Diesel fuel lines, filters and the rules ...

[Alan de Enfield]

21 minutes ago, T_i_m said:

Getting closer to properly re-fitting the fuel pump and the new filter so from what you said and the BSS indicates, would I be right in thinking that if the hose run was short, it could be all in rubber?

 

If so, I have 1m of 5mm ID ISO 7840 compliant hose but only 50% is actually marked at at all? Does that mean I can only use a bit as long as it has the markings on it? ;-(

 

 

No it simply means you cannot use a cut length that is not marked.

You can leave it as one length, or use the marked section.

[T_i_m]

26 minutes ago, Alan de Enfield said:

 

 

No it simply means you cannot use a cut length that is not marked.

You can leave it as one length, or use the marked section.

Right, that was sort of what I was saying Alan, 'of course' if a length of hose has markings on it somewhere than the rest of the hose will comply but you are saying once I cut it in half and so end up with an unmarked bit, it (the unmarked bit) can't be used?

 

I see there is the possibility of a declaration from a 'Manufacturer or supplier ...'  that should cover it so I might ask if they can supply such and put it in the boat manual I'm building for him.

 

AFAIK, none of the existing short rubber couplings have any markings and it's been though several BSS's like that?

 

 

Edited May 9 by T_i_m

[pearley]

On 27/03/2025 at 12:02, matty40s said:

Not gravity fed, just a common engine install, most modern engines narrowboats have this arrangement.

Yes..

What is the thread size of the input and output

[T_i_m]

1 minute ago, pearley said:

What is the thread size of the input and output

On that unit it looks like 3/8" BSP but on the one I have it's 1/4" BSP?

[LadyG]

Deleted

Edited May 9 by LadyG

[T_i_m]

2 minutes ago, LadyG said:

Im pretty sure the gas hose in my  locker is unmarked,  and my spare is too, I want it replaced next time I can find a competent person with long arms and strong wrists.

I think I was supposed to (Or it was recommended one did) replace the gas hose on my (folding) caravan every 5 years or something and sooner if you saw any issues (kinking, abrasion, cuts etc) and I was happy to do so.

[LadyG]

12 hours ago, T_i_m said:

Right, that was sort of what I was saying Alan, 'of course' if a length of hose has markings on it somewhere than the rest of the hose will comply but you are saying once I cut it in half and so end up with an unmarked bit, it (the unmarked bit) can't be used?

 

I see there is the possibility of a declaration from a 'Manufacturer or supplier ...'  that should cover it so I might ask if they can supply such and put it in the boat manual I'm building for him.

 

AFAIK, none of the existing short rubber couplings have any markings and it's been though several BSS's like that?

 

 

From my days in manufacture/supply, if a Certificate of Compliance was required, this would be charged. I think we issued a Certificate to China Air on their first sales transaction, for a tyre gauge, but I don't remember any other. It was not generally offered as an option and none of our hose had printing on it.

Edited May 10 by LadyG

[pearley]

12 hours ago, T_i_m said:

On that unit it looks like 3/8" BSP but on the one I have it's 1/4" BSP?

Thanks. The one I've bought is probably the larger one.

[T_i_m]

1 hour ago, LadyG said:

From my days in manufacture/supply, if a Certificate of Compliance was required, this would be charged. I think we issued a Certificate to China Air on their first sales transaction, for a tyre gauge, but I don't remember any other. It was not generally offered as an option and none of our hose had printing on it.

So how does it work with the BSS where fuel hose markings are concerned? I mean, I bought 2 x 500mm lengths (that come as one) and so I know that at least 50% of that hose isn't marked. Even then I didn't get all the text.

 

"mm ISO 7840 2013  A1    CE RINA Cert No. DIP067721XT/001  -  SAE J 1527  USCG TYPE A1 R1 LLOYD'S Cert No. 02/00030(E3) 3Q2021 (LOT 137815)".

