Fuel Injector Leak Off Pipes

[Breals]

Just a quickie. My leak off pipes from the fuel injectors were leaking, and I'm having them repaired. The mechanic is having trouble sourcing pipes that screw on in the same way as the old ones did, and wonders whether normal push-on type pipes will suffice. Is this OK for inland waterways engines?

[Sir Nibble]

The pipes have to be fireproof to be BSS compliant.

[John Orentas]

Hi Breals.

 

You probably know this question is a bit complicated or you would not have brought it up, a few years ago the BSS made one of their pronouncements that all spill pipes must be metallic regardless of the fact that some of the engine manufacturers fitted pipes that were made from other materials. Many individuals and engine marinisers went to a great deal of trouble to comply with the new regulation and conversion kits came onto the market which required retro-fitting, the kits in some cases cost several hundreds of pounds.

 

Then problems started, some of the new compliant spill pipes suffered metal fatigue and began to fail, had they consulted the manufacturers before hand they would have been warned of that. The BSS began to back pedal rapidly and issued guidance to the effect that if an engine was originally fitted with non metallic pipes they could or should be fitted to the engine. No admission off course that the people who designed and manufactured the engines in the first place knew better than they did, nor that they had made another stupid error.

 

You will see now that the Red Book contains all manner of vague and contradictory regulations including contacting the BSS office for guidance. Quite why some character sitting behind a desk should know more than the people who work on the engines full time I don't know. I think it is back to making sure your engine is soundly manufactured and maintained and then convincing the examiner of that fact.

Edited October 10, 2006 by John Orentas

[alan_fincher]

Just a quickie. My leak off pipes from the fuel injectors were leaking, and I'm having them repaired. The mechanic is having trouble sourcing pipes that screw on in the same way as the old ones did, and wonders whether normal push-on type pipes will suffice. Is this OK for inland waterways engines?

 

I would have said "no", knowing there have been issues about this in the past.

 

However the latest BSS guide actually says.....

 

"Injector leak-off (spill rail) arrangements having push-on connections on flexible fuel lines are acceptable for options covered by the bullet points at Checklist Item 2.10.5."

 

and the "bulleted" part of 2.10.5 says.....

 

Injector leak-off (spill rail) arrangements must meet all the requirementsfor fuel feed and return pipes, flexible hose and connections; or,

. utilise the direct return to tank; or,

. return to the fuel system through a non-return valve.

 

So on the face of it, I'd say that provided the pipe is of an approved type, the answer might even be "yes".

 

 

HOWEVER,

 

A search facility on the site also turned up the following...

 

"Where flexible hoses are connected to rigid components of the fuel system, e.g. pipes and filters, the connections must be made with metallic clamps onto proper hose nozzles. It's not acceptable to just push a flexible hose over the bare end of a rigid pipe - even if a clamp is used! [2.15"

 

on what looks like possibly an old version of the guide, (but still found by search).

 

In a way that contradicts what seems to be in the latest guide, (or to my simple brain anyway...).

 

So I don't think there's a clear answer, and I think you need to seek clarification from the BSS people, unfortunately.

 

Alan

 

FURTHER EDIT

************

 

On looking further, I think it is another of these confused cases where the BSS peeps say one thing for Private craft, (which have a new 2005 version of the guide), and stick to something different for the regs still covering Hire Craft and Work Boats, (where they are still using a 2002 document).

 

In the latter case there is a section that says....

 

"Spill racks (i.e. the pipes which are attached to, and carry return fuel from, the

injectors on diesel engines) must be made from metallic pipe or fire resistant

hose. Some automotive engines currently on the market, which have been

adapted for marine use, are fitted with push-on, non-fire resistant hose. This

arrangement is unacceptable. Conversion kits are available for most engines"

 

so it looks like hire craft may have more stringent requirements still than a private boat.

 

I still think you need to try and get them to clarify.

 

(It's never easy, is it ?).

Edited October 10, 2006 by alan_fincher

[Breals]

Thanks for that Alan - I think!!!

[smileypete]

Thanks for that Alan - I think!!!

 

Hi,

 

This may help:

 

http://www.britishmarine.co.uk/DocImages/F...load.asp?id=302

 

It should start a small PDF download, if not I could upload it somewhere.

 

cheers,

Pete.

[Breals]

John - that is interesting background info; I agree a lot of these regs seem to be there just to make life awkward. I am asking on behalf of my mechanic, who very conscientously wants to do a job which won't fall foul of the regs.

 

Pete - that looks very useful, I'll print that off for the mechanic to look at.

[Hairy-Neil]

I agree a lot of these regs seem to be there just to make life awkward.

 

You'd not so keen to say that if you had an engine fire half way through Harecastle Tunnel......

[John Orentas]

You'd not so keen to say that if you had an engine fire half way through Harecastle Tunnel......

 

 

You mean your spill pipes surrendering to metal fatigue because some half witted non engineer has been given the authority to legislate on things he knows nothing about.

 

Stop by a motorway and watch all those lorries thundering by, who's engineering expertise would you rather trust, the chaps who designed those things or the little pen-pusher in Watford.

Edited October 11, 2006 by John Orentas

[Sir Nibble]

Stop by a motorway and watch all those lorries thundering by, who's engineering expertise would you rather trust, the chaps who designed those things or the little pen-pusher in Watford.

I agree entirely with the point you make John, but as a vehicle repair man I have to say I wouldn't trust the vehicle designers further than I could spit a rat!

There is no interest in designing a functioning reliable mechanism, the imperative is to ditch what has worked for years to replace it with something new that doesn't in order to win an award.

[Breals]

You'd not so keen to say that if you had an engine fire half way through Harecastle Tunnel......

