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MBA Marine

Fuel lines

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I'm pro the boat saftey scheme but im currently bringing a boat up to standard and i have a grievence.

One (of many) thing that has failed is fuel lines, im all for using the iso 7840 hose that we are to use (or copper) but in this case i think descresion should be used. The boat a Nimbus with twin volvo engines built i would guess 90's has long complicated pipe runs, current hoses are all pre-made on bench crimped at each end of every hose, the hoses are orgional and are as good as the day they were installed but are lacking the iso7840 number on the side.

The boat has failed quite rightly on many things and the owner set for quite a large bill that i can do nothing about, but it just seems wrong that i have to remove good work and the customer has to pay for expencive hose (and cheap labour :grin: ) that surley wasnt necessary, the hose was a good quality fuel hose, i know it all comes down to the fire risk but i really doubt the 7840 will last any longer than what was in in a fire, I might do a (controled) bench test and see if one is anymore flame resistant than the other.

Rant over!

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Had the same problem with a gm v8 diesel,the oil spill lines (returns),from the injecters where not to78 ect,took 2 rulings from the EA to sort it out,luckily i only had to join the two banks of cylinders together,and fit a non-return valve before the pipe met the main return,a lot of hassle for basicly nothing!!

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I guess they have to draw the line somewhere, and in the case of such vital components as fuel hoses on what sounds like a petrol boat (?), the numbering not only clarifies the quality, but also the age.

I've had an even more apparently "unreasonable" situation with a previous boat that failed on the fuel tank filler pipe. It was a section of 2" diameter hose that was only 6" long, and that particular short piece didn't have the number on it. The examiner told me a receipt would have been an acceptable alternative, but I didn't have that either.

When I replaced it, the shortest I could get was a half metre, and I made damn sure that piece had a marker on it, and I placed that short piece in full view ! :)

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I guess they have to draw the line somewhere, and in the case of such vital components as fuel hoses on what sounds like a petrol boat (?), the numbering not only clarifies the quality, but also the age.

I've had an even more apparently "unreasonable" situation with a previous boat that failed on the fuel tank filler pipe. It was a section of 2" diameter hose that was only 6" long, and that particular short piece didn't have the number on it. The examiner told me a receipt would have been an acceptable alternative, but I didn't have that either.

When I replaced it, the shortest I could get was a half metre, and I made damn sure that piece had a marker on it, and I placed that short piece in full view ! :)

This boat is diesel, with regard to your filler, if your petrol then filler and breather hoses must be 7840 but if your diesel then the filler and breather pipe only have to be in sound condition, i would asume they would have to be 7840 in engine bay, i will read up on that bit.

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My reading of the BSS specs leads me to understand that the requirements for all fuel flexible hose, (filler pipes and fuel feed lines) is exactly the same for petrol or diesel as far as ISO 7840 goes.

That fuel filler pipe was on a previous boat of mine, which was diesel....

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My reading of the BSS specs leads me to understand that the requirements for all fuel flexible hose, (filler pipes and fuel feed lines) is exactly the same for petrol or diesel as far as ISO 7840 goes.

That fuel filler pipe was on a previous boat of mine, which was diesel....

You may find the filler and breather have rules on diesels have been relaxed, i always had changed them for ISO7840 but last time i talked with examiner about it, he said the just have to be in good condition. Petrol's do have to be ISO7840

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"All hose used in the fuel system must be fire resistant to at least 21/2 minutes, as specified in the internationally agreed marine fuel hose Standard (BS EN ISO7840)"

from http://www.boatsafetyscheme.com/site/fl ... ses_42.asp

with no petrol/diesel differentiation.....

2.2.3/R REQUIREMENT

Fuel must not be retained in the filling hose, as this could cause

blow back when refuelling.

Is the fuel filling line self-draining so that fuel is not retained

and is it free of kinks or other restrictions?

Check the fall of each fuel filling line.

Check for any kinks or other obvious restrictions in fuel filling lines

where they can be seen or reached.

Fuel filling lines must be ‘self-draining’ i.e. fall continuously from the

filling point to the fuel tank connection so that fuel is not retained.

Fuel filling lines must not be kinked or restricted.

Note – Fuel filling lines must not have their internal bore diameter

restricted to less than 31.5mm (11â„4 in).

Damaged or deteriorating fuel filling lines could fail and result

in a leak that could form a potential fire, explosion, or pollution

hazard depending on the fuel used. In the case of petrol, hose not

designed specifically for that fuel can fail rapidly. Indeed all fuel oils

can ‘attack’ unsuitable materials.

Is the material of the fuel filling line suitable and in good condition?

Check the material and condition of fuel filling lines, which can

be seen or reached.

Check the markings on any fuel filling hose.

