NEW FUEL LINES HARDWARE AND INFORMATION

Having cut my copper lines many years ago when I started rebuilding the hull from the deadwood up, it was time to redesign and install a new system. I had a flaring tool for the 5/16 inch copper tubing, but the more I researched the more impressed I was with USCG Type A1 fuel lines (which are required by law if you use flexible hose instead of copper). Hoses like this were just not available back in 1967 when the boat was built. So to and from the tank (remember, not all the diesel fuel is injected into the cylinder, so there must be a return line) is now a series of devices connected by double clamped hose over 5/16 inch barbs. I bought about 50 feet of 5/16 Trident Barrier which runs from $1.50 to $2.00 dollars a foot, which left me some to spare for repair. I also bought some double barb fittings (barbs in both directions) in cast I needed to make a repair.
I originally gave information about the different types of compressional fittings used for copper, but upon further study it became obvious that I did not know what I was talking about, so I deleted it the next morning. NOW I understand the value of my conversion to A1 hose - there are no compressional fittings, only NPT pipe threads, and barbs. The advantage of pipe threads is with a little pipe dope they seal themselves, without the compressional fittings required for copper or the bending). One draw back is that NPT do not use the 5/16 dimension, with standard dimensions going from 1/4 to 3/8 - so I had to choose fuel tank selectors that were 3/8. It was not a problem though because 5/16 barbs are readily available on 3/8 threads.
So my new design was this. For $150 more dollars I could buy another Cummin's filter head and bracket, which used a 20 micron filter with water separator (readily available for $14 dollars at autoparts stores), as well as a 12 volt micro pump I could use for a lift pump. So with that in mind I set up two completely separate but identical fuel systems, one for each tank - with the ability to switch in between them.
The letters on the photo trace the path of the port tank from tank (A) through selector (BC) through filter (DE) - (lift pump goes after the water separator filter so it won't break up water droplets)- through lift pump (FG), and on to the engine (another filter, then injector pump to injectors, AND THEN WHAT WAS NOT BURNED STARTS THE RETURN PATH TO THE TANK via the return selector (HI) and back to the tank return K (sorry I left out "J"). That means I wonder what would happen if I burned all the fuel out of the 100 gallon tank but had the return selector on the 50 gallon tank.
The other unused barbs form the same system, complete, for the stb tank.
Forgot to get a shut off that goes right before each primary filter - will remedy.