Originally Posted by WesK
The vent has to be at the top of the tank or it won't vent at all. The fill will work lower but it will work best at the top where there is no resistance to the flow. Like pouring water into a bucket.
I had a chance to examine my vent outlets the other day. There is a metal cover with the opening pointed down and aft as one might expect but there is also a restriction on the boat hull itself, presumably to further prevent water from entering. This effectively reduces the cross section of the vent and may be part of my fueling problem. I don't see an easy solution though.
I know that...but that doesn't stop some tank manufactures from sticking a pipe into a hole and welding it up without due regard. It will vent till almost full , then it won't, and splash may result from the fill hole....happened to the assistance towboat I used to drive all the time.
If the vent is that way and on the lower end of the tank, and the fill is done right...well....physics.
I work for a company that does salvages and winds up with dozens of all different kinds of boat fuel tanks every year. Most are cut up for scrap so its easy to see manufacturing defects.