 

Well, the original regs were onerous. After years of making people comply, the BSS have found a solution which is practicable and equally safe (see the link above)... but if you look at Alan's extracts from their website, there is still some confusion.

[Chris M]

Just a quickie. My leak off pipes from the fuel injectors were leaking, and I'm having them repaired. The mechanic is having trouble sourcing pipes that screw on in the same way as the old ones did, and wonders whether normal push-on type pipes will suffice. Is this OK for inland waterways engines?

 

I've been there done that, got the T Shirt back in March.

My engine has the standard Bosch push on rubber hose which needed replacing before my BSS test.

The hose was directly connected into the return fuel line at the injector pump via a banjo fitting with 2 connections.

I replaced the banjo connection and then added a T and non return valve in the return line as described.

It passed the BSS test.

To answer your question, with the non return valve fitted the spill pipes can be literally any old hose without clips to hold them on, within reason of course.

 

At the time I'd not seen the document posted above stating the Delph part number for the check valve. I approached a local hydraulics supplier for a check value and he offered several suitable valves with serveral different internal sealing types. I contacted the BSS office to find out what to use and they couldn't give me an answer! They did however point me towards a diesel specialist. The BSS tester wasn't in the slightest bit bothered whether the valve was suitable. He was just happy that there was one there.

[Hairy-Neil]

There is no interest in designing a functioning reliable mechanism, the imperative is to ditch what has worked for years to replace it with something new that doesn't in order to win an award.

 

Or to save 0.000001 pence per vehicle in the manufacturing process.....

[smileypete]

John - that is interesting background info; I agree a lot of these regs seem to be there just to make life awkward. I am asking on behalf of my mechanic, who very conscientously wants to do a job which won't fall foul of the regs.

 

Pete - that looks very useful, I'll print that off for the mechanic to look at.

 

Hi

 

You might want to show it to the BSS examiner before they examine your boat, too. They might have their own ideas on what hose and check valve is acceptable too, so it could be worth clearing it with them beforehand.

 

BTW has anyone experienced or heard of an engine fire on a diesel engined inland waterways boat, in the UK?

 

cheers,

Pete.

[John Orentas]

Hi

 

You might want to show it to the BSS examiner before they examine your boat, too. They might have their own ideas on what hose and check valve is acceptable too, so it could be worth clearing it with them beforehand.

 

BTW has anyone experienced or heard of an engine fire on a diesel engined inland waterways boat, in the UK?

 

cheers,

Pete.

 

I suspect that thimble-full of fuel that leaks from your injector during the course of a days cruising would errupt into to a fire-ball. All it needs to start a fire is for it to be atomised and the resultant mixture compressed to 300 pounds per square inch, if other conditions are met - ka-pow.

 

A bit like American cars when they run of the road in the good old Holywood culture.

[Hairy-Neil]

I suspect that thimble-full of fuel that leaks from your injector during the course of a days cruising would errupt into to a fire-ball. All it needs to start a fire is ......

 

Nuneaton's leak off from the Petter PD2 used to fill a coke can in a day. I know because I rigged up the coke can to catch it on one of my first trips. Previous to that it worked on a total loss system......

 

Remember though where fire is concerned, from little acorns....

Edited October 11, 2006 by Hairy-Neil

[Breals]

I should really have let you know how this ended up. The mechanic was extremely careful to ensure the pipes would be BSS compliant. In the end we fitted rubber pipes with a non-return valve. The only problem we had was getting the engine started after sitting cold and unused for a couple of months!

[David]

Hi

Absolutly nothing to do with the question of leak off pipes, but just to say our examiner was quite happy with the Kelvin arrangement which is leak off pipe first goes into the governer which has a nice little flip up lid to check it is full prior to starting (no diesel in there and engine would "run away" on starting). Governer has a overflow pipe at the top which dumps the diesel into a Whisky bottle (this needs to be a Teachers whisky for historic reasons).

I would point out that the "return" diesel is only a very small amount just for a few seconds whilst the engine starts and warms up on petrol and a drop or two as the engine is stopped, unlike modern engines . On a normal start up and stop this would amount to a total of less than a small eggcup full.

David

[NB Alnwick]

Governer has a overflow pipe at the top which dumps the diesel into a Whisky bottle (this needs to be a Teachers whisky for historic reasons).

 

Don't make the mistake of drinking it - I am told it had a sobering effect on Scottish fishermen . . .

[Tony Brooks]

Hi

Absolutly nothing to do with the question of leak off pipes, but just to say our examiner was quite happy with the Kelvin arrangement which is leak off pipe first goes into the governer which has a nice little flip up lid to check it is full prior to starting (no diesel in there and engine would "run away" on starting). Governer has a overflow pipe at the top which dumps the diesel into a Whisky bottle (this needs to be a Teachers whisky for historic reasons).

I would point out that the "return" diesel is only a very small amount just for a few seconds whilst the engine starts and warms up on petrol and a drop or two as the engine is stopped, unlike modern engines . On a normal start up and stop this would amount to a total of less than a small eggcup full.

David

 

 

A warning to this and the other statement about the return only being a small amount.

 

This is true as long as the pipes in question are ONLY injector spill off pipes and go straight back to the tank, however in many engines the spill system is also used to vent any air that gets entrained in the diesel supply back to the tank. This will be fine as Long as the non-return valve is between the injectors and the vent system. but many engines with metal pipes do not use such a valve (BMC, Beta, Bukh & Vetus to name a few). A split leak of pipe in this case will spray fuel all over the engine supplied by the lift pump.

 

 

So if you are using a non-return valve get it in the safe place.

 

Tony Brooks