Been out of the loop for 4 years what is the situation with Carbon Fiber Tanks?

[Mod63]

You have to be extremely careful when diving with them in salt water since any defect in the composite will invite salt crystals to enter the composite matrix and when they dry, they will start to abrade the carbon fibers themselves. There is a reason they haven't come to the US yet for scuba use...

No such issues here, and they are used heavily in salt water.
One question to clarify:
Are we talking "pure" CF tanks like they are used by firefighters etc. or the Carbondive tanks, which are steel at the core and CF wrapped?

 

[tbone1004]

No such issues here, and they are used heavily in salt water.
One question to clarify:
Are we talking "pure" CF tanks like they are used by firefighters etc. or the Carbondive tanks, which are steel at the core and CF wrapped?

both apply, and unless you have $100k+ testing equipment you have no idea if it's an issue or not, but I guarantee that there are imperfections in the composite. I have done a lot of development work on pure composite and hybrid pressure vessel designs, it's there. You won't catch me using them.

 

[rjack321]

No such issues here, and they are used heavily in salt water.
One question to clarify:
Are we talking "pure" CF tanks like they are used by firefighters etc. or the Carbondive tanks, which are steel at the core and CF wrapped?

have seen many pictures of smaller carbondive CCR cylinders which have clearly failed exactly as @tbone1004 has described

don't expect them to last more than about 8 to 15 years max

 

[Martijn]

[...] also RIP your first stage service life.
[...]

Why? Plenty of regs that are rated and used for 300bar ...

 

[Pkishino]

Ultra light fill composite tanks from interspiro with unlimited service life are used quite a bit in the Swedish armed forces, both by disposal divers, working and attack divers.

 

[tbone1004]

Why? Plenty of regs that are rated and used for 300bar ...

They are, but it wears the HP seats out much faster. If you follow the manufacturers service interval it's not a problem

Ultra light fill composite tanks from interspiro with unlimited service life are used quite a bit in the Swedish armed forces, both by disposal divers, working and attack divers.

They are not treated as unltd service life by the military