 

That lot covers 550mm of 1000mm of hose and that's not all of it.

 

So, say we were going to cut it into several short lengths to join: tank to copper pipe, copper pipe to filter, filter to copper pipe, copper pipe to pump, pump to copper pipe, copper pipe to heater ... 6 x 60mm lengths, now many would conform to the BSS?

 

I also note that suggests the hose conforms to the ISO 7840 2013 and the current standard is 2021? That suggests that the hose was made before 2021 or it would have been marked with the latest std?

 

So, does that really mean if you aren't using enough of it to be sure to have a bit with the marking (and the right marking) on it you can't use it on a BSS tested boat, as has been suggested?

[Alan de Enfield]

7 hours ago, T_i_m said:

I also note that suggests the hose conforms to the ISO 7840 2013 and the current standard is 2021? That suggests that the hose was made before 2021 or it would have been marked with the latest std?

 

 

I think you may be confusing dates with approval authorities :

 

ISO = the international standard 7840 (issue 2013)

CE = Conformite European

RINA = Royal Institute of Naval Architects

SAE = Society  of Automotive Engineers (USA)

USCG = US Coast Guard

Lloyds = Lloyds Bureau of Shipping

 

3Q2021 = manufactured 3rd quarter 2021, batch number 137815

 

This is something, as a company, we had to do on a regular basis as we supplied our standard products all over the world to many different countries and customers who required specific product approvals.

 

Another set we had to get approved for marine use was :

 

BV = Bureau Veritas (France)

DNV = Det Norske Veritas (Scandinavia)

 

Edited May 10 by Alan de Enfield

[T_i_m]

11 minutes ago, Alan de Enfield said:

 

I think you may be confusing dates with approval authorities :

 

ISO = the international standard 7840 (issue 2013)

CE = Conformite European

RINA = Royal Institute of Naval Architects

SAE = Society  of Automotive Engineers (USA)

USCG = US Coast Guard

Lloyds = Lloyds Bureau of Shipping

 

3Q2021 = manufactured 3rd quarter 2021, batch number 137815

 

This is something, as a company, we had to do on a regular basis as we supplied our standard products all over the world to many different countries and customers who required specific product approvals.

 

Another set we had to get approved for marine use was :

 

BV = Bureau Veritas (France)

DNV = Det Norske Veritas (Scandinavia)

 

It doesn't take much to confuse me Alan. 😉

 

How many people here have had a BSS inspector question the spec of a bit of unmarked rubber fuel hose I wonder? I mean, I'm trying to feel a feel of just how much of an issue this is in the real world as I can't see how I can gent better marked hose and don't want to be the cause of a BSS fail etc.

[Jen-in-Wellies]

40 minutes ago, T_i_m said:

It doesn't take much to confuse me Alan. 😉

 

How many people here have had a BSS inspector question the spec of a bit of unmarked rubber fuel hose I wonder? I mean, I'm trying to feel a feel of just how much of an issue this is in the real world as I can't see how I can gent better marked hose and don't want to be the cause of a BSS fail etc.

I've seen it happen. Not my boat, but some do check and fail boats for this. If it is a short length, try and make sure it has the approval marking on it.

[T_i_m]

Just now, Jen-in-Wellies said:

I've seen it happen. Not my boat, but some do check and fail boats for this. If it is a short length, try and make sure it has the approval marking on it.

That's the issue Jen, if we need 5 short rubber connections between the various bits (filer / pump / heater), from the 1m length of hose I have here only one would have 'ISO 7840' marked on it?

 

Given that only 50% of the 1m has anything written on it at all, that might mean having to buy a minimum of 5m of hose to conform?

 

Unless there is hose that just has 'ISO 7840' marked on it back to back down the entire length?

[Jen-in-Wellies]

44 minutes ago, T_i_m said:

That's the issue Jen, if we need 5 short rubber connections between the various bits (filer / pump / heater), from the 1m length of hose I have here only one would have 'ISO 7840' marked on it?

