Under most codes CI is not allowed for use in pressure containment.
There are some exceptions, but those are special.
In practice if pressures are very low it might work.
One of the problems is that CI will not tolerate any tensile, flexing, or impact.
Making this a risky move for fuel.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed