It makes no engineering sense to me, for the tubes to be
Permanently sealed. IF the tubes were sealed at the factory, AND were pressurized, they would likely be "charged" with Dry Nitrogen. To do this, a "special" charging valve would be required and the AIR in the tube "evacuated".. before the nitrogen is introduced. The Only advantage to charging the tubes with dry nitrogen would be to
prevent corrosion inside the tube. I highly doubt the factory would consider this "practicle". BTW: Any internal bulkheads/baffles will have "Limber Holes" to allow water to drain aft in a controlled manner.
It
Would make perfect sense..both from the factory's/dealers point of view (future warranty work).. and the owners convenience, to provide access ports (with screw in covers and gaskets) on the top of the tubes to allow pumping the tubes out if required. Just a thought..
NB
PS: Sea Plane floats have such access ports on the top.
