Extra Diesel Tank Plastic

[Clodi]

I am considering  fitting an extra diesel tank primarily for the Central-heating. I would like to interconnect to the main fuel tank and be filled via the existing tank.

I've always used Tek-Tanks or Cak-tanks in the past but I don't know the BSS regs concerning installation on narrow-boats, Has anyone fitted an extra tank recently and are there any pitfalls lurking?

I seem to recall there was a problem with glass-bowel fuel filters and plastic fuel pipes and Ebers?

Forgive the grammar I'm using Suzuki voice txt

[Boater Sam]

Fuel tanks and pipes on canal boats to BSS have to be metal unless they are flexible hoses then there is another standard. Mechanical joints only, no soldering, though I think brazed is allowed.

Filter bowls in glass were not allowed but I think that may have been relaxed. The drain screws in agglomerators are plastic as supplied, have to be changed to metal.

[Jen-in-Wellies]

Boat safety scheme requirements can be downloaded. Diesel tank materials are:

Materials obviously suitable for diesel include:
• aluminium alloy
• ‘CE’ marked plastic
• FRP
• mild steel
• stainless steel.

 

If your tank is CE marked from a known manufacturer and marked as suitable for diesel, then it should be OK I'd have thought. Lots of diesel cars running around with plastic tanks, so there are plastics suitable. Also bits in the requirements about fillers, vents, connections and balancing pipes that will be relevant to you.

 

Not sure I see any advantage in connecting the two tanks. It will introduce several new joints and pipework at a low level with BSS requirements on materials and methods. If any fail, then the entire contents of both tanks are dumped in to the bilge. This is why there are so many BSS requirements around link pipes! In addition, a separate heating tank means fewer arguments about putting zero percent propulsion duty red diesel in it. If you ever did want to transfer fuel from one to the other, then a jiggle syphon and jerry can will do the job. If you use the existing filler to fill both tanks, then you'll still need to install a compliant vent system to the new tank.

 

Jen

Edited August 20, 2018 by Jen-in-Wellies

[stegra]

I can't help with the regs but I found that FloatYourBoat had a good range of plastic fuel tanks at reasonable prices. 

[Clodi]

Great site, thank you. I've been told by a boatyard that plastic tanks are better than steel as they don't suffer from condensation. I haven't researched that claim yet though.

[Mike Hurley]

Pretty much all cars nowadays have plastic tanks, diesel and petrol.

[Clodi]

1 hour ago, Jen-in-Wellies said:

Boat safety scheme requirements can be downloaded. Diesel tank materials are:

Materials obviously suitable for diesel include:
• aluminium alloy
• ‘CE’ marked plastic
• FRP
• mild steel
• stainless steel.

 

If your tank is CE marked from a known manufacturer and marked as suitable for diesel, then it should be OK I'd have thought. Lots of diesel cars running around with plastic tanks, so there are plastics suitable. Also bits in the requirements about fillers, vents, connections and balancing pipes that will be relevant to you.

 

Not sure I see any advantage in connecting the two tanks. It will introduce several new joints and pipework at a low level with BSS requirements on materials and methods. If any fail, then the entire contents of both tanks are dumped in to the bilge. This is why there are so many BSS requirements around link pipes! In addition, a separate heating tank means fewer arguments about putting zero percent propulsion duty red diesel in it. If you ever did want to transfer fuel from one to the other, then a jiggle syphon and jerry can will do the job. If you use the existing filler to fill both tanks, then you'll still need to install a compliant vent system to the new tank.

 

Jen

Thanks Jen, your advice regarding link pipes are very true. I guess I'm not really used to only having one engine and one tank. I shall definitely not now link the tank