  We present preliminary results of our spectroscopic campaign of a group of
intermediate mass interacting binaries dubbed "Double Periodic Variables"
(DPVs), characterized by orbital light curves and additional long photometric
cycles recurring roughly after 33 orbital periods (Mennickent et al. 2003,
2005). They have been interpreted as interacting, semi-detached binaries
showing cycles of mass loss into the interstellar medium (Mennickent et al.
2008, Mennickent & Kolaczkowski 2009). High resolution Balmer and helium line
profiles of DPVs can be interpreted in terms of mass flows in these systems. A
system solution is given for LP Ara, based on modeling of the ASAS V-band
orbital light curve and the radial velocity of the donor star.
