Fuel Tank questions

[Boo2]

Hi,

I'm just about to order a new bespoke fuel tank from Tek-Tanks and I need to decide what fittings to get, engine is a Nanni N.38 marine diesel and the boat is a UFO 34.

The original tank has the fuel feed from front face at the port bottom, return ditto port top, fill on top and vent is on aft face near top port side. I understand that it's now preferred to take all lines from the top of the tank, but space is obviously restricted by the cockpit floor and post-installation access will be non-existant so can anyone tell me how important that actually is in practice ? Do any of the coding rules require it ?

I need to know what fittings to order as well, old tank had the following :

Vent : 1/2 thread fitting in rear face of tank
Fill: 50mm diameter short tube on top of tank. There is a small deck plate central aft in the cockpit covering this.
Feed: fuel cock feeding ?? 3/16" ?? copper pipe, new is 8mm according to engine spec sheet
Return: flexible pipe fitting forgot to measure dia.

Any advice on what to do in terms of fitting types and locationswith the new tank would be gratefully received, especially if there are any UK/international regulations worth knowing about.

Thanks,

Boo2

 

[prv]

Tek Tanks made us a new tank for Kindred Spirit. It was in a different place to the original, so up to me where to put the fittings. It was hard up against the bottom of the gas locker, but about six inches at one end of the top extended past it and had a little space above. I specified all the fittings in a row along this clear band.

How close will the tank be to the deck above? My feed, return, and vent are banjo fittings that project about an inch, maybe a little more, above the top of the tank. The hose comes off parallel to the top face of the tank. Given the height of your filler, it sounds like these would fit?

I specified an access port, one of the black plastic ones with a central bolt. Was very glad of it when we got a bad fill of diesel from the bottom of a nearly-empty fuel barge - I had to dismantle and remove the gas locker to get at it, but the amount of sludge I scooped out of the bottom of the tank made me glad I did. I'd recommend the same if at all possible, though it does sound tricky to arrange in your installation. Either another deck plate, or the ability to shift the tank, I guess.

Pete

 

[NormanS]

I have no idea re current regulations for coding etc, but if it is at all possible, have a small dirt sump and drain valve on the bottom of the tank.

 

[Tranona]

Not sure I would go for top fittings if you do not have access once it is installed as you have no way of cleaning it or dealing with any leaks from the pickup or return. There are no "rules" to comply with and a bottom take off - usually above the bottom so that sludge collects below the outlet is OK.

I suggest you discuss the installation and fittings with Tek Tank as they have the experience to advise the best way of arranging it. I found them very helpful when designing the layout of fittings for my holding tank.

 

[pvb]

I wouldn't have any fittings on the sides of the tank unless they're right at the top edge - the potential for leaks is too great. The TekTanks fittings guide also suggests that fittings have to be on the top of the tank in order to comply with regulations.

In addition to the normal fuel feed, I'd suggest having a second draw-off pipe which goes right down to the very bottom of the tank. If you plumb this to a little brass hand pump, it's very useful for drawing off some fuel every now and then to check for water in the tank.

 

[Stork_III]

My tank has
Fuel feed with tap, with internal pipe just clear of bottom of tank
Fuel return with tap, with internal pipe just clear of bottom of tank
Heater take off with tap, with internal pipe well clear of bottom of tank
Spare with tap, with internal pipe to bottom of tank for pumped draining. A loose L pipe fitting is provided to fit when required.
Fuel fill
Fuel vent

Unfortunately no inspection hatch.

 

[macd]

In addition to the normal fuel feed, I'd suggest having a second draw-off pipe which goes right down to the very bottom of the tank. If you plumb this to a little brass hand pump, it's very useful for drawing off some fuel every now and then to check for water in the tank.

+1
This is a better solution than NormanS's "dirt sump and drain valve on the bottom of the tank".

The brass hand pump might be superfluous: a simple hose (securely clipped) with a tap at the end may well work just as well once primed. Usually, they stay primed thereafter.

 

[Spirit of Glenans]

My previous boat a UFO27 had a retro-fitted tank in stainless steel, wedge -shaped, in the saloon, mounted forward of the bridge-deck and under the companionway steps, leaving access to the engine space underneath. It had a draw-off tap at the bottom, to check for and remove water. The filler was on the side as was the breather, while the fuel out had a tap, the return was tee-d into this pipe downstream of it allowing the fuel mixture to be warm, probably helping combustion. No inspection hatch, although it would have been a very easy job to remove the tank completely in order to remove sludge and clean.

 

[Caer Urfa]

Hi,

Any advice on what to do in terms of fitting types and locationswith the new tank would be gratefully received, especially if there are any UK/international regulations worth knowing about.

Thanks,

Boo2

I have twin 103 litre each Tek tanks and bought the access/inspection hatch, fuel level indicator, ovefill connection etc all from Tec Tanks with the tank.

Like most boats my tanks are tucked under the side decks in my case below lockers, to access the tank top I cut a hole in the locker floor then made a simple plate held by 2 screws to cover the hole, as I only need to access maybe once a year, if that.

