  We study a specific version of $SU(2)_R \times SU(2)_L \times U(1)_{B-L}$
models extended by discrete symmetries where the new physics sector responsible
for tiny neutrino masses at leading order remains decoupled from the new
physics sector that can give rise to observable signatures of lepton number
violation such as neutrinoless double beta decay. More specifically, the
dominant contribution to light neutrino masses comes from a one-loop Dirac
mass. At higher loop level, a tiny Majorana mass also appears which remains
suppressed by many order of magnitudes in comparison to the Dirac mass. Such a
model where the active neutrinos are predominantly of Dirac type, also predicts
observable charged lepton flavour violation like $\mu \rightarrow 3e, \mu
\rightarrow e \gamma$ and multi-component dark matter.