 

Given that only 50% of the 1m has anything written on it at all, that might mean having to buy a minimum of 5m of hose to conform?

 

Unless there is hose that just has 'ISO 7840' marked on it back to back down the entire length?

Thing to do would be to ask your usual BSS person, or the one you intend to use.

One way round it may be to run the heater from a small (<=10l) tank. Currently, the BSS scheme are OK with unknown spec tanks and hose, on the grounds that the amount of diesel that can leak is limited.

See https://www.boatsafetyscheme.org/media/299305/technical-briefing-21-01-interim-position-on-diesel-appliance-fuel-supply-arrangements-final-draft-modified-on-211208.pdf

 

https://www.boatsafetyscheme.org/media/299306/bss-interim-position-on-diesel-appliance-fuel-supply-arrangements-dec-2021-final-v10-modified-on-211208.pdf

[T_i_m]

7 minutes ago, Jen-in-Wellies said:

Thing to do would be to ask your usual BSS person, or the one you intend to use.

One way round it may be to run the heater from a small (<=10l) tank. Currently, the BSS scheme are OK with unknown spec tanks and hose, on the grounds that the amount of diesel that can leak is limited.

See https://www.boatsafetyscheme.org/media/299305/technical-briefing-21-01-interim-position-on-diesel-appliance-fuel-supply-arrangements-final-draft-modified-on-211208.pdf

 

https://www.boatsafetyscheme.org/media/299306/bss-interim-position-on-diesel-appliance-fuel-supply-arrangements-dec-2021-final-v10-modified-on-211208.pdf

Thanks for the tip but there has to be a more realistic way than that?

 

I mean, unless there is hose out there with the markings every 100mm?

[Ray T]

I had a flexible fuel line made to spec by Pirek, but was told by a BSC bod it would not pass a BSC exam as it was not marked. So off to Midland Chandlers to get a marked one.

 

Edited May 10 by Ray T

[T_i_m]

Just now, Ray T said:

I had a flexible fuel line made to spec by Pirek, but was told by a BSC bod it would not pass a BSC exam as it was not marked. So off to Midland Chandlers to get a marked one.

Out of interest, how much hose did you actually need Ray and did MC stock hose that was continuously marked or did you have to buy more than you needed, just to get a marked bit?

[Ray T]

1 minute ago, T_i_m said:

Out of interest, how much hose did you actually need Ray and did MC stock hose that was continuously marked or did you have to buy more than you needed, just to get a marked bit?

I purchased a stock hose, several lengths here:
Search | Midland Chandlers

[jonathanA]

I think I'd take a pic of the length including markings and use that as evidence that all the short lengths are compliant.

 

Mine are similar to the ones Ray has posted pics of, but they are a decent length rather than short bits. 

[T_i_m]

1 hour ago, Ray T said:

I purchased a stock hose, several lengths here:
Search | Midland Chandlers

Sorry to be a pain but did the hose come with the markings at very short regular intervals or how would one deal with the need for 5 x 70mm lengths of hose, all requiring the right markings?

 

I'm trying to ascertain if there is some 5mm ID ISO 7840 hose that does have that mark continuously down the hose and if such exists, we need to get some!

 

Or rather than having lengths of copper piped joined with short rubber sections, maybe we just run it all in rubber, that way we can reduce the joints and stand a chance of having each section correctly marked?

 

There has to be a more realistic way ...

29 minutes ago, jonathanA said:

I think I'd take a pic of the length including markings and use that as evidence that all the short lengths are compliant.

 

Mine are similar to the ones Ray has posted pics of, but they are a decent length rather than short bits. 

