only 15 years old, it is unlikely that it is a corrosion issue and I have inspected it thoroughly with a remote camera but can find nothing amiss. In November I drained the tank (250 litres) as a precaution and am now going to fit new breather pipe, filler pipe and sight tube pipe before refilling it. Before I experienced the leak I put in a full tank and had no idea how much fuel I was putting in and kept filling until the nozzle clicked out. Glugging of the breather may have been an audible signal but when I refilled in a very windy and rough Gosport refuelling pontoon, I could hear nothing. I would like to avoid fuel in the pipe if possible. I don't have an inspection hatch in the tank so this makes adding a float switch difficult. I may add one at a later date. I am going to try the whistle out as it seems easy to fit. As always it is good to get a cross section of responses from practical people, helping to give me food for thought.

 

[thinwater]

Mine has an anti-splash thingy in the filler pipe and it is usually easy to hear the fuel getting up to that level.

Parker/Raycor Lifeguard? Works pretty good IME.

 

[Plum]

Thanks to all who responded. My issue is that I have experienced a possible leak and I can find no signs of where it came from. The tank (made of 2mm stainless) looks pristine. As it is only 15 years old, it is unlikely that it is a corrosion issue and I have inspected it thoroughly with a remote camera but can find nothing amiss. In November I drained the tank (250 litres) as a precaution and am now going to fit new breather pipe, filler pipe and sight tube pipe before refilling it. Before I experienced the leak I put in a full tank and had no idea how much fuel I was putting in and kept filling until the nozzle clicked out. Glugging of the breather may have been an audible signal but when I refilled in a very windy and rough Gosport refuelling pontoon, I could hear nothing. I would like to avoid fuel in the pipe if possible. I don't have an inspection hatch in the tank so this makes adding a float switch difficult. I may add one at a later date. I am going to try the whistle out as it seems easy to fit. As always it is good to get a cross section of responses from practical people, helping to give me food for thought.

Before doing all that work I would recommend doing a pressure test. Block all fuel pipes/breather except one that you can use to fit a pressure gauge and a tire valve then use a bike pump to apply 15psi and listen for the leak. I made up this arrangement recently to test my cooling system.

Www.solocoastalsailing.co.uk

 

[Quandary]

I am interested in a practical answer from those of you who advocate extending the breather to above the filler, which in my case (and many others?) is at deck level.
Where do you terminate it?

 

[pvb]

Thanks to all who responded. My issue is that I have experienced a possible leak and I can find no signs of where it came from. The tank (made of 2mm stainless) looks pristine. As it is only 15 years old, it is unlikely that it is a corrosion issue and I have inspected it thoroughly with a remote camera but can find nothing amiss. In November I drained the tank (250 litres) as a precaution and am now going to fit new breather pipe, filler pipe and sight tube pipe before refilling it. Before I experienced the leak I put in a full tank and had no idea how much fuel I was putting in and kept filling until the nozzle clicked out. Glugging of the breather may have been an audible signal but when I refilled in a very windy and rough Gosport refuelling pontoon, I could hear nothing. I would like to avoid fuel in the pipe if possible. I don't have an inspection hatch in the tank so this makes adding a float switch difficult. I may add one at a later date. I am going to try the whistle out as it seems easy to fit. As always it is good to get a cross section of responses from practical people, helping to give me food for thought.

If you have a leak, the answer is to sort it out, not paper over the cracks by some other method.

 

[pvb]

I am interested in a practical answer from those of you who advocate extending the breather to above the filler, which in my case (and many others?) is at deck level.
Where do you terminate it?

The breather usually won't be above deck level; it's sufficient for it to be close below deck level. It will indicate when the filler pipe is full. A breather above deck level is almost certain to discharge some diesel on to the deck, which is to be avoided.