Various embodiments include an exemplary design of an apparatus and related process to reduce or eliminate de-gassing from a liquid precursor during dispensing of the liquid precursor under vacuum. In one embodiment, the apparatus includes a liquid-flow controller configured to be coupled to a liquid-supply vessel containing the liquid precursor, and at least one valve hydraulically coupled downstream of and to the liquid-flow controller by a liquid line. The at least one valve is to be opened and closed to maintain a minimum pressure that is sufficiently high enough to reduce or prevent degassing of the liquid precursor throughout the liquid line. An atomizer is hydraulically coupled downstream of and to the at least one valve. The atomizer can produce droplets of the liquid precursor and is further to be coupled on a downstream side to a vacuum source. Other methods and apparatuses are disclosed.