  We consider acoustic wave transmission in non axisymmetric waveguide which
consists of cylindrical resonator and two semi-infinite cylindrical waveguides
whose axes are shifted relative to the resonator axis and each other by
azimuthal angle $\Delta\phi$. We show that for rotation of one of attached
waveguides the coupling matrix elements of the eigenmodes of resonator
classified by the integer $m$ and propagating mode of the waveguide acquire
phase factor $e^{im\Delta\phi}$. That crucially effect Fano resonances and
creates an analog of faucet opening and closing wave flux under rotation of the
waveguide. We show that under the rotation of the waveguide and variation of
the length of resonator numerous bound states in the continuum occur
complimenting by the Fano resonance collapse.
