  Absorption line spectroscopy using background quasars can provide strong
constraints on galactic outflows. In this paper, we investigate possible
scaling relations between outflow properties, namely outflow velocity \Vout,
the mass ejection rate $\dot M_{\rm out}$, and the mass loading factor $\eta$
and the host galaxy properties, such as star formation rate (SFR), SFR surface
density, redshift, and stellar mass using galactic outflows probed by
background quasars from MEGAFLOW and other surveys. We find that $V_{\rm out}$
($\eta$) is (anti-)correlated with SFR and SFR surface density. We extend the
formalism of momentum-driven outflows of Heckman et al. to show that it applies
not only to down the barrel studies but also to winds probed by background
quasars, suggesting a possible universal wind formalism. Under this formalism,
we find a clear distinction between ``strong'' and ``weak'' outflows where
``strong'' outflows seem to have tighter correlations with galaxy properties
(SFR or galaxy stellar mass) than ``weak'' outflows.