I do not recommend you use small bore copper piping, we had problems for months then realized we were not getting fuel starvation from dirty tanks but blockages in the small bore copper piping, so I replaced the lot with certified 3/8" bore rubber fuel pipe.

Also I had problems after I re-positioned fuel filters (higher than the bottom of the tanks), it was not until we finally positioned it so it was 'gravity fed' 'below the bottom' of the tank we solved the problem.

Mike

 

[Boo2]

Can anyone tell me whether I need banjo brass compression assemblies (TT #B08BCT) or will hosetail types be OK (eg TT #FE08B or #E08B) for the fuel feeds and returns ? I'd prefer copper pipe for its fire reistance, applies equally to the return I guess ?


Boo2

 

[sailorman]

Can anyone tell me whether I need banjo brass compression assemblies (TT #B08BCT) or will hosetail types be OK (eg TT #FE08B or #E08B) for the fuel feeds and returns ? I'd prefer copper pipe for its fire reistance, applies equally to the return I guess ?


Boo2

http://www.asap-supplies.com/marine/superflex-fuel-hose-seaflow

Mm too big a hose, but similar available from Pirtec

 

[Boo2]

Also, the tank filler is located under a deck plate in the cockpit sole, I want to use a 50mm fitting but do I need a male BSP socket (TT # 50MMMFSOCKET) or a female one (TT # 50MMFSOCKET) ?

Thanks,

Boo2

 

[Boo2]

Supplier for fuel cocks and pumps ?

Also, can anyone tell me a supplier for fuel cocks and fuel transfer fuel pumps ?

Thanks,

Boo2

 

[Tranona]

Seascrew or ASAP for valves. Pump will depend on how you want to transfer. More sensible to plumb them to a 3 way cock so that you can select the tanks independently. You will also need a 3 way for the returns and fillers, and sensible to have separate filters. That way you have two completely independent supplies of fuel so if one becomes contaminated you can switch to the clean one.

 

[Boo2]

More sensible to plumb them to a 3 way cock so that you can select the tanks independently. You will also need a 3 way for the returns and fillers, and sensible to have separate filters. That way you have two completely independent supplies of fuel so if one becomes contaminated you can switch to the clean one.

Hi Tranona,

Unfortunately the filler is in the cockpit sole with the the main tank immediately below so there is no room to T off the second tank filler. The idea of running two feeds and filters is a good one, I will look into it but I am not sure how it will pan out owing to restrictions on the feed and return pipe runs.

Thanks,

Boo2

 

[Tranona]

How are you going to fill the second tank? Will it be plumbed in to be filled from the same filler and linked in serially? In which case you only need to take the feed off one tank and you won't need a transfer pump. Better if you can to have the new tank completely independent with its own filler.

 

[Boo2]

How are you going to fill the second tank? Will it be plumbed in to be filled from the same filler and linked in serially? In which case you only need to take the feed off one tank and you won't need a transfer pump. Better if you can to have the new tank completely independent with its own filler.

I've decided to mount all vents, feeds and fills etc on the top of the tanks which means dip tubes as required, but also means I can't rely on the connecting pipes being primed, hence a pumped feed/drain to/from the secondary tank.

The more I think about it the less I'm inclined towards separate systems - the pipe runs mean that would be a real palaver with feeds & returns running under the cabin sole boards where there's not much room. With an aux tank setup I can get away with just 3 conections at the rear of the aux tank - fill/drain, vent and overflow which can all be run behind the after bulkhead along with the pump. An independent system does have obvious advantages but it's just too complicated.

Boo2

 

[sailorman]

KISS

 

[Tranona]

I've decided to mount all vents, feeds and fills etc on the top of the tanks which means dip tubes as required, but also means I can't rely on the connecting pipes being primed, hence a pumped feed/drain to/from the secondary tank.

The more I think about it the less I'm inclined towards separate systems - the pipe runs mean that would be a real palaver with feeds & returns running under the cabin sole boards where there's not much room. With an aux tank setup I can get away with just 3 conections at the rear of the aux tank - fill/drain, vent and overflow which can all be run behind the after bulkhead along with the pump. An independent system does have obvious advantages but it's just too complicated.

Boo2

Getting confused now. If you are having take offs from both tanks then you need two independent systems with a 3 way valve so that you can select from one or the other. Otherwise how will you determine which tank is feeding the engine? It can only take from one source at a time. The alternative is to have the two tanks permanently connected so that they are effectively one tank and you only need to draw from one. However the problem with this arrangement is ensuring that both tanks are full from one filler and fuel is drawn equally from both tanks. It is possible to have the new tank completely separate with its own filler and just a takeoff and pump to transfer fuel from that tank to the main tank. Simpler but does not give the advantage of independent supplies.

 

[NormanS]

+1
This is a better solution than NormanS's "dirt sump and drain valve on the bottom of the tank".

The brass hand pump might be superfluous: a simple hose (securely clipped) with a tap at the end may well work just as well once primed. Usually, they stay primed thereafter.

I'm intrigued. Why is a "brass hand pump" a better solution than gravity?
With a sump at the bottom of the tank, which used to be standard, any dirt or water will automatically find its way into the sump, from which it is drawn off.