Whilst that makes perfect sense (photographic evidence of it all coming from the same approved length), it would only apply in the same way as a Manufacturers / suppliers decoration might and I don't know how funny these BSS inspectors can be (but from some of the replies here so far, I think 'very' can be an answer). ;-(

Maybe my mates set-up is 'weird' weird in how it's run in copper with the rubber hose joiners but when Iook on-line for similar installations, I see things like this:

 

And this is my mates:

 

 

You can't see the pump and filter in that shot but the copper joins the tank directly with a compression joint, short length of rubber between copper and filter (and the rubber is supposed to only be short to allow the two rigid ends to touch each other to avoid air bubbles etc) and another short coupling to the pump then another from pump to copper then up to the heater and the last rubber coupling.

 

Is that all weird and if not, how is one supposed to find 5 short couplings that conform with Webasto's installation instructions and the BSS? 

 

"FUEL PIPING
The kit is supplied with copper fuel pipe, it is the fitters responsibility to ensure the fuel system meets the correct.
Only fuel lines approved by Webasto may be used.
1. The fuel hose is connected to the standpipe, pump and heater using the 50mm long rubber hose pieces. It is
important to ensure the pipe is correctly inserted into the rubber joiners to prevent air bubbles form forming"

 

 

It really can't be that complicated can it?

Edited May 10 by T_i_m

[T_i_m]

This is my latest bracket to take the filter and fuel pump. It should be easy to fabricate being modular and nuts and bolts, easy to remove for access to the hater or whatever:

 

 

It should bolt to the existing bracket that is welded to the boat and that carries the TTC.

 

Edited May 10 by T_i_m

[Alan de Enfield]

10 hours ago, T_i_m said:

......for access to the hater or whatever............

 

Apparently quite a common name for them !

[T_i_m]

On 11/05/2025 at 09:04, Alan de Enfield said:

 

Apparently quite a common name for them !

Hehe. After taking one to bits, testing and rebuilding I'm not sure why, unless they are also unreliable, even when they are technically running ok. It's such a pleasant change is to find something that old that can still be made to work and work well because there is sufficient support and spares (new and old) are still available.

 

Not such good support from the people I bought the rubber fuel hose from, in spite of explaining why the lack of regular markings could be an issue to some installations and how a simple declaration could overcome that, they just repeated the same thing, 'the markings are on the hose'. You would have thought that might be something they have previously encountered and so already ready for but it seems not (or is it me expecting too much 'these days')?

 

I even supplied them a mostly pre-filled decoration as generated by ChatGPT (that looked pretty thorough) but no, just the same reply.

 

 

DECLARATION OF CONFORMITY

Manufacturer / Supplier:
[Company Name]
[Company Address]
[City, Postcode, Country]
[Phone Number]
[Email Address]
[Company Registration Number]

Declaration Number: [Unique Identifier]

Date of Issue: [DD/MM/YYYY]

Product Description:

Product Name: Fuel Hose

Internal Diameter (ID): 5mm

Type/Model: [e.g., Type A1, A2, B1, or B2, as per ISO 7840 classification]

Length Supplied: [e.g., 25 meters]

Batch/Lot Number: [Batch Number]

Production Date: [Month/Year]

Applicable Standard:

This product conforms to the following international standard:

ISO 7840: [Year] – Small craft — Fire-resistant fuel hoses

Intended Use:

Designed for use in the fuel systems of marine craft, transporting petroleum-based fuels in both petrol and diesel engines, including fuel with ethanol or biodiesel blends.

Conformity Assessment:

The product has been tested and verified for compliance with the requirements of ISO 7840, including fire resistance, pressure integrity, and fuel compatibility.

Testing and conformity have been verified internally or by a notified testing body:

Testing Laboratory (if applicable): [Name and accreditation number]

Test Report Reference: [Reference Number]

Declaration:

We hereby declare that the product described above conforms to the requirements of ISO 7840 and is safe for its intended marine fuel system use.

Signed by:
[Name of Authorized Person]
[Job Title]

Signature: __________________________

Date: [DD/MM/YYYY]

Company Stamp (if applicable)