Diesel fuel tanks

Hey guys, not sure if this is the right place for this question but here goes-

For my project boat I have two aluminum tanks for diesel fuel. They are brand new. I was speaking to a friend of mine who mentioned installing clean outs. Is it just as simple as cutting a hole of adequate size and installing a larger "patch" of equal material? What fasteners would be best? Would I also need some sort of gasket?

 

Hey Sparky,
I myself built a fuel manifold where I could isolate each tank, and I placed a separate Racor on board where I could polish fuel with an electric fuel pump. Easier to install and monitor.

 

Are the tanks built out of 1/8 inch aluminum?
Have you ever installed aluminum tanks in a boat?
If the tanks are 1/8 inch, it is more difficult to install cleanouts in the tanks. Generally they should be installed between each baffle so each area can be cleaned. If you were building the tanks from scratch, you could have included a backing plate
in the inspection plate area to stiffen the 1/8 sheet so that when you bolt up the outer inspection cover, tank will be stiff enough to compress the gasket somewhat
The cover plate should be at least 3/16 inch but even 1/4 if the hole is say larger than 8 inches.

The inspection plate should be on top of the tanks but with diesel can be on the side. If they are on the side, then you should ensure that the area that you are installing them are not prone to flex. Ie properly stiffened mounting flanges

As to the installation of the tanks, there are a couple of threads on this site, search them and you will find information about the proper mounting of the tanks. Also google Steve D'Antonio," installation of aluminum marine tanks" and you
should find some information regarding the proper installation. But I do not believe that he mentions that every spacer, isolation strip, bottom support etc has to be glued to the tank to inhibit water contact with the tank.

If you cannot find the info, certainly come back to this thread

A couple of pertinent points
1) always use marine grade, specified hose
2) Stainless worm clamps must have a stainless worm as well, automotive types are often not though the WORM is just zinc dipped
3) aluminum fittings or stainless fitting only, never brass
4) never cork/rubber gaskets for sending units, rubber only
5) double clamps on fill hose
6) vent lines, 5/8 and must not have a low dip in them as they rise to the vent
7) best to put a strap around the tank, for mounting, but isolated with a uhmw plastic strip glued to the tank, (as compared to putting a bolt through a bracket welded on the tank
8) new rules to meet ABYC requirements, the fill is a non-venting type, the vent vents through a canister, might be charcoal. Perhaps you do not need to be compliant but a smart surveyor, if you need a surveyor for insurance purposes might catch this
9) the tank cannot just sit on a solid flat surface

 

I am interested in the pump you have, can you give me details'; manufacturer, model, voltage etc.

Barry, installing tanks are nothing new to me, but thanks for the links. I'll do a quick refresher. I have done only gasoline in the past and it's been a few years.

I've thought about this some more and I probably won't do the inspection hatches on the tanks I have. There are thousands out there that are decades old and have few issues, at least the ones I've heard about. Final decision will depend on if I can get a third tank to fit properly in between the center stringers and pre-filter (polish) fuel supplying the engine, sort of day tank if you will. Up here where I do most of my boating in the late fall it is usually short distance trips. I will need to have that one fabricated and will include a low point for water to collect as well as a tube to take occasional samples.

Thank you for the replies.

 

I bought it at a local auto parts store. There are so many diesel pickups on the road they are readily available. Make sure you use one that is diesel designated. The electric fuel pump also helps you prime your engine's fuel system after fuel filter changes etc.

 

I have heard they should be mounted lower than the engine fuel pump in accordance qith coast guard rules

 

mythology

 

Thats what ive heard that the line to engine fuel pump should be elevated in case of leak.

 

I could not find anything in ABCY 2008 Standards for this for DIESEL

 

This is not required by ABYC, USCG Regulations for recreational Boats or 46 CFR Subchapter T for passenger vessels. See
46 CFR 182.455 - Fuel piping. https://www.law.cornell.edu/cfr/text/46/182.455
33 CFR Part 183, Subpart J - Fuel Systems https://www.law.cornell.edu/cfr/text/33/part-183/subpart-J

Perhaps this comes from the recurring myth that all fuel lines must have an anti-siphon valves. This is only required if the fuel source is higher than the fuel inlet (at the fuel pump). If the fuel inlet is higher than the withdrawal fitting on the fuel tank, then it is not required. Other that that, someone is feeding you misinformation. Fuel lines typically run uphill, so that if the engine stops, the fuel drains back downhill, but that is not written in any rules. Fuel lines can run uphill or downhill. Placement of the fuel pump is regulated. Fuel pumps on gasoline engines must be within 12 inches or mounted on the engine.

The USCG does not have regulations for diesels on recreational boats. ABYC does in H-33. There are USCG rules for passenger carrying vessels. Those carrying more than 12 passengers for hire must comply with Subchapter T. Those carrying less than 12 must comply with ABYC H-24 for gasoline fuel systems (as well as the regulations in 33 CFR Subpart J) or ABYC H-33 for diesels.