Fuel filling lines must not show signs of fuel leaks, damage,

or deterioration.

Fuel filling hose must be marked as suitable for the fuel in use

or supported by an appropriate declaration.

Notes – diesel filling hose in good condition may be accepted

without marking or declaration provided it can be examined over

its entire length.

Enough suitably marked diesel filling hose, or enough petrol hose,

must be accessible to make a reasonable assessment as to the

hose’s general condition.

2.3.2/R REQUIREMENT

Best practice b

We recommend that you use hoses marked with BS EN ISO 7840

although hoses marked with SAE J 1527, DIN 4798 or marked

with the type of fuel in use are acceptable.

Notice where the type of hose is specified its the 'best practice' section not a you must do, REQUIRMENT!

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I bet this 7840 hose has suddenly shot up in price since it has become a legal requirement?. I can`t help thinking that when EVERY boat has this latest 7840 hose fitted, then the authorities will AGAIN change the spec and call for ALL fuel lines to be replaced with yet another legally required different spec hose. Or am i being just a tad synical YET AGAIN?.

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Notes – diesel filling hose in good condition may be accepted without marking or declaration provided it can be examined over

its entire length.

You're quite right MBA, I apologise. My cast iron quote from the current official BSS specs is indeed contradicted by your quote from another part of it.

It's even further convoluted by the subsequent statement

"Enough suitably marked diesel filling hose, or enough petrol hose, must be accessible to make a reasonable assessment as to the hose’s general condition."

So you can only have unmarked diesel filler hose if every inch of it can be inspected, unlike marked hose (which could have a hidden damaged section !) :roll:

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Clanny's petrol filler and breather lines are marked only with a red band, 3 years ago this was deemed acceptable thanks to Sealine sending a declaration that it was suitable for the fuel in use and because a sufficient amount could be inspected to judge its general condition.

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Clanny's petrol filler and breather lines are marked only with a red band, 3 years ago this was deemed acceptable thanks to Sealine sending a declaration that it was suitable for the fuel in use and because a sufficient amount could be inspected to judge its general condition.

You got a little lucky there. Sealine are never going to say that the hose they used in that application was unsuitable are they, but notice they did not say it was the exact grade that is required! Also its doubtfull that the person in the office whom gave the declaration had a clue what hose was fitted. I would suggest you try and use the same examiner next time otherwise you might be back appealing the same piont again next time.

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They did actually send a certificate and an explanation that the red band was the marking but the certificate did not quote any of the required numbers.

I may well change it this year as part of routine maintenance given that the boat is coming up to 18 years old but the hoses do appear to be in perfect condition.

I had already changed all flexibles from the isolators to the engine bay for correctly marked items.

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Incidentally of the hoses within the bay 2 had been changed to ISO grade the others were original. The graded ones had the steel braid under a yellow PVC skin, both of these on inspection were showing signs of failure where the braid had rubbed on the inner hose. The original and unmarked were perfect. Maybe another case of change being pushed through for changes sake, well intentioned but dangerous.

Having said that the new ISO hoses I fitted did seem thicker and better so maybe just a change over problem.

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I had exactly the same situation with our BMW petrol engine and the boat passed her first BSS inspection with the manufacturers hoses.

The tester passed them on the basis that they were in sound cindition, crimped and also flex wire armoured. When the time to renew the BSS came, a different tester failed them and got me to fit the ISO rated fuel lines. He did comment though that he felt the new hoses were not as safe as the originals!

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The graded ones had the steel braid under a yellow PVC skin, both of these on inspection were showing signs of failure where the braid had rubbed on the inner hose.

You have me thinking now, but I'm pretty sure (though I have been known to be wrong :naughty: ), that a layer of steel braiding is not a requirement of ISO 7840 hose.

This photo shows the tubing in my engine bay with yellow hose to the pump and a section of black hose from it, to the carb. Both are marked as 7840 and neither has any metal braid in it.

post-669-136713879758_thumb.jpg

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It also cost me a lot of money when I bought my Seaward twin diesel to the Broads. All the fuel lines had to be replaced because they weren't marked "correctly". This was expense that was unnecessary in my view and that of Seaward Marine, who are internationally renowned for building exceptionally seaworthy boats. Bl***y irritating jobsworth stuff from the BSS regs.

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You have me thinking now, but I'm pretty sure (though I have been known to be wrong :naughty: ), that a layer of steel braiding is not a requirement of ISO 7840 hose.

This photo shows the tubing in my engine bay with yellow hose to the pump and a section of black hose from it, to the carb. Both are marked as 7840 and neither has any metal braid in it.

Alot of those steel braid with the yellow outer are failing now if you have them they are normaly short lengths at the engine and are best changed now, the pure rubber ISO7840 is good hose and last for a very long time, Its quality i never questioned.

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