This last weekend I installed the filter assembly in the engine room and started the leak tests. This involved…
- bolting the filter assembly to the bulkhead and attaching the supply/return hoses
- dumping about 50 gallons of diesel in the main center fuel tank
- temporarily wiring fuel gauges for all five fuel tanks
The goal here was to test the system for leaks. Particularly the tank selection supply/return plumbing (made up of flare fittings, ball valves, and manifolds. The blue hose stuff in the picture), and especially the fittings at each of the tanks, before they get covered up with more construction.
The procedure was, one tank a time, perform the fuel transfer function to and from the main center tank, while checking for leaks. This also served to purge air from the system, especially the fuel pickup/supply lines which required the primary filters to be manually topped off with fuel between tank tests.
The results so far: no leaks! But, the fuel transfer pump seems awfully slow. It is rated at 43 gallons per hour, which is about .70 gallons per minute. Which means the small 13 gallon day tank should take about 20 minutes to fill. But it is taking longer, a lot longer. I suspect it may be due to air in the return lines, for which I neglected to plumb a means to purge air. Guess I will have to play with